Artykuły w czasopismach: „Micro-electro mechanical system - Radio frequency”

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Li Muhua, 李沐华, 赵嘉昊 Zhao Jiahao i 尤政 You Zheng. "Loss mechanisms of radio frequency micro-electro-mechanical systems capacitive switches". High Power Laser and Particle Beams 27, nr 2 (2015): 24132. http://dx.doi.org/10.3788/hplpb20152702.24132.

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Shirane, Atsushi, Yutaka Mizuochi, Shuhei Amakawa, Noboru Ishihara i Kazuya Masu. "A Study of Digitally Controllable Radio Frequency Micro Electro Mechanical Systems Inductor". Japanese Journal of Applied Physics 50, nr 5S1 (1.05.2011): 05EE01. http://dx.doi.org/10.7567/jjap.50.05ee01.

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Shirane, Atsushi, Yutaka Mizuochi, Shuhei Amakawa, Noboru Ishihara i Kazuya Masu. "A Study of Digitally Controllable Radio Frequency Micro Electro Mechanical Systems Inductor". Japanese Journal of Applied Physics 50, nr 5 (20.05.2011): 05EE01. http://dx.doi.org/10.1143/jjap.50.05ee01.

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Cho, Hyunok, Minkyu Yoon i Jae Yeong Park. "Radio Frequency Micro-Electro-Mechanical System Capacitive Shunt Switch Using Actively Formed Wrinkled Hinge Structures". Journal of Nanoscience and Nanotechnology 16, nr 11 (1.11.2016): 11425–28. http://dx.doi.org/10.1166/jnn.2016.13522.

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Sharma, Ashish Kumar, i Navneet Gupta. "Analytical Modeling for Spring Constant of Non-Uniform Serpentine Radio Frequency-Micro Electro Mechanical System Switch". Advanced Science, Engineering and Medicine 5, nr 12 (1.12.2013): 1322–25. http://dx.doi.org/10.1166/asem.2013.1433.

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Sampe, Jahariah, Noor Hidayah Mohd Yunus, Jumril Yunas i Ahmad G. Ismail. "Design and performance of radio frequency micro energy harvesting MEMS antenna for low power electronic devices". Jurnal Kejuruteraan 35, nr 2 (30.03.2023): 265–73. http://dx.doi.org/10.17576/jkukm-2023-35(2)-01.

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Radio Frequency (RF) ambient energy has become the choice as a source of green energy for energy harvesting systems due to the existence of electromagnetic wave signals that are always present in the environment without incurring cost. This RF energy is very low usually less than 190 µW. However, the antenna needs to supply sufficient power to the RF energy harvesting system to power low-power electronic devices. Therefore, the antenna needs to be designed to capture and transfer energy to the RF micro energy harvesting circuit to supply optimal power to the electronic device. The micro-strip antenna design using Micro Electro Mechanical (MEMS) fabrication technology process is the most suitable choice because of its small size, light weight and high performance. This MEMS antenna design uses Computer Simulation TechnologyMicrowave-Studio software(CST-MWS). Comparisons were made for four types of antennas namely silicon surface micromachine, silicon bulk micro-machine with air cavity, glass surface micro-machine and RT/Duroid 5880 as reference. The simulation results show that the glass surface micro-machine antenna is the smallest in size compared to the other three antennas. The return loss of this antenna is also better which is increased by 55.1% and 5.6% compared to silicon surface micro-machine antennas and conventional RT/Duroid antennas respectively. The antenna also has a large bandwidth of 117 MHz, a gain of more than 5 dB and a direction of more than 5 dBi. The glass surface micro-machine antenna has been successfully fabricated using MEMS technology which produces a transparent antenna measuring (L/W) 19 mm x 19 mm. This small sized MEMS antenna is highly sensitive and highly effective for capturing ambient RF signals and is capable of supplying sufficient power to the RF energy harvester system.

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Mizuochi, Yutaka, Shuhei Amakawa, Noboru Ishihara i Kazuya Masu. "Radio Frequency Micro Electro Mechanical Systems Inductor Configurations for Achieving Large Inductance Variations and HighQ-factors". Japanese Journal of Applied Physics 49, nr 5 (20.05.2010): 05FG02. http://dx.doi.org/10.1143/jjap.49.05fg02.

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Figur, S. A., F. van Raay, R. Quay, L. Vietzorreck i V. Ziegler. "Simulation of RF MEMS based matching networks and a single pole double throw switch for Multiband T/R Modules". Advances in Radio Science 11 (4.07.2013): 197–206. http://dx.doi.org/10.5194/ars-11-197-2013.

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Abstract. This work presents concepts and designs for two essential components of a frequency agile transmit and receive module based on Radio Frequency Micro Electro Mechanical System (RF MEMS) switches for the frequency range from 3.5 GHz up to 8.5 GHz. The advantages of a variable power amplifier (PA) matching compared to a fixed broadband solution are examined and discussed in context with the designed components. To demonstrate the principle functionality, an assembly concept is presented, which allows for the integration of a frequency agile 6 W power amplifier with surrounding components like phase shifters, switches and antennas. An RF MEMS switching element is introduced as a high isolation polarization switch, featuring low insertion loss as well as almost no DC power consumption.

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Sheng, Zhong Qi, Ze Zhong Liang, Chao Biao Zhang i Liang Dong. "LabVIEW-Based Wireless Monitoring System of CNC Machine Tools". Applied Mechanics and Materials 121-126 (październik 2011): 2075–79. http://dx.doi.org/10.4028/www.scientific.net/amm.121-126.2075.

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As the development of industry wireless networks, sensor network, innovative sensors, radio frequency identification (RFID), and micro-electro-mechanical system (MEMS) technologies, the industry sector has made great progress in data acquisition, treatment, transfer and analysis, greatly expanded people’s ability to access information, and to control and use them. This paper developed a wireless data acquisition and storage system of CNC machine tools based on LabVIEW graphical programming language and IEEE 802.11 wireless communication protocol, effectively expanded the ability to access and use the CNC machine status information; solved the problem of data collection caused by the environment complexity of manufacture workshop and the hardness of wiring; eliminated the dead zone of manufacture workshop in the processing of the data acquisition of state information of bottom processing equipment; made the bottom machining unit no longer be the information island for manufacturing enterprises.

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Papandreou, Eleni, George Papaioannou i Tomas Lisec. "A correlation of capacitive RF-MEMS reliability to AlN dielectric film spontaneous polarization". International Journal of Microwave and Wireless Technologies 1, nr 1 (luty 2009): 43–47. http://dx.doi.org/10.1017/s1759078709000154.

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This paper investigates the effect of spontaneous polarization of magnetron-sputtered aluminum nitride on the electrical properties and reliability of Radio Frequency – Micro-Electro-Mechanical Systems capacitive switches. The assessment is performed with the aid of application of thermally stimulated polarization currents in metal-insulator-metal capacitors and temperature dependence of device capacitance. The study reveals the presence of a surface charge, which is smaller than that expected from material spontaneous polarization, but definitely is responsible for the low degradation rate under certain bias polarization life tests.

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De Angelis, Giorgio, Andrea Lucibello, Emanuela Proietti, Romolo Marcelli, Giancarlo Bartolucci, Federico Casini, Paola Farinelli i in. "RF MEMS ohmic switches for matrix configurations". International Journal of Microwave and Wireless Technologies 4, nr 4 (sierpień 2012): 421–33. http://dx.doi.org/10.1017/s1759078712000074.

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Two different topologies of radio frequency micro-electro-mechanical system (RF MEMS) series ohmic switches (cantilever and clamped–clamped beams) in coplanar waveguide (CPW) configuration have been characterized by means of DC, environmental, and RF measurements. In particular, on-wafer checks have been followed by RF test after vibration, thermal shocks, and temperature cycles. The devices have been manufactured on high resistivity silicon substrates, as building blocks to be implemented in different single-pole 4-throw (SP4 T), double-pole double-throw (DPDT) configurations, and then integrated in Low Temperature Co-fired Ceramics (LTCC) technology for the realization of large-order Clos 3D networks.

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Chan, King Yuk “Eric”, i Rodica Ramer. "Millimeter-wave reconfigurable bandpass filters". International Journal of Microwave and Wireless Technologies 7, nr 6 (9.09.2014): 671–78. http://dx.doi.org/10.1017/s1759078714001214.

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Millimeter-wave reconfigurable bandpass filters with the ability to operate between 60 GHz and the E-band, capable of providing good channel isolation, are presented. A fully integrated filter with all reconfigurable elements embedded for compactness and a switchable filter that uses radio frequency micro-electro-mechanical system (RF MEMS) single-pole double-throw switches are designed. A new method that increases fractional bandwidths is introduced. It uses inductively coupled inverters without requiring their tuning. New circuit models are offered for inverters, reconfigurable resonators, and reconfigurable bandstop stubs. Our compact bandpass filter achieved a footprint of only 4.75 mm × 3.75 mm. Measurements for our filters show good agreement with the results of simulations.

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Wu, Qiannan, Honglei Guo, Qiuhui Liu, Guangzhou Zhu, Junqiang Wang, Yonghong Cao i Mengwei Li. "Design and fabrication of a series contact RF MEMS switch with a novel top electrode". Nanotechnology and Precision Engineering 6, nr 1 (1.03.2023): 013006. http://dx.doi.org/10.1063/10.0016903.

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Radio-frequency (RF) micro-electro-mechanical-system (MEMS) switches are widely used in communication devices and test instruments. In this paper, we demonstrate the structural design and optimization of a novel RF MEMS switch with a straight top electrode. The insertion loss, isolation, actuator voltage, and stress distribution of the switch are optimized and explored simultaneously by HFSS and COMSOL software, taking into account both its RF and mechanical properties. Based on the optimized results, a switch was fabricated by a micromachining process compatible with conventional IC processes. The RF performance in the DC to 18 GHz range was measured with a vector network analyzer, showing isolation of more than 21.28 dB over the entire operating frequency range. Moreover, the required actuation voltage was about 9.9 V, and the switching time was approximately 33 μs. A maximum lifetime of 109 switching cycles was obtained. Additionally, the dimension of the sample is 1.8 mm × 1.8 mm × 0.3 mm, which might find application in the current stage.

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Pielka, Michał, Paweł Janik, Małgorzata A. Janik i Zygmunt Wróbel. "Adaptive Data Transmission Algorithm for the System of Inertial Sensors for Hand Movement Acquisition". Sensors 22, nr 24 (15.12.2022): 9866. http://dx.doi.org/10.3390/s22249866.

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Modern systems of intelligent sensors commonly use radio data transmission. Hand movement acquisition with the use of inertial sensors requires the processing and transmission of a relatively large amount of data, which may be associated with a significant load on the network structure. Network traffic limitation, without losing the quality of monitoring parameters from the sensor system, is therefore important for the functioning of the radio network which integrates both the teletransmission sensor system and the data acquisition server. The paper presents a wearable solution for hand movement acquisition, which uses data transmission in the Wi-Fi standard and contains 16 MEMS (Micro Electro Mechanical System) sensors. An adaptive algorithm to control radio data transmission for the sensor system has been proposed. The algorithm implemented in the embedded system controls the change of the frame length, the length of the transmission frame and the frequency of its sending, which reduces the load on the network router. The use of the algorithm makes it possible to reduce the power consumption by the sensor system by up to 19.9% and to limit the number of data transferred by up to about 91.6%, without losing the quality of the monitored signal. The data analysis showed no statistically significant differences (p > 0.05) between the signal reconstructed from the complete data and processed by the algorithm.

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Kamil Naji, Maham, Alaa Desher Farhood i Adnan Hussein Ali. "Novel design and analysis of RF MEMS shunt capacitive switch for radar and satellite communications". Indonesian Journal of Electrical Engineering and Computer Science 15, nr 2 (1.08.2019): 971. http://dx.doi.org/10.11591/ijeecs.v15.i2.pp971-978.

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<span>In this paper, a new type of Radio Frequency Micro-Electro-Mechanical System (RF-MEMS) shunt capacitive switch is designed and studied. RF MEMS switch has a number of advantages in a modern telecommunication system such as low power consumption, easy to fabricate and power handling capacity at radio frequency. At high frequency applications, this switch shows very superior performance due to which it now became one of the key elements for RF application. In this proposed design, an innovative type of MEMS switch is designed. The MEMS switch structure consists of substrate, co-planar waveguide (CPW), dielectric material and a metallic bridge. The proposed MEMS switch has a dimension of 508 µm × 620 µm with a height of 500 µm. The substrate used is GaAs material. The relative permittivity of the substrate is 12.9. This proposed MEMS switch is designed and simulated in both UP (ON) state and DOWN (OFF) state. The proposed RF-MEMS switch is designed and simulated using Ansoft High frequency structure simulator (HFSS) electromagnetic simulator. The simulated result shows better performance parameters such as return loss ( <-10 dB) and insertion loss ( > -0.5 dB) in UP state, whereas return loss ( > -0.5 dB) and isolation (<-10 dB) in DOWN state. This switch has good isolation characteristics of – 43 dB at 27 GHz frequency.</span>

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Al-Amin, Mohammed A., Sufian Yousef, Barry Morris, Hassan Shirvani i Michael Cole. "Development of a double-pole double-throw radio frequency micro electro-mechanical systems switch using an ‘S’ shaped pivot". International Journal of System Assurance Engineering and Management 8, nr 1 (27.07.2016): 173–79. http://dx.doi.org/10.1007/s13198-016-0514-3.

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Potekhina i Wang. "Review of Electrothermal Actuators and Applications". Actuators 8, nr 4 (21.09.2019): 69. http://dx.doi.org/10.3390/act8040069.

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This paper presents a review of electrothermal micro-actuators and applications. Electrothermal micro-actuators have been a significant research interest over the last two decades, and many different designs and applications have been investigated. The electrothermal actuation method offers several advantages when compared with the other types of actuation approaches based on electrostatic and piezoelectric principles. The electrothermal method offers flexibility in the choice of materials, low-cost fabrication, and large displacement capabilities. The three main configurations of electrothermal actuators are discussed: hot-and-cold-arm, chevron, and bimorph types as well as a few other unconventional actuation approaches. Within each type, trends are outlined from the basic concept and design modifications to applications which have been investigated in order to enhance the performance or to overcome the limitations of the previous designs. It provides a grasp of the actuation methodology, design, and fabrication, and the related performance and applications in cell manipulation, micro assembly, and mechanical testing of nanomaterials, Radio Frequency (RF) switches, and optical Micro-Electro-Mechanical Systems (MEMS).

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Ai, Chunpeng, Xiaofeng Zhao, Sen Li, Yi Li, Yinnan Bai i Dianzhong Wen. "Fabrication and Characteristic of a Double Piezoelectric Layer Acceleration Sensor Based on Li-Doped ZnO Thin Film". Micromachines 10, nr 5 (17.05.2019): 331. http://dx.doi.org/10.3390/mi10050331.

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In this paper, a double piezoelectric layer acceleration sensor based on Li-doped ZnO (LZO) thin film is presented. It is constituted by Pt/LZO/Pt/LZO/Pt/Ti functional layers and a Si cantilever beam with a proof mass. The LZO thin films were prepared by radio frequency (RF) magnetron sputtering. The composition, chemical structure, surface morphology, and thickness of the LZO thin film were analyzed. In order to study the effect of double piezoelectric layers on the sensitivity of the acceleration sensor, we designed two structural models (single and double piezoelectric layers) and fabricated them by using micro-electro-mechanical system (MEMS) technology. The test results show that the resonance frequency of the acceleration sensor was 1363 Hz. The sensitivity of the double piezoelectric layer was 33.1 mV/g, which is higher than the 26.1 mV/g of single piezoelectric layer sensitivity, both at a resonance frequency of 1363 Hz.

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Tsai, Shun-Hung, Li-Hsiang Kao, Hung-Yi Lin, Ta-Chun Lin, Yu-Lin Song i Luh-Maan Chang. "A Sensor Fusion Based Nonholonomic Wheeled Mobile Robot for Tracking Control". Sensors 20, nr 24 (9.12.2020): 7055. http://dx.doi.org/10.3390/s20247055.

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In this paper, a detail design procedure of the real-time trajectory tracking for the nonholonomic wheeled mobile robot (NWMR) is proposed. A 9-axis micro electro-mechanical systems (MEMS) inertial measurement unit (IMU) sensor is used to measure the posture of the NWMR, the position information of NWMR and the hand-held device are acquired by global positioning system (GPS) and then transmit via radio frequency (RF) module. In addition, in order to avoid the gimbal lock produced by the posture computation from Euler angles, the quaternion is utilized to compute the posture of the NWMR. Furthermore, the Kalman filter is used to filter out the readout noise of the GPS and calculate the position of NWMR and then track the object. The simulation results show the posture error between the NWMR and the hand-held device can converge to zero after 3.928 seconds for the dynamic tracking. Lastly, the experimental results show the validation and feasibility of the proposed results.

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Gaitzsch, Markus, Steffen Kurth, Sven Voigt, Sven Haas i Thomas Gessner. "Analysis of Au metal–metal contacts in a lateral actuated RF MEMS switch". International Journal of Microwave and Wireless Technologies 6, nr 5 (24.07.2014): 481–86. http://dx.doi.org/10.1017/s1759078714000993.

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This paper reports on the ohmic contacts of an radio-frequency micro-electro-mechanical-system (RF MEMS) switch. The structure of the MEMS is described briefly to give information about the organization of the switch device. The most significant performance data are reported, indicating very low actuation voltage below 5 V, switching time of <10 µs and good RF performance for frequencies up to 5 GHz. Since the contact performance is a key for excellent RF performance in the actuated state and for high reliability as well the article is focused on the contacts. It is supposed that asperities are building the current path in a closed contact, which is proved by measurements of the closing process with high time resolution. The measurements exhibit very good power-handling capabilities of the contacts. The reported findings render prior theoretical experiments with a physical device.

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Zhao, Chen Xu, Xin Guo, Tao Deng, Ling Li i Ze Wen Liu. "Power Handling Capability Improvement of Metal-Contact RF MEMS Switches by Optimized Array Configuration Design of Contact Dimples". Key Engineering Materials 609-610 (kwiecień 2014): 1417–21. http://dx.doi.org/10.4028/www.scientific.net/kem.609-610.1417.

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This paper presents a novel approach to enhancing power-handling capability of metal-contact radio-frequency micro-electro-mechanical systems (RF MEMS) switches based on an Optimized Array Configured (OAC) contact dimples design. The simulation results reveal that this strategy can distribute the RF current more uniformly through each contact of the switch than traditional multiple parallel-configured contacts design, thus leading to a more effective reduction of current through each contact. Therefore, probability of micromelding and adhesion at metal contact point owing to localized high current induced Joule heating, which limits the power handling capability of the metal-contact RF MEMS switch, can be effectively reduced by the proposed approach. Comparing with previously fabricated switch, power-handling capability of the switch with OAC contact dimples can be dramatically improved over 390%.

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Crispoldi, Flavia, Alessio Pantellini, Simone Lavanga, Antonio Nanni, Paolo Romanini, Leonardo Rizzi, Paola Farinelli i Claudio Lanzieri. "Full integrated process to manufacture RF-MEMS and MMICs on GaN/Si substrate". International Journal of Microwave and Wireless Technologies 2, nr 3-4 (7.07.2010): 333–39. http://dx.doi.org/10.1017/s1759078710000474.

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Radio Frequency Micro-Electro-Mechanical System (RF-MEMS) represents a feasible solution to obtain very low power dissipation and insertion loss, very high isolation and linearity switch with respect to “solid state” technologies. In this paper, we demonstrate the full integration of RF-MEMS switches in the GaN-HEMT (Gallium Nitride/High Electron Mobility Transistor) fabrication line to develop RF-MEMS devices and LNA-MMIC (Low Noise Amplifier/Monolithic Microwave Integrated Circuit) prototype simultaneously in the same GaN wafer. In particular, two different coplanar wave (CPW) LNAs and a series of discrete RF-MEMS in ohmic-series and capacitive-shunt configuration have been fabricated. RF-MEMS performances reveal an insertion loss and isolation better than 1 and 15 dB, respectively, in the frequency range 20–50 GHz in the case of pure capacitive shunt switches and in the frequency range 5–35 GHz for the ohmic-series switches. Moreover, the GaN HEMT device shows an Fmax of about 38 GHz and a power density of 6.5 W/mm, while for the best LNA-MMIC we have obtained gain better than 12 dB at 6–10 GHz with a noise figure of circa 4 dB, demonstrating the integration achievability.

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Naito, Yasuyuki, Kunihiko Nakamura i Keisuke Uenishi. "Laterally Movable Triple Electrodes Actuator toward Low Voltage and Fast Response RF-MEMS Switches". Sensors 19, nr 4 (19.02.2019): 864. http://dx.doi.org/10.3390/s19040864.

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A novel actuator toward a low voltage actuation and fast response in RF-MEMS (radio frequency micro-electro-mechanical systems) switches is reported in this paper. The switch is comprised of laterally movable triple electrodes, which are bistable by electrostatic forces applied for not only the on-state, but also the off-state. The bistable triple electrodes enable the implementation of capacitive series and shunt type switches on a single switch, which leads to high isolation in spite of the small gap between the electrodes on the series switch. These features of the actuator are effective for a low voltage and fast response actuation in both the on- and off-state. The structure was designed in RF from a mechanical point of view. The laterally movable electrodes were achieved using a simple, low-cost two-mask process with 2.0 µm thick sputtered aluminum. The characteristics of switching response time and actuation voltage were 5.0 µs and 9.0 V, respectively.

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Shirane, Atsushi, Hiroyuki Ito, Noboru Ishihara i Kazuya Masu. "Planar Solenoidal Inductor in Radio Frequency Micro-Electro-Mechanical Systems Technology for Variable Inductor with Wide Tunable Range and High Quality Factor". Japanese Journal of Applied Physics 51, nr 5S (1.05.2012): 05EE02. http://dx.doi.org/10.7567/jjap.51.05ee02.

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Shirane, Atsushi, Hiroyuki Ito, Noboru Ishihara i Kazuya Masu. "Planar Solenoidal Inductor in Radio Frequency Micro-Electro-Mechanical Systems Technology for Variable Inductor with Wide Tunable Range and High Quality Factor". Japanese Journal of Applied Physics 51 (21.05.2012): 05EE02. http://dx.doi.org/10.1143/jjap.51.05ee02.

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Gaddy, Benjamin E., Angus I. Kingon i Douglas L. Irving. "Effects of alloying and local order in AuNi contacts for Ohmic radio frequency micro electro mechanical systems switches via multi-scale simulation". Journal of Applied Physics 113, nr 20 (28.05.2013): 203510. http://dx.doi.org/10.1063/1.4804954.

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Jin, Jun, Ningdong Hu, Lamin Zhan, Xiaohong Wang, Zenglei Zhang i Hongping Hu. "Design of GHz Mechanical Nanoresonator with High Q-Factor Based on Optomechanical System". Micromachines 13, nr 11 (30.10.2022): 1862. http://dx.doi.org/10.3390/mi13111862.

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Micro-electromechanical systems (MEMS) have dominated the interests of the industry due to its microminiaturization and high frequency for the past few decades. With the rapid development of various radio frequency (RF) systems, such as 5G mobile telecommunications, satellite, and other wireless communication, this research has focused on a high frequency resonator with high quality. However, the resonator based on an inverse piezoelectric effect has met with a bottleneck in high frequency because of the low quality factor. Here, we propose a resonator based on optomechanical interaction (i.e., acoustic-optic coupling). A picosecond laser can excite resonance by radiation pressure. The design idea and the optimization of the resonator are given. Finally, with comprehensive consideration of mechanical losses at room temperature, the resonator can reach a high Q-factor of 1.17 × 104 when operating at 5.69 GHz. This work provides a new concept in the design of NEMS mechanical resonators with a large frequency and high Q-factor.

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Rantakari, P., R. Malmqvist, C. Samuelsson, R. Leblanc, D. Smith, R. Jonsson, W. Simon, J. Saijets, R. Baggen i T. Vähä-Heikkiä. "Wide-band radio frequency micro electro-mechanical systems switches and switching networks using a gallium arsenide monolithic microwave-integrated circuits foundry process technology". IET Microwaves, Antennas & Propagation 5, nr 8 (2011): 948. http://dx.doi.org/10.1049/iet-map.2010.0434.

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Wu, Jing, Xiaofeng Zhao, Chunpeng Ai, Zhipeng Yu i Dianzhong Wen. "The piezoresistive properties research of SiC thin films prepared by RF magnetron sputtering". International Journal of Modern Physics B 33, nr 15 (20.06.2019): 1950152. http://dx.doi.org/10.1142/s0217979219501522.

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To research the piezoresistive properties of SiC thin films, a testing structure consisting of a cantilever beam, SiC thin films piezoresistors and a Cr/Pt electrode is proposed in this paper. The chips of testing structure were fabricated by micro-electro-mechanical system (MEMS) technology on a silicon wafer with [Formula: see text]100[Formula: see text] orientation, in which SiC thin films were deposited by using radio-frequency (13.56 MHz) magnetron sputtering method. The effect of sputtering power, annealing temperature and time on the microstructure and morphology of the SiC thin films were investigated by the X-ray diffraction (XRD) and scanning electron microscopy (SEM). It indicates that a good continuity and uniform particles on the SiC thin film surface can be achieved at sputtering power of 160 W after annealing. To verify the existence of Si–C bonds in the thin films, X-ray photoelectron spectroscopy (XPS) was used. Meanwhile, the piezoresistive properties of SiC thin films piezoresistors were measured using the proposed cantilever beam. The test result shows that it is possible to achieve a gauge factor of 35.1.

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Ai, Chunpeng, Xiaofeng Zhao, Yinan Bai, Yi Li i Dianzhong Wen. "Fabrication and characteristic of force sensor based on piezoelectric effect of Li-doped ZnO thin films". Modern Physics Letters B 32, nr 18 (27.06.2018): 1850208. http://dx.doi.org/10.1142/s0217984918502081.

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In this paper, a force sensor based on piezoelectric effect of Li-doped ZnO (LZO) thin films was presented, which constituted by Pt/LZO/Pt/Ti functional layers and Si cantilever beam. The chips were designed and fabricated by micro electro-mechanical system (MEMS) technology on silicon wafer with [Formula: see text] orientation. In this sandwich structure, the top electrode (TE) was Pt and bottom electrode (BE) was Pt/Ti, LZO piezoelectric thin films were prepared by radio frequency (RF) magnetron sputtering method. The microstructure and morphology were analyzed through X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM), analysis results shows that the LZO thin films with highly c-axis orientation and uniform grain size distribution under sputtering power of 220 W. The experimental results show, when external force loaded on the tip of the beam, the output voltage [Formula: see text] was 280.3 mV at external force of 5 N, the sensitivity of the proposed sensor was 46.1 mV/N in the range of 1–5 N.

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SUGANTHI, S., K. MURUGESAN i S. RAGHAVAN. "OPTIMIZED MECHANICAL DESIGN OF CAPACITIVE MICROMACHINED SWITCH: A CAD-BASED NEURAL MODEL". Journal of Circuits, Systems and Computers 23, nr 03 (marzec 2014): 1450037. http://dx.doi.org/10.1142/s0218126614500376.

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In this paper, the authors propose the neural modeling of optimized design for pull-in instability reduction of micromachined capacitive shunt radio frequency (RF) micro electro mechanical system (MEMS) switch. Prediction of effective dielectric constant and hence the critical collapse voltage that represents the bridge position instability for two typical bridge geometrics have been derived using artificial neural network (ANN). The effects of residual stress, length of center conductor and the gap between the bridge and center conductor of switch in lowering the driving voltage have been studied. Based on the neural model results, we have observed the reduction of 3 V in critical collapse voltage for an increase of 10 μm in length of center conductor. We have also noted the strong variation in voltage (reduction of 0.8 V for 1 MPa residual stress reduction) with respect to residual stress change. We achieved the reduction of 1.5 V in collapse voltage by reducing the gap between the bridge and the center conductor by 0.1 μm. Among the two structures considered, the structure with lower width of the center conductor proved as an optimum in achieving low critical collapse voltage. Further, the performance of trained neural network with the training datasets derived from MATLAB simulation has been evaluated in terms of convergence speed and mean square error.

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Yu, Wen-Ge, Kang-Qu Zhou, Zheng-Zhong Wu, Ting-Hong Yang i Jing Zhao. "Simulation of Novel NEMS Contact Switch Using MRTD with Alterable Steps". Journal of Nanotechnology 2010 (2010): 1–4. http://dx.doi.org/10.1155/2010/492074.

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In order to apply Radio Frequency Micro-nano-Electro-Mechanical System (MEMS/NEMS) technologies to produce miniature, high isolation, low insertion loss, good linear characteristic, and low power consumption microwave switches, we present a novel NEMS switch with nanoscaling in this paper through the analysis of electrics and mechanics of the RF switch. The measured data show the pull-in voltage of 24.1 V and the good RF performance of the insertion loss of below −10 dB at 0 GHz on the “on” state, and the isolation of beyond –40 dB at 0–40 GHz on the “off” state, indicating that the witch is suitable for the 0–40 GHz applications. Our analysis shows that the NEMS switch not only can work in wide frequency bands, but also has better isolation performance in lower frequency, thus extending the application to the lower band. The Haar-wavelet-based multiresolution time domain (MRTD) with compactly supported scaling function is used for modeling and analyzing the nanomachine switch for the first time. The major advantage of the MRTD algorithms is their capability to develop real-time time and space adaptive grids through the efficient thresholding of the wavelet coefficients. The error between the measured and computed results is below 5%, this indicated that the Haar-wavelet-based multiresolution time domain was suitable for simulating the nano-scaling contact switch.

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Wong, Yan Chiew, Tughrul Arslan, Ahmet T. Erdogan i Ahmed O. El‐Rayis. "Efficient ultra‐high‐voltage controller‐based complementary‐metal‐oxide‐semiconductor switched‐capacitor DC–DC converter for radio‐frequency micro‐electro‐mechanical systems switch actuation". IET Circuits, Devices & Systems 7, nr 2 (marzec 2013): 59–73. http://dx.doi.org/10.1049/iet-cds.2012.0327.

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Al-Amin, Mohammed, Sufian Yousef i Barry Morris. "RF MEMS DPDT Switch Using Novel Simulated Seesaw Design". International Symposium on Microelectronics 2013, nr 1 (1.01.2013): 000831–35. http://dx.doi.org/10.4071/isom-2013-thp23.

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This paper investigates an RF MEMS (Radio Frequency Micro Electro-Mechanical System) switch from DC to 5.8 GHz switching, for use in mobile communications systems and devices. The RF MEMS switch uses a novel seesaw design to create a Double-Pole Double-Throw (DPDT) Switch which increases the capabilities of the seesaw design structure. A low Switching supply voltage with high RF isolation was achieved during its development. After looking at other available seesaw designs, it was discovered that an improvement could be attained by adding additional contacts. An improved concept over existing Single-Pole Single-Throw (SPST) seesaw switches was achieved by using a DPDT switch with a set of upper and lower contacts at each side of the seesaw. To conform to the Microscale, from 1 μm – 100 μm, a length of 41μm was chosen to provide an adequate size for fabrication. Copper Bulk General (Cu) was chosen for the pivot material due to its good electrical conductivity and sufficient flexibility for elastic recovery. A working simulation was achieved without compromising the ‘Air-Gap’ between the contacts, which retains high isolation when the switch is open-circuited. The electrostatic supply voltage has been significantly reduced to a value which is closer to that used in mobile devices.

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Iannacci, Jacopo, Giuseppe Resta, Alvise Bagolini, Flavio Giacomozzi, Elena Bochkova, Evgeny Savin, Roman Kirtaev, Alexey Tsarkov i Massimo Donelli. "RF-MEMS Monolithic K and Ka Band Multi-State Phase Shifters as Building Blocks for 5G and Internet of Things (IoT) Applications". Sensors 20, nr 9 (3.05.2020): 2612. http://dx.doi.org/10.3390/s20092612.

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RF-MEMS, i.e., Micro-Electro-Mechanical Systems (MEMS) for Radio Frequency (RF) passive components, exhibit interesting characteristics for the upcoming 5G and Internet of Things (IoT) scenarios, in which reconfigurable broadband and frequency-agile devices, like high-order switching units, tunable filters, multi-state attenuators, and phase shifters will be necessary to enable mm-Wave services, small cells, and advanced beamforming. In particular, satellite communication systems providing high-speed Internet connectivity utilize the K and Ka bands, which offer larger bandwidth compared to lower frequencies. This paper focuses on two design concepts of multi-state phase shifter designed and manufactured in RF-MEMS technology. The networks feature 4 switchable stages (16 states) and are developed for the K and Ka bands. The proposed phase shifters are realized in a surface micromachining RF-MEMS technology and the experimentally measured parameters are compared with Finite Element Method (FEM) multi-physical electromechanical and RF simulations. The simulated phase shifts at both the operating bands fit well the measured value, despite the measured losses (S21) are larger than 5–7 dB if compared to simulations. However, such a non-ideality has a technological motivation that is explained in the paper and that will be fixed in the manufacturing of future devices.

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Rajan V., Prithivi, i Punitha A. "Design and experimental analysis of MEMS-based Ku band phase shifter". Circuit World 44, nr 3 (6.08.2018): 115–24. http://dx.doi.org/10.1108/cw-12-2017-0073.

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Purpose This paper aims to design a radio frequency micro-electro-mechanical system (RF MEMS)-based phase shifter using chamfered coplanar waveguide (CPW) transmission line (t-line) with open-circuit interdigital metal–air–metal (ID MAM) capacitors. Design/methodology/approach The proposed phase shifter achieves maximum differential phase shift with low loss at Ku band. The phase shifter is built with one switchable fixed-fixed beam (MEMS switch) on chamfered CPW t-line in series with two planar open-circuit ID MAM capacitors. An equivalent circuit model for the proposed phase shifter is derived, and its parameters are extracted using an electromagnetic (EM) solver. Findings The MEMS switch is actuated using an electrostatic method with the calculated residual stress of 44.26 MPa. The fabricated phase shifter exhibits low insertion loss, close to 0.14 dB at 17 GHz, with the maximum phase shift of 15.06°. The return loss is greater than 23 dB between 12 and 18 GHz. Originality/value This phase shifter presents a promising solution for low loss applications in the Ku band with a maximum phase shift. As the maximum phase shift of 15.06° is achieved for a unit cell with low insertion loss, the phase shifter is found to be feasible for modern electronically tunable phased arrays used for satellite communication and radar systems.

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Tomic, Slavisa, Marko Beko, Luís M. Camarinha-Matos i Luís Bica Oliveira. "Distributed Localization with Complemented RSS and AOA Measurements: Theory and Methods". Applied Sciences 10, nr 1 (30.12.2019): 272. http://dx.doi.org/10.3390/app10010272.

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Remarkable progress in radio frequency and micro-electro-mechanical systems integrated circuit design over the last two decades has enabled the use of wireless sensor networks with thousands of nodes. It is foreseen that the fifth generation of networks will provide significantly higher bandwidth and faster data rates with potential for interconnecting myriads of heterogeneous devices (sensors, agents, users, machines, and vehicles) into a single network (of nodes), under the notion of Internet of Things. The ability to accurately determine the physical location of each node (stationary or moving) will permit rapid development of new services and enhancement of the entire system. In outdoor environments, this could be achieved by employing global navigation satellite system (GNSS) which offers a worldwide service coverage with good accuracy. However, installing a GNSS receiver on each device in a network with thousands of nodes would be very expensive in addition to energy constraints. Besides, in indoor or obstructed environments (e.g., dense urban areas, forests, and canyons) the functionality of GNSS is limited to non-existing, and alternative methods have to be adopted. Many of the existing alternative solutions are centralized, meaning that there is a sink in the network that gathers all information and executes all required computations. This approach quickly becomes cumbersome as the number of nodes in the network grows, creating bottle-necks near the sink and high computational burden. Therefore, more effective approaches are needed. As such, this work presents a survey (from a signal processing perspective) of existing distributed solutions, amalgamating two radio measurements, received signal strength (RSS) and angle of arrival (AOA), which seem to have a promising partnership. The present article illustrates the theory and offers an overview of existing RSS-AOA distributed solutions, as well as their analysis from both localization accuracy and computational complexity points of view. Finally, the article identifies potential directions for future research.

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Ziaei, A., M. Charles, M. Le Baillif, S. Xavier, A. Caillard i C. S. Cojocaru. "Capacitive and ohmic RF NEMS switches based on vertical carbon nanotubes". International Journal of Microwave and Wireless Technologies 2, nr 5 (październik 2010): 433–40. http://dx.doi.org/10.1017/s1759078710000619.

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The objective is to demonstrate a reproducible carbon nanotube (CNT)-based technology for radio frequency (RF) switch working in the range of 40–60 GHz and fulfilling the specifications: low losses, high isolation, and an operating voltage below 30 V. The first processed component had an operating voltage of 14 V for an ohmic contact in a Nano-Electro Mechanical System (NEMS) tweezer design. This result is confirmed by theory with an operating voltage of 13 V. A capacitive-contact NEMS is also developed using multi-walled CNTs (MWCNTs) coated with a SiO2 dielectric layer deposited by electron beam induced deposition method (EBID). High Frequency Simulation Software (HFSS) RF-simulation on an innovative NEMS geometry shows encouraging results with transmission ratios between “on” state and “off” state up to 34% for ohmic-contact switch and 25% for a capacitive-contact switch.

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Zhang, Yulong, Jianwen Sun, Huiliang Liu i Zewen Liu. "Modeling and Measurement of Thermal–Mechanical-Stress-Creep Effect for RF MEMS Switch Up to 200 °C". Micromachines 13, nr 2 (22.01.2022): 166. http://dx.doi.org/10.3390/mi13020166.

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High-temperature processes, such as packaging and annealing, are challenges for Radio-Frequency Micro-Electro-Mechanical-Systems (RF MEMS) structures, which could lead to device failure. Coefficient of thermal expansion (CTE) mismatch and the material’s creep effect affect the fabrication and performance of the MEMS, especially experiencing the high temperature. In this paper, the Thermal–Mechanical-Stress-Creep (TMSC) effect during thermal processes from room temperature (RT) to 200 °C is modeled and measured, in which an Au-cantilever-based RF MEMS switch is selected as a typical device example. A novel Isolation-Test Method (ITM) is used to measure precise TMSC variation. This method can achieve resolutions of sub-nanometer (0.5 nm) and attofarad (1 aF). There are three stages in the thermal processes, including temperature ramping up, temperature dwelling, and temperature ramping down. In different stages, the thermal–mechanical stress in anchor and cantilever, the grain growth of gold, and the thermal creep compete with each other, which result in the falling down and curling up of the cantilever. These influencing factors are decoupled and discussed in different stages. The focused ion beam (FIB) is used to characterize the change of the gold grain. This study shows the possibility of predicting the deformation of MEMS structures during different high-temperature processes. This model can be extended for material selection and package temperature design of MEMS cantilever in the further studies.

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Miyake, Shojiro, i Mei Wang. "Nano- and Macrotribological Properties of Nanoperiod Multilayer Films Deposited by Bias Sputtering". Journal of Nanotechnology 2012 (2012): 1–16. http://dx.doi.org/10.1155/2012/561250.

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Carbon and boron nitride nanoperiod (C/BN)n, boron nitride and carbon (BN/C)n, carbon nitride and boron nitride nanoperiod (CN/BN)n, and boron nitride and carbon nitride (BN/CN)n ]multilayer films with a 4-nm-period multilayer structure were deposited by bias radio frequency (RF) sputtering. The substrate used for deposition was repeatedly positioned opposite graphite and boron nitride targets. Both the nanoindentation hardness and microwear resistance of the multilayer (CN/BN)n and (BN/CN)n films changed with the layer period. The multilayer films with a 4 nm period had the highest hardness and microwear resistance. The processing characteristics of the (C/BN)n and (BN/C)n films with a 4-nm-period multilayer structure were investigated using a conductive atomic force microscope (AFM) with force modulation, which permits the quantitative recording of current and frictional force as functions of applied force. The results of processing indicated that friction and surface-current measurements are effective methods of investigating multilayer nanostructural surfaces and that the method proposed in this study for micro-electro-mechanical processing systems has high precision.

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Goeke, R. S., R. K. Grubbs, D. Yazzie, A. L. Casias i K. A. Peterson. "Gas Permeation Measurements on Low Temperature Cofired Ceramics". Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2012, CICMT (1.09.2012): 000323–27. http://dx.doi.org/10.4071/cicmt-2012-wa25.

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Commercial low temperature cofired ceramic (LTCC) technology is established in microelectronics and microsystems packaging, multichip and radio frequency (RF) modules, and sensors. The ability to combine structural considerations with embedded traces and components using laminated glass-ceramic tapes has created solutions to unconventional packaging requirements of micro-electro-mechanical systems (MEMS) devices. Many MEMS devices such as resonators are very sensitive to pressure and require packaging in a vacuum environment. Attaining and maintaining desirable pressure levels in sealed vacuum packages requires knowledge of the permeation characteristics of the vacuum envelope and the sealing materials. An experimental system to measure the time dependent gas permeation through LTCC at temperatures from room temperature to 500°C has been developed. This system utilizes a membrane technique in which a gas is allowed to permeate through a test sample, held at a constant temperature, into a high vacuum chamber where it is detected using mass spectrometry. The gas permeation value is determined from the steady state gas flux through the sample. The gas diffusivity and solubility in the material were calculated using data from the time dependent approach to the steady state condition. The gas-solid permeation data for helium through DuPont 951 LTCC is presented and compared to the permeation through other common vacuum envelope materials such as glasses and high-purity alumina ceramics. Application of the permeation data to the prediction of vacuum levels inside typical LTCC packaging is discussed. This data can further be utilized in designs to create LTCC packages that meet specific pressure/time operating requirements.

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Lee, Kibum, i Jinho Kim. "A Novel MEMS Capacitor with a Side Wall for High Tuning Ranges". Applied Sciences 12, nr 21 (26.10.2022): 10858. http://dx.doi.org/10.3390/app122110858.

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These days, the market of wireless communications has developed dramatically. Thus, demand increased with respect to wireless communication terminals that consume less power. Consequently, integration technology for passive elements and circuit module development with respect to ‘Radio frequency systems’ using ‘Micro electro mechanical system’ is becoming a focused topic. Many researchers focused various perspectives in this field. The development of ultra-low operating voltage elements is required in voltage-tunable MEMS-type capacitors, but development for satisfying demands has not occurred. Among many studies, a capacitor with a high tuning range using carrier beams has been proposed by Barki-Kassem and others in 2006. In the proposed study, a high tuning range was generated using a carrier beam when the voltage was applied, passing through the pull-in point and exceeding the controllable range. However, these carrier beams are relatively inefficient because these are applied only in one location and not in several air gaps. Therefore, this study dealt with the optimization of a new MEMS capacitor concept, such as using a total of four beams and by applying a side wall instead of a single carrier beam compared to the previous study. Therefore, in this study, further steps were applied to existing research findings to optimize a new concept MEMS capacitor by applying the side wall instead of a carrier beam. The side wall is the same as the one used in the four-beam example.

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Cetintepe, Cagri, Ebru Sagiroglu Topalli, Simsek Demir, Ozlem Aydin Civi i Tayfun Akin. "A fabrication process based on structural layer formation using Au–Au thermocompression bonding for RF MEMS capacitive switches and their performance". International Journal of Microwave and Wireless Technologies 6, nr 5 (30.07.2014): 473–80. http://dx.doi.org/10.1017/s1759078714000968.

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This paper presents a radio frequency micro-electro-mechanical-systems (RF MEMS) fabrication process based on a stacked structural layer and Au–Au thermocompression bonding, and reports on the performance of a sample RF MEMS switch design implemented with this process. The structural layer consists of 0.1 µm SiO2/0.2 µm SixNy/1 µm Cr–Au layers with a tensile stress less than 50 MPa deposited on a silicon handle wafer. The stacked layer is bonded to a base wafer where the transmission lines and the isolation dielectric of the capacitive switch are patterned. The process flow does not include a sacrificial layer; a recess etched in the base wafer provides the air gap instead. The switches are released by thinning and complete etching of the silicon handle wafer by deep reactive ion etching (DRIE) and tetramethylammonium hydroxide (TMAH) solution, respectively. Millimeter-wave measurements of the fabricated RF MEMS switches demonstrate satisfactory up-state performance with the worst-case return and insertion losses of 13.7 and 0.38 dB, respectively; but the limited isolation at the down-state indicates a systematic problem with these first-generation devices. Optical profile inspections and retrospective electromechanical analyses not only confirm those measurement results; but also identify the problem as the curling of the MEMS bridges along their width, which can be alleviated in the later fabrication runs through proper mechanical design.

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Vallone, Mariangela, Maria Alleri, Filippa Bono i Pietro Catania. "A New Wireless Device for Real-Time Mechanical Impact Evaluation in a Citrus Packing Line". Transactions of the ASABE 63, nr 1 (2020): 1–9. http://dx.doi.org/10.13031/trans.13194.

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Abstract. Postharvest handling of fresh fruit is a potential source of bruising and damage, with significant consequences for fruit quality and marketability. In the last 30 years, different types of impact-recording devices (also called electronic fruits or pseudo-fruits) have been developed with the aim of measuring the impacts experienced by fruits during postharvest operations. The aim of this study was to develop and test a novel wireless instrumented sphere to study the critical points in a citrus packing line by measuring the impacts experienced by fruits in real-time. The non-commercial device was based on a MEMS (micro-electro-mechanical system) sensor node with a sensing range from ±1×g to ±400×g (g = 9.8 m s-2), a ferroelectric RAM (FRAM) memory, a radio frequency (RF) transmitter, a microcontroller, and a 75 mAh lithium battery. The sensor node was placed inside a plastic ellipsoid case with a total weight of 100 g to represent a ‘Tardivo di Ciaculli’ mandarin. An FR receiver allowed real-time transmission of the measured data. Tests were performed in the Consorzio del Mandarino Tardivo di Ciaculli packing line (Palermo, Italy). Total acceleration values, representing the stresses experienced by fruit in the packing line, were studied using a variance component model. The results showed that total acceleration remained below 20×g in most of the measurements, but considerably higher values, up to 80×g, were obtained between the brushing and waxing machines. In particular, waxing was identified as the most critical operation based on the impact transmitted to the fruit. Our system proved to be effective for immediate on-line assessment of the accelerations experienced by fruits, allowing prompt intervention to guarantee fruit quality in postharvest operations.HighlightsA novel, wirelessly instrumented sphere was developed and tested to study the critical points in a fruit packing line.The total acceleration experienced by the fruits was studied using a variance component model.The system was proven effective in online assessment of the accelerations experienced by fruits. Keywords: Acceleration, Damage, Instrumented sphere, Mandarin, Postharvest.

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Zaghloul, Usama, George J. Papaioannou, Bharat Bhushan, Fabio Coccetti, Patrick Pons i Robert Plana. "New insights into reliability of electrostatic capacitive RF MEMS switches". International Journal of Microwave and Wireless Technologies 3, nr 5 (1.09.2011): 571–86. http://dx.doi.org/10.1017/s1759078711000766.

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Among other reliability concerns, the dielectric charging is considered the major failure mechanism which hinders the commercialization of electrostatic capacitive radio frequency micro-electro-mechanical systems (RF MEMS) switches. In this study, Kelvin probe force microscopy (KPFM) surface potential measurements have been employed to study this phenomenon. Several novel KPFM-based characterization methods have been proposed to investigate the charging in bare dielectric films, metal–insulator–metal (MIM) capacitors, and MEMS switches, and the results from these methods have been correlated. The used dielectric material is plasma-enhanced chemical vapor deposition (PECVD) silicon nitride. The SiNx films have been charged by using a biased atomic force microscope (AFM) tip or by electrically stressing MIM capacitors and MEMS switches. The influence of several parameters on the dielectric charging has been studied: dielectric film thickness, deposition conditions, and under layers. Fourier transform infra-red (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) material characterization techniques have been used to determine the chemical bonds and compositions, respectively, of the SiNx films. The data from the physical material characterization have been correlated to the KPFM results. The study provides an accurate understanding of the charging/discharging processes in dielectric films implemented in electrostatic MEMS devices.

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L, Saipriya, Akepati Deekshitha, Shreya Shreya, Shubhika Verma, Swathi C i Manjunatha C. "Advances in Graphene Based MEMS and Nems Devices: Materials, Fabrication, and Applications". ECS Transactions 107, nr 1 (24.04.2022): 10997–1005. http://dx.doi.org/10.1149/10701.10997ecst.

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Microelectromechanical systems (MEMS) are generally known as miniaturized mechanical and electro-mechanical systems, whereas NEMS stands for nanoelectromechanical systems. Graphene is an atomically thin material that features unique properties, such as high carrier mobility, high mechanical strength, and piezoresistive electromechanical transduction, which makes it an extremely promising material for future MEMS and NEMS devices. Design and fabrication of MEMS/NEMS devices using graphene process includes trench etching, wafer backside etching, graphene transfer, and mass release, which are described in a comprehensive manner. This review provides interesting perspectives for lock-in detection of weak fluorescent signals, NEMS position detection, electromechanical control of the on-chip transmitter, and single-photon-level fast electromechanical optical modulation. There are various applications of MEMS/NEMS devices, namely radio frequency devices, optic NEMS, pressure sensors, inertial sensors, which have been discussed in detail. The review mainly focusses on the devices made up of graphene (atom-layer distance of ~0.335 nm) as a main electronic/mechanical material due to its remarkable mechanical and electrical (Young’s modulus of up to ~1 TPa cm2Vs-1) and charge-carrier mobility of up to 200,000, which makes it an extremely promising membrane and transducer material for MEMS/NEMS system applications. Modern MEMS/NEMS experiments utilize mechanical resonators to push the bounds of force and mass sensing, demonstrate novel electromechanical circuit applications, measure the structural properties of materials are also covered in this review.

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Li, Xu i Li. "Analysis of the Performance Variation Mechanism of MEMS Suspended Inductors under Mechanical Shock". Micromachines 10, nr 10 (11.10.2019): 686. http://dx.doi.org/10.3390/mi10100686.

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Micro-electromechanical system (MEMS) suspended inductors have been widely studied in recent decades because of their excellent radio frequency performance. However, the deformation of the inductor coil and the performance variation usually occur to the MEMS suspended inductors when the inductors are under mechanical shock. Few studies have been carried out on the performance variation of MEMS suspended inductors under shock. In this study, the mechanism of the performance variation of MEMS suspended inductors under mechanical shock is analyzed by combining theoretical analysis and experiments. A theoretical analysis based on the lumped-element equivalent model is presented and shock tests are carried out. The shock tests show that the main reason of the MEMS suspended inductor performance variation after mechanical shock is the variation of the substrate parasitic effect, which is caused by the variation of the suspension height of the inductor after shock. The test results agree with the theoretical analysis.

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Zhu, Hongyu, Wenhao Cui, Yanzhang Li i Mingxin Song. "Design and Analysis of a Fluid-Filled RF MEMS Switch". Sensors 23, nr 5 (1.03.2023): 2692. http://dx.doi.org/10.3390/s23052692.

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In the pre sent study, a fluid-filled RF MEMS (Radio Frequency Micro-Electro-Mechanical Systems) switch is proposed and designed. In the analysis of the operating principle of the proposed switch, air, water, glycerol and silicone oil were adopted as filling dielectric to simulate and research the influence of the insulating liquid on the drive voltage, impact velocity, response time, and switching capacity of the RF MEMS switch. The results show that by filling the switch with insulating liquid, the driving voltage can be effectively reduced, while the impact velocity of the upper plate to the lower plate is also reduced. The high dielectric constant of the filling medium leads to a lower switching capacitance ratio, which affects the performance of the switch to some extent. By comparing the threshold voltage, impact velocity, capacitance ratio, and insertion loss of the switch filled with different media with the filling media of air, water, glycerol, and silicone oil, silicone oil was finally selected as the liquid filling medium for the switch. The results show that the threshold voltage is 26.55 V after filling with silicone oil, which is 43% lower under the same air-encapsulated switching conditions. When the trigger voltage is 30.02 V, the response time is 10.12 μs and the impact speed is only 0.35 m/s. The frequency 0–20 GHz switch works well, and the insertion loss is 0.84 dB. To a certain extent, it provides a reference value for the fabrication of RF MEMS switches.

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Ding, Jian Ning, Hui Juan Fan, Li Qiang Guo, Zhen Fan, Guang Gui Cheng, Si Guo Shen i Hua Sheng Pu. "Micro Structures and Mechanical Characters of Hydrogenated Nanocrystalline Silicon Thin Films with Different Doped Proportions". Applied Mechanics and Materials 43 (grudzień 2010): 53–56. http://dx.doi.org/10.4028/www.scientific.net/amm.43.53.

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Hydrogenated nanocrystalline silicon (nc-Si:H) ﬁlms were deposited on glass substrates using Radio frequency plasma-enhanced chemical vapor deposition(RF-PECVD)from a B2H6/SiH4/H2 gas mixtures. In this paper, we mainly changed the Borane-Silane flow rate ratio (β), while other parameters were kept constant. Raman spectrum and X-ray diffraction were employed to investigate the micro-structure of the films, and the indentations were used to measure the mechanical characters (the Young’s modulus (E) and hardness (H)). The Raman spectrum showed that, withβincreasing the crystalline fraction decreased, which indicated that more boron doped might not be propitious to the formation of crystalline of the thin films. XRD spectrum revealed that the films have a remarkably preferential orientation. The analysis of the Young’s modulus and hardness by TriboIndenter nano system suggested that the increase inβhad concernful effects in the decrease of E and H values, so we can control the mechanical characters of the thin films by means of changing the doped concentrations. In view of these results, it may be concluded that the use of lowβconditions might lead to growth of nc-Si:H ﬁlms with high crystallinity, and as well high Young’s modulus and hardness.

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Tang, Tingji, Curt Planje, Ramachandran K. Trichur, Xing-Fu Zhong, Shelly Fowler, Gu Xu, Kimberly Yess, Xie Shao i Daniel J. Vestyck. "Novel Polymeric Protective Coatings for Hydrofluoric Acid Vapor Etching during MEMS Release Etch". Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2010, DPC (1.01.2010): 000942–70. http://dx.doi.org/10.4071/2010dpc-tp24.

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Micro-electro-mechanical system (MEMS) is rapidly becoming a critical part of advanced fabrication technology such as cellular phones, micromirrors, radio frequency (RF) devices, microprobes, and pressure sensors. Release etching of a sacrificial layer of silicon oxide plays an important role in creating the moving parts during these MEMS device fabrication. Traditionally, wet fluorinated etchants have been applied in order to achieve release etching, by which liquid surface tension can cause the MEMS microstructures to stick together (“stiction”) upon removing from aqueous bath or during the drying of released wet-etched structure. It has been demonstrated that using a hydrofluoric acid (HF) vapor release etch can efficiently circumvent stiction phenomena owing to the fact that it substantially eliminates the surface tension that causes the stiction. Conventionally, inorganic based films such as silicon nitride, alumina, SiC, polysilicon, amorphous silicon, and aluminum etc were used as vapor HF etch-resistant mask materials, which require very high temperature and vacuum deposition techniques often lengthy, complicated and costly. Herein, a novel spin-on and polymeric blanket HF-resistant coating material is presented to provide protection of both silicon oxide and aluminum against HF attack during vapor HF etching. Our newly developed polymeric coatings can be processed at lower temperature (<250 °C) and thinner films (less than 10μm) for extended vapor HF etching period (longer than 1 hour). Hence, our vapor HF resistant materials will enable the MEMS industry to significantly lower the cost of manufacturing MEMS devices and will significantly simplify the manufacturing process as well.

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Artykuły w czasopismach na temat „Micro-electro mechanical system - Radio frequency”

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