Bibliografie tematiche / Power amplifiers

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Letteratura scientifica selezionata sul tema "Power amplifiers"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 25 maggio 2024

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Articoli di riviste sul tema "Power amplifiers"

Wang, Haishuo, Tiancheng Yu e Zhe Yang. "Design and output spectral peak power optimization of E-band fiber-amplified spontaneous emission spectra". Highlights in Science, Engineering and Technology 72 (15 dicembre 2023): 624–31. http://dx.doi.org/10.54097/4w1mdt53.

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Fiber optic amplifiers will improve the power of signals propagating in optical fibers, usually using doped ions as amplifiers. The bismuth-doped fiber amplifier can amplify the current E-band signal light, which is less used, and provide a solution to enhance the communication transmission capacity.In this essay, Matlab is used as a research tool, and the bismuth-doped fiber amplifier is selected, and the energy level system is a three-energy levelThe 830 nm-wavelength pumping source amplifies the signal light at 1390 nm. The bismuth-ion velocity and power amplification propagation equations are established, and the amplified spontaneous radiated optical power is calculated. Amplified spontaneous radiation optical power, and through the calculation and simulated annealing algorithm to derive the amplified spontaneous radiation optical power amplification with the doping concentration and fiber length spectrum, in the fiber length of 3.3m and the number of doped particles of 9.1 * 10^25 to obtain the maximum optical power of 7.95*10^-9W.

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Mei, Shangming, Yihua Hu, Hui Xu e Huiqing Wen. "The Class D Audio Power Amplifier: A Review". Electronics 11, n. 19 (9 ottobre 2022): 3244. http://dx.doi.org/10.3390/electronics11193244.

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Class D power amplifiers, one of the most critical devices for application in sound systems, face severe challenges due to the increasing requirement of smartphones, digital television, digital sound, and other terminals. The audio power amplifier has developed from a transistor amplifier to a field-effect tube amplifier, and digital amplifiers have made significant progress in circuit technology, components, and ideological understanding. The stumbling blocks for a successful power amplifier are low power efficiency and a high distortion rate. Therefore, Class D audio amplifiers are becoming necessary for smartphones and terminals due to their power efficiency. However, the switching nature and intrinsic worst linearity of Class D amplifiers compared to linear amplifiers make it hard to dominate the market for high-quality speakers. The breakthrough arrived with the GaN device, which is appropriate for fast-switching and high-power-density power electronics switching elements compared with traditional Si devices, thus, reducing power electronic systems’ weight, power consumption, and cost. GaN devices allow Class D audio amplifiers to have high fidelity and efficiency. This paper analyzes and discusses the topological structure and characteristics and makes a judgment that Class D amplifiers based on GaN amplifiers are the future development direction of audio amplifiers.

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Kharis, Muhamad, Dhidik Prastiyanto e Suryono Suryono. "Perbandingan Efisiensi Daya Penguat Audio Kelas AB dengan Penguat Audio Kelas D untuk Keperluan Sound System Lapangan". Jurnal Teknik Elektro 10, n. 2 (19 dicembre 2018): 54–58. http://dx.doi.org/10.15294/jte.v10i2.11183.

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Class AB audio amplifiers are commonly used but the efficiency is 50%. While the efficiency of class D audio amplifiers is 90% but are rarely used. The purpose of this research is to know how much the power efficiency of field sound system between 1000 watts class AB amplifier and 900 watts class D amplifier. This study is a comparative study that compares different variables with the same sample. The results of power efficiency are obtained from the percentage comparison between the output power and the input power of each audio amplifier. The power efficiency of class D audio amplifiers with IRS D900 type larger than class AB audio amplifiers with Apex B500 type. The efficiency value of class D audio amplifiers at the highest output power reaches 87% while class AB audio amplifiers are only 73%.

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Choi, Ui-Gyu, e Jong-Ryul Yang. "A 120 W Class-E Power Module with an Adaptive Power Combiner for a 6.78 MHz Wireless Power Transfer System". Energies 11, n. 8 (10 agosto 2018): 2083. http://dx.doi.org/10.3390/en11082083.

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In this article, a highly efficient power module is presented with two class-E power amplifiers and an adaptive power combiner for transmitting output powers >100 W at 6.78 MHz in a wireless power transfer system. The losses caused by the combiners and interstage matching circuits or mismatching between the amplifier, and the combiners can significantly reduce the overall efficiency of the power module. To achieve an efficient combination of the output amplifier signals, the adaptive power combiner is proposed based on the consideration of the optimum load impedance characteristics of the power amplifiers. The input impedance of the combiner is designed using series capacitors and resistors between the two input ports of the combiner and the two output signals of the class-E amplifiers at the optimum load condition. The output performances of the proposed module can decrease based on the component mismatch between the two power amplifiers. The proposed power module was implemented on an FR4 PCB, with a 15 mm metal heat sink, and demonstrated an output power of 123.3 W, a power-added efficiency of 85.7%, and a power gain of 25.6 dB at 6.78 MHz. The second harmonic suppression of the module was 37 dBc.

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Choi, Hojong. "Development of a Class-C Power Amplifier with Diode Expander Architecture for Point-of-Care Ultrasound Systems". Micromachines 10, n. 10 (14 ottobre 2019): 697. http://dx.doi.org/10.3390/mi10100697.

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Point-of-care ultrasound systems are widely used in ambulances and emergency rooms. However, the excessive heat generated from ultrasound transmitters has an impact on the implementation of piezoelectric transducer elements and on battery consumption, thereby affecting the system’s sensitivity and resolution. Non-linear power amplifiers, such as class-C amplifiers, could substitute linear power amplifiers, such as class-A amplifiers, which are currently used in point-of-care ultrasound systems. However, class-C power amplifiers generate less output power, resulting in a reduction of system sensitivity. To overcome this issue, we propose a new diode expander architecture dedicated to power amplifiers to reduce the effects of sinusoidal pulses toward the power supply. Thus, the proposed architecture could increase the input pulse amplitudes applied to the main transistors in the power amplifiers, hence increasing the output voltage of such amplifiers. To verify the proposed concept, pulse-echo responses from an ultrasonic transducer were tested with the developed class-C power amplifier using a resistor divider and the designed diode expander architecture. The peak-to-peak amplitude of the echo signals of the ultrasonic transducers when using a class-C power amplifier with a diode expander architecture (2.98 Vp–p) was higher than that for the class-C power amplifier with a resistor divider architecture (2.51 Vp–p). Therefore, the proposed class-C power amplifier with diode expander architecture is a potential candidate for improving the sensitivity performance of piezoelectric transducers for point-of-care ultrasound systems.

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Ismail, Khadijah, P. S. Menon, Sahbudin Shaari, Abang Annuar Ehsan, Norhana Arsad e A. Ashrif A. Bakar. "Link Power Level Improvements in an Amplified 8-Channel CWDM System with Hybrid EDFA-SOA Pre-Amplifier". Applied Mechanics and Materials 799-800 (ottobre 2015): 1361–65. http://dx.doi.org/10.4028/www.scientific.net/amm.799-800.1361.

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The link power improvement in a coarse wavelength division multiplexing (CWDM) system which is transmitted using a hybrid erbium-doped fiber amplifier (EDFA) and semiconductor optical amplifier (SOA) scheme as a pre-amplifier, is discussed. The network is designed for amplifying 8 CWDM channels ranging from 1471 nm to 1611 nm. The hybrid amplifiers’ gain measurement is obtained from experimental work with gain peak at 22 dB which is observed at 1531 nm. The amplifiers also caused power increment of 5.06 dB in the transmission link before the signal is split individually at the receiving end. Based on the higher gain peaks and power spectrum at 1531 nm and 1551 nm wavelengths, the proposed amplified link would be useful for the transmission of video applications.

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Kumar, Sunil, e Arun Kr Chatterjee. "Comparative study of different Sense Amplifiers in 0.18um technology". INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY 7, n. 3 (10 giugno 2013): 615–19. http://dx.doi.org/10.24297/ijct.v7i3.3440.

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A comparative study of different types of sense amplifiers [1] using 0.18um technology is presented. The sense amplifiers under considerations are used in SRAM and DRAM cells.The sensing delay of different types of sense amplifiersÂ are evaluated with respect to variation of bitline capacitance. Comparative results are also provided for the variation in delay with respect to power supply. Extensive results based on 0.18um CMOS technology using CADENCE Spectre simulation tools are presented for different architectures of sense amplifiers. From these results it has been proven that if the output of sense amplifier is isolated from the bitline parasitic capacitance then the sensing delay of sense amplifier reduces.

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Alybin, Vyacheslav, Aleksey Syomochkin, Vladimir Rozhkov e Sergey Avramenko. "Major Items of Construction Amplifiers of UNF Power for the Auxiliary Systems of Spacecrafts". Infocommunications and Radio Technologies 5, n. 1 (25 marzo 2022): 70–78. http://dx.doi.org/10.29039/2587-9936.2022.05.1.05.

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Prospective designs of microwave power amplifiers for on-board equipment of service systems are considered, in which the problem of minimizing the area occupied by them on a thermally stabilized plate of a spacecraft is solved. Microwave power amplifiers provide good heat dissipation and require a degree of redundancy. Each of the amplifiers included in the redundant microwave power amplifier is made on boards located perpendicular to the heat-stabilized plate and fixed on the plate on one or both sides. The area occupied by a duplicated or triple redundant microwave power amplifier does not exceed the area on a thermally stabilized plate required to remove heat from one microwave power amplifier included in its composition. And for a triple redundant microwave power amplifier – the area required for heat removal from two such amplifiers.

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Mbonane, Sandile H., e Viranjay M. Srivastava. "Comparative Parametric Analysis of Class-B Power Amplifier Using BJT, Single-Gate MOSFET, and Double-Gate MOSFET". Materials Science Forum 1053 (17 febbraio 2022): 137–42. http://dx.doi.org/10.4028/p-57edxh.

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This paper presents system performance indices for a class-B power amplifier using Double-Gate (DG) Metal Oxide Semiconductor Field Effect Transistor (MOSFET). It also presents a comparative analysis of three power amplifiers using different switching devices, i.e. Bipolar Junction Transistor (BJT), MOSFET, and DG MOSFET. The MOSFET used in this research work is based on Silicon for n-MOSFET and SiO2 has been used as oxide layer. These power amplifiers are also being designed and simulated to test the speed and time (taken for each of these power amplifiers) to get the output signal when an input signal is applied. A comparison of these three power amplifier circuits is taken in the tabular form to conclude which power amplifier circuit performs better regarding its switching speed and the time. Switching speed relates with the time taken to amplify the signal, which is the same as its time to amplify the signal to a specific gain. Settling time for these three types of power amplifiers have also been tested and presented for the performance of these power amplifiers.

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Murtianta, Budihardja, e Erlina Sari. "Penguat Jembatan dengan Untai Pembalik Fase". Elektrika 14, n. 2 (22 ottobre 2022): 58. http://dx.doi.org/10.26623/elektrika.v14i2.5329.

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The maximum output voltage of the audio amplifier is limited to the magnitude of the power supply voltage of the power transistor or the operational amplifier on the final amplifier. This limits the maximum power of the audio amplifier output. The way to enlarge the output power of the audio amplifier without increasing the voltage is the bridge method or bridged modes. With this method a bridge amplifier will be generated. This Bridge Amplifier is also known as Bridge-Tied Load (BTL) or Bridged Transformerless. The principle of Bridge Amplifiers is to use a pair of final amplifiers whose outputs have opposite phase each other. There are 3 ways to make a pair of power amplifiers have opposing phases: with internal modification, with an audio transformer (phase splitting audio input transformer) and with a simple active phase reversal splitter circuit). This paper will discuss Bridge Amplifiers with simple phase inverting circuits. A pair of audio power amplifiers using two TDA2050 chips which are operated at ± 19 Volt supply voltage. The phase inverting circuit using IC TL072. Sinusoidal signal with an amplitude of 200 mVp and a frequency of 1 KHz is used as an input signal. The results to be observed and measured are gain, input, output and bandwidth of the bridged amplifier compared to the usual amplifier

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Più fonti

Tesi sul tema "Power amplifiers"

Shao, Jin. "Advanced Power Amplifiers Design for Modern Wireless Communication". Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc804973/.

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Modern wireless communication systems use spectrally efficient modulation schemes to reach high data rate transmission. These schemes are generally involved with signals with high peak-to-average power ratio (PAPR). Moreover, the development of next generation wireless communication systems requires the power amplifiers to operate over a wide frequency band or multiple frequency bands to support different applications. These wide-band and multi-band solutions will lead to reductions in both the size and cost of the whole system. This dissertation presents several advanced power amplifier solutions to provide wide-band and multi-band operations with efficiency improvement at power back-offs.

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Lee, Ockgoo. "High efficiency switching CMOS power amplifiers for wireless communications". Diss., Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/37145.

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High-efficiency performance is one of the most important requirements of power amplifiers (PAs) for wireless applications. However, the design of highly efficient CMOS PAs for watt-level applications is a challenging task. This dissertation focuses on the development of the design method for highly efficient CMOS PAs to overcome the fundamental difficulties presented by CMOS technology. In this dissertation, the design method and analysis for a high-power and highefficiency class-E CMOS PA with a fully integrated transformer have been presented. This work is the first effort to set up a comprehensive design methodology for a fully integrated class-E CMOS PA including effects of an integrated transformer, which is very crucial for watt-level power applications. In addition, to improve efficiency of cascode class-E CMOS PAs, a charging acceleration technique is developed. The method accelerates a charging speed to turn off the common-gate device in the off-state, thus reducing the power loss. To demonstrate the proposed cascode class-E PA, a prototype CMOS PA was implemented in a 0.18-μm CMOS process. Measurements show an improvement of approximately 6% in the power added efficiency. The proposed cascode class-E PA structure is suitable for the design of high-efficiency class-E PAs while it reduces the voltage stress across the device.

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Hur, Joonhoi. "A highly linear and efficient out-phasing transmitter for multi-band, multi-mode applications". Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/42823.

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There have been many efforts to improve efficiency of transmitter while meeting stringent linearity requirement of modern communication system. Among the technology to enhance efficiency of linear transmitter, the out-phasing technologies, also called the linear amplification with nonlinear components (LINC), is considered as a promising technology. LINC has been studied long times, since it provides excellent linearity with high efficiency by allowing adopt high efficient switch-mode power amplifiers. However, The LINC transmitter has some technical challenges: linearity degradation due to amplitude and phase mismatches, efficiency degradation due to poor combining efficiency, and narrow frequency bandwidth due to output matching network of switching power amplifier. In this thesis, some state-of-the-art techniques for solving the problems of LINC transmitters are presented. An unbalanced phase calibration technique compensates amplitude/phase mismatches between two parallel paths in the LINC system, and multi-level LINC (MLINC) and an uneven multi-level LINC (UMLINC) structure improve the overall power efficiency. And the reconfigurable Class-D switching PA enables multi-band operation with high efficiency and good linearity. With these techniques, the new multi-band out-phasing transmitter improves the efficiency without sacrificing the linearity performance.

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Bell, Patrick J. "MEMS-reconfigurable microwave power amplifiers". Diss., Connect to online resource, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3219036.

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Mutha, Shashank. "Adaptive Linearization of Power Amplifiers". The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1244049195.

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Al, Tanany Ahmed. "A Study of Switched Mode Power Amplifiers using LDMOS". Thesis, University of Gävle, Department of Technology and Built Environment, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-701.

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This work focuses on different kinds of Switch Mode Power Amplifiers (SMPAs) using LDMOS technologies. It involves a literature study of different SMPA concepts. Choosing the suitable class that achieves the high efficiency was the base stone of this

work. A push-pull class J power amplifier (PA) was designed with an integrated LC resonator inside the package using the bondwires and die capacitances. Analysis and motivation of the chosen class is included. Designing the suitable Input/Output printed circuit board (PCB) external circuits (i.e.; BALUN circuit, Matching network and DC

bias network) was part of the work. This work is done by ADS simulation and showed a simulated result of about 70% drain efficiency for 34 W output power and 16 dB gain at 2.14 GHz. Study of the losses in each part of the design elements is also included.

Another design at lower frequency (i.e.; at 0.94 GHz) was also simulated and compared to the previous design. The drain efficiency was 83% for 32 W output power and 15.4 dB Gain.

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Yousefzadeh, Vahid. "Digitally controlled power converters for RF power amplifiers". Diss., Connect to online resource, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3219220.

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Gray, Blake Raymond. "Design of RF and microwave parametric amplifiers and power upconverters". Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43613.

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The objective of this research is to develop, characterize, and demonstrate novel parametric architectures capable of wideband operation while maintaining high gain and stability. To begin the study, phase-incoherent upconverting parametric amplifiers will be explored by first developing a set of analytical models describing their achievable gain and efficiency. These models will provide a set of design tools to optimize and evaluate prototype circuit boards. The prototype boards will then be used to demonstrate their achievable gain, bandwidth, efficiency, and stability. Further investigation of the analytical models and data collected from the prototype boards will conclude bandwidth and gain limitations and end the investigation into phase-incoherent upconverting parametric amplifiers in lieu of negative-resistance parametric amplifiers. Traditionally, there were two versions of negative-resistance parametric amplifiers available: degenerate and non-degenerate. Both modes of operation are considered single-frequency amplifiers because both the input and output frequencies occur at the source frequency. Degenerate parametric amplifiers offer more power gain than their non-degenerate counterpart and do not require additional circuitry for idler currents. As a result, a phase-coherent degenerate parametric amplifier printed circuit board prototype will be built to investigate achievable gain, bandwidth, and stability. Analytical models will be developed to describe the gain and efficiency of phase-coherent degenerate parametric amplifiers. The presence of a negative resistance suggests the possibility of instability under certain operating conditions, therefore, an in-depth stability study of phase-coherent degenerate parametric amplifiers will be performed. The observation of upconversion gain in phase-coherent degenerate parametric amplifiers will spark investigation into a previously unknown parametric architecture: phase-coherent upconverting parametric amplifiers. Using the phase-coherent degenerate parametric amplifier prototype board, stable phase-coherent upconversion with gain will be demonstrated from the source input frequency to its third harmonic. An analytical model describing the large-signal transducer gain of phase-coherent upconverting parametric amplifiers from the first to the third harmonic of the source input will be derived and validated using the prototype board and simulations.

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Lehtisalo, V. (Ville). "Average power tracking optimization system for LTE power amplifiers". Master's thesis, University of Oulu, 2014. http://jultika.oulu.fi/Record/nbnfioulu-201409171871.

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Abstract. This thesis introduces the design and implementation of an optimization system for average power tracking, used in the RF power amplifier of LTE mobile device. Average power tracking adjusts the supplied voltage of the power amplifier according to output power level so that the linearity of the power amplifier is maintained while the efficiency is improved. The optimization system is implemented with computer controlled measurement equipment setup. The setup consists of an RF signal generator, a power meter and a spectrum analyzer. Performance measurements are performed to the device under test with different bias voltages of the PA and various output power levels, separately for two different power modes of the power amplifier. The performance measurements focus on the ratio of transmission channel power and adjacent channel power. Total efficiency and gain of the device and the current consumption of the power amplifier were also measured. Based on the measurement results, the most suitable voltage for the power amplifier can be selected for each power level with a voltage table optimizing algorithm. The algorithm compares the measured adjacent channel leakage ratio to a predetermined target value and selects the lowest linearity requirements fulfilling a voltage value for the power amplifier. The effects of output power and supplied voltage on the linearity, gain and efficiency of the device are observed. The results show that the performance of the device under test is greatly dependent on the bias voltage of the power amplifier. In addition, the effect of ambient temperature and different frequency channels on the linearity and gain are observed. The measurements show that the temperature affects marginally the gain whereas linearity is more dependent on the used frequency channel. Finally the suitability of the optimized bias voltage table is verified by using it to adjust the power amplifier of a separate test board. The linearity of the product is verified by measuring the adjacent channel leakage ratio and comparing it to official requirements. The voltage table generated with the optimizing algorithm based on the results obtained with the measurement setup is well suited for improving the power amplifier efficiency with average power tracking. It is a fast method to obtain a wide range of measurement results of the performance of a power amplifier with various output power levels and bias voltages.Keskimääräisen tehonseurannan optimointisysteemi LTE-tehovahvistimille. Tiivistelmä. Tässä diplomityössä esitellään LTE-tiedonsiirtotekniikkaa tukevassa matkapuhelimessa käytettävän RF-tehovahvistimen keskimääräisen tehonseurannan optimointisysteemin suunnittelu ja toteutus. Keskimääräinen tehonseuranta säätää tehovahvistimen käyttöjännitettä lähtötehon perusteella niin, että tehovahvistimen lineaarisuus säilytetään ja hyötysuhde paranee. Optimointisysteemi toteutettiin tietokone-ohjatulla mittalaitekokoonpanolla sekä tulostenkäsittelyalgoritmilla. Mittalaitekokoonpano koostuu RF-signaaligeneraattorista, tehomittarista ja spektrianalysaattorista. Testilaitteelle suoritetaan suorituskykymittauksia eri tehovahvistimen jännitearvoilla ja usealla lähtötehotasolla, erikseen kahdelle eri vahvistimen tehotilalle. Suorituskykymittaukset keskittyvät lähetyskanavan sekä viereisen kanavan tehon suhteen mittaukseen. Myös hyötysuhde, kokonaisvahvistus sekä testilaitteen tehovahvistimen virrankulutus mitataan suorituskykymittausten yhteydessä. Mittaustulosten perusteella jännitetaulukon optimointialgoritmilla saadaan valittua sopivin tehovahvistimelle syötettävä jännite kullekin lähtötehotasolle. Algoritmi vertaa viereisen kanavan vuototehon suuruutta asetettuun tavoitearvoon ja valitsee tehovahvistimelle matalimman lineaarisuusvaatimukset täyttävän jännitteen. Havaintoja tehdään testilaitteen tehovahvistimen lineaarisuuden, vahvistuskertoimen ja hyötysuhteen riippuvuudesta lähtötehoon sekä käyttöjännitteeseen. Tuloksista nähdään syötettävän jännitteen vaikuttavan voimakkaasti testilaitteen suorituskykyyn. Myös ympäröivän lämpötilan sekä taajuuskanavan vaikutusta tehovahvistimen lineaarisuuteen ja vahvistuskertoimeen tutkitaan. Mittaukset osoittavat lämpötilan vaikuttavan tehovahvistimen vahvistuskertoimeen marginaalisesti. Sen sijaan lineaarisuuteen vaikuttaa enemmän käytettävä taajuuskanava. Lopuksi optimoidun jännitetaulukon soveltuvuus varmistetaan käyttämällä sitä erillisellä testilevyllä tehovahvistimen jännitteen säätämiseen. Varmistusmittauksissa lineaarisuus testataan mittaamalla viereisen kanavan vuototehon suuruus ja vertaamalla sitä asetettuihin virallisiin vaatimuksiin. Mittalaitekokoonpanolla saatujen mittaustulosten sekä optimointialgoritmin perusteella luotu jännitetaulukko soveltuu hyvin tehovahvistimen hyötysuhteen parantamiseen keskimääräisen tehonseurannan avulla. Se on nopea tapa saada mittaustuloksia tehovahvistimen suorituskyvystä laajalta lähtötehoalueelta eri jännitearvoilla.

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Al-Tahir, Hibah. "Multidimensional Measurements : on RF Power Amplifiers". Thesis, University of Gävle, Department of Technology and Built Environment, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-729.

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Abstract

In this thesis, a measurement system was set to perform comprehensive measurements on RF power amplifiers. Data obtained from the measurements is then processed mathematically to obtain three dimensional graphs of the basic parameters affected or generated by nonlinearities of the amplifier i.e. gain, efficiency and distortion. Using a class AB amplifier as the DUT, two sets of signals – both swept in power level and frequency - were generated to validate the method, a two-tone signal and a WCDMA signal. The three dimensional plot gives a thorough representation of the behavior of the amplifier in any arbitrary range of spectrum and input level. Sweet spots are consequently easy to detect and analyze. The measurement setup can also yield other three dimensional plots of variations of gain, efficiency or distortion versus frequencies and input levels. Moreover, the measurement tool can be used to plot traditional two dimensional plots such as, input versus gain, frequency versus efficiency etc, making the setup a practical tool for RF amplifiers designers.

The test signals were generated by computer then sent to a vector signal generator that generates the actual signals fed to the amplifier. The output of the amplifier is fed to a vector signal analyzer then collected by computer to be handled. MATLAB® was used throughout the entire process.

The distortion considered in the case of the two-tone signals is the third order intermodulation distortion (IM3) whereas Adjacent Channel Power Ratio (ACPR) was considered in the case of WCDMA.

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Più fonti

Libri sul tema "Power amplifiers"

Kazimierczuk, Marian K. RF Power Amplifiers. Chichester, UK: John Wiley & Sons, Ltd, 2014. http://dx.doi.org/10.1002/9781118844373.

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Designing power amplifiers. Indianapolis, IN: Prompt Publications, 1999.

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RF power amplifiers. Chichester, West Sussex, U.K: Wiley, 2008.

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Cordell, Bob. Designing audio power amplifiers. New York: McGraw-Hill, 2011.

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du Preez, Jaco, e Saurabh Sinha. Millimeter-Wave Power Amplifiers. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-62166-1.

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O, Sokal Nathan, a cura di. Switchmode RF power amplifiers. Amsterdam: Elsevier/Newnes, 2007.

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Solar Ruiz, Hector, e Roc Berenguer Pérez. Linear CMOS RF Power Amplifiers. Boston, MA: Springer US, 2014. http://dx.doi.org/10.1007/978-1-4614-8657-2.

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B, Walker John L., a cura di. High-power GaAs FET amplifiers. Boston: Artech House, 1993.

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Amplifiers simplified, with 40 projects. Blue Ridge Summit, PA: TAB Books, 1987.

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RF power amplifiers for wireless communications. Boston: Artech House, 1999.

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Capitoli di libri sul tema "Power amplifiers"

Gift, Stephan J. G., e Brent Maundy. "Power Amplifiers". In Electronic Circuit Design and Application, 333–72. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-46989-4_9.

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Goodge, Malcolm. "Power Amplifiers". In Analog Electronics, 241–64. London: Palgrave Macmillan UK, 1990. http://dx.doi.org/10.1007/978-1-349-20994-1_8.

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Bishop, Graham. "Power Amplifiers". In Audio Circuits and Projects, 61–97. London: Macmillan Education UK, 1985. http://dx.doi.org/10.1007/978-1-349-07404-4_4.

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Waterworth, G. "Power Amplifiers". In Work Out Electronics, 168–89. London: Macmillan Education UK, 1988. http://dx.doi.org/10.1007/978-1-349-10008-8_10.

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Long, Stephen I. "Power Amplifiers". In Communication Electronics: RF Design with Practical Applications using Pathwave/ADS Software, 417–48. New York: River Publishers, 2023. http://dx.doi.org/10.1201/9781032629773-16.

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Klingbeil, Harald, Ulrich Laier e Dieter Lens. "Power Amplifiers". In Particle Acceleration and Detection, 299–325. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-07188-6_6.

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Tietze, Ulrich, Christoph Schenk e Eberhard Gamm. "Power Amplifiers". In Electronic Circuits, 867–84. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-78655-9_15.

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Gregorio, Fernando, Gustavo González, Christian Schmidt e Juan Cousseau. "Power Amplifiers". In Signal Processing Techniques for Power Efficient Wireless Communication Systems, 73–104. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-32437-7_4.

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Yip, Peter C. L. "Power Amplifiers". In High-Frequency Circuit Design and Measurements, 119–38. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-011-6950-9_7.

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Rumsey, Francis, e Tim McCormick. "Power Amplifiers". In Sound and Recording, 371–80. 8^a ed. New York: Routledge, 2021. http://dx.doi.org/10.4324/9781003092919-12.

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Atti di convegni sul tema "Power amplifiers"

Laming, R. I., D. N. Payne, F. Meli, G. Grasso e E. J. Tarbox. "Saturated Erbium-Doped Fibre Amplifiers". In Optical Amplifiers and Their Applications. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oaa.1990.mb3.

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It has not been generally appreciated that the erbium-doped fibre amplifier1 (EDFA) has both a saturation output power which increases with pump power, as well as an ability to operate deep in saturation without signal distortion and interchannel crosstalk2. The latter is a consequence of its slow gain dynamics and is quite different from diode-amplifier behaviour3. Most investigations of the gain-characteristics of EDFAs to date have concentrated on the small input signal regime and attempted to obtain high unsaturated gain for low-pump powers4,5, an attribute which is required for an in-line amplifier. By contrast, in this paper we discuss the application of EDFAs as power (post) amplifiers where the input signal is large and the amplifier saturation behaviour outlined above can be exploited. In the highly-saturated regime we have obtained near-quantum-limited differential pump to signal conversion efficiencies, resulting in 47mW (16.7dBm) of amplified signal for only l00mW of pump power at 978nm. Operating in this mode EDFAs are attractive for application as power amplifiers to ease power budget restrictions in point-to-point digital links, video distribution networks6 and LANs.

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Mehuys, D., D. F. Welch, R. G. Waarts, R. Parke, A. Hardy e W. Streifer. "Modal analysis of monolithically integrated, surface-emitting, master oscillator power amplifiers". In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oam.1990.mk4.

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Recently, promising results have been obtained from a monolithically integrated master-oscillator power amplifier (M-MOPA) composed of a single-mode distributed Bragg-reflector (DBR) oscillator and linear chain of amplifiers and surface-emitting output couplers.1 The oscillator output is successively amplified in index-guided amplifiers and is coupled upwards from the wafer surface via detuned second-order DBR's. Coherent output power from this structure is nearly 0.5 W, in contrast to < 100 mW from coupled arrays of grating-surface-emitting oscillators.

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Koo, Joonhoi, Dong Joon Kim, Seung Won Jun, Hwanseong Jeong, Kwanghyun Lee, Jung Hwan Lee e Minsik Jo. "Narrow Linewidth, Filtered-Superfluorescent High Power Source with Linear Polarization". In Advanced Solid State Lasers. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/assl.2022.jm4a.2.

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We investigate a linearly polarized superfluorescent(SFS) source using a 0.1 nm-filtered ASE of a semiconductor optical amplifier. The SFS source is amplified up to 2 kW by PM-fiberized amplifiers at 1065 nm region.

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Mito, Ikuo, e Kenji Endo. "1.48μm and 0.98μm High-Power Laser Diodes for Erbium-Doped Fiber Amplifiers". In Optical Amplifiers and Their Applications. Washington, D.C.: Optica Publishing Group, 1991. http://dx.doi.org/10.1364/oaa.1991.wc1.

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The development of erbium-doped fiber amplifiers has recently progressed rapidly. Highly efficient power conversion for 1.48μm wavelength pumping enables a post-amplifier to achieve output power greater than 100mW1). When pumped in 0.98μm wavelength, the erbium-doped fiber amplifiers showed very low noise property2), which permits high receiver sensitivity as a pre-amplifier.

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Schuster, Gregory L., e John R. Andrews. "Efficient coherent beam combining of multiple high-power AlGaAs amplifiers". In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/oam.1992.mpp3.

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We are exploring power scale-up of semiconductor lasers through the use of arrays of amplifiers and coherent beam combining. In this paper we report 93%-efficient interferometric beam combining of the output of two saturated amplifiers yielding 372 mW in a single diffraction-limited lobe. A single mode semiconductor laser was amplified in a single stage and divided into two beams of 53 and 71 mW. Each beam was injected into a 10-stripe gain guided amplifier array having dimensions of approximately 100 μm wide by 250 μm long. Each amplifier had antireflective coatings (R~2%) on the front facet and high reflectivity mirrors (R~99%) on the rear facet. The output from the double-pass amplifiers produced 206 mW and 195 mW in the respective central lobes. Relative phase control was implemented by a mirror mounted on a piezoelectric stack before the beams were recombined at a common beam splitter. Proper adjustment of the relative phase resulted in a single beam having an output power of 396 mW with 94% or 372 mW, in a single diffraction-limited lobe. The corresponding single-lobe combining efficiency is 93%. The out-of-phase far-field profile was also recorded and indicated some mode mismatch as well as less than ideal coherence. Based on this data, we have shown that higher saturated gain may be achieved with multi-element systems.

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Auge, J., B. Clesca, B. Biotteau, P. Bousselet, A. Dursin, C. Clergeaud, P. Kretzmeyer et al. "Repeaterless Transmission With 62.9 dB Power Budget Using A Highly Efficient Erbium-Doped Fiber Amplifier Module". In Optical Amplifiers and Their Applications. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oaa.1990.tuc3.

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Laser-diode-pumped erbium-doped fiber amplifiers (EDFA) have recently demonstrated all their potential for very long haul transmissions [1]. In-line EDFA application is clearly identified for long undersea links. However, repeaterless transmissions have many applications, especially over 250 km lengths. Compared to direct detection, heterodyne detection allows to achieve a very high receiver sensitivity, increasing the overall link budget [2], Optical amplifiers highly improve this budget, particularly by compensating for the insertion loss of the external phase modulator in DPSK systems. We report a 565 Mbit/s DPSK transmission experiment at 1.532 μm using an EDFA module at the emission, operating in gain saturation regime. Pumped by laser diodes, this optical post-amplifier delivers an amplified output power exceeding +13 dBm, leading to a repeaterless power budget of 62.9 dB. This gives the potentiality to design over 350 km repeaterless links by use of a pure silica core fiber.

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Way, W. I., A. C. Von Lehman, M. J. Andrejco, M. A. Saifi e C. Lin. "Noise Figure of a Gain-Saturated Erbium-Doped Fiber Amplifier Pumped at 980 nm". In Optical Amplifiers and Their Applications. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oaa.1990.tub3.

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Erbium-doped fiber amplifiers (EDFAs) have recently been extensively studied for applications in long-distance transmission[1] [2] and subscriber loop distribution systems[3][4][5]. The noise figure of the fiber amplifier is a parameter that must be considered in these systems to optimize overall system performance. Noise figures of an EDFA pumped at 1480 nm and 980 nm were reported to be near 5 dB[6], and 3 dB[7], respectively. However, these numbers were measured when the amplifiers were operated in the linear region. An EDFA may be operated in the gain saturation region when it is used as a power amplifier in the subscriber loop[3] [5], or when it is one of the latter stages of many cascaded amplifiers in a transmission system. In the latter case, the amplifier gain saturates because of the accumulated amplified spontaneous emission (ASE) noise, which may be due to the finite passband of interstage optical filters, or because there is not enough inter-stage loss to compensate the amplifier gain. Under the above conditions, questions arise as to whether the amplifier noise figure increases while the gain is saturated, and what are the parameters that control this noise figure degradation. The subject of this paper is to examine these questions.

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Giles, C. Randy. "Signal propagation and noise accumulation in amplified lightwave systems". In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oam.1990.tha4.

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Lightwave systems using optical amplifiers as repeaters offer the advantage of ease of capacity enhancement through the use of either high data rates or wavelength-multiplexed channels. Besides optical fiber nonlinearities, potential limitations of such lightwave systems include the effects of optical amplifier saturation and the accumulation of amplified spontaneous emission. Simulations show that transmission at gigabit-per-second rates over transoceanic distances is possible if erbium-doped fiber amplifiers are used as repeaters. The upper limit on amplifier spacing imposed by noise accumulation is approximately 100 km for a 10000 km, 2.5 Gb/s transmission system. Reduced amplifier spacing lowers the total noise and expands the range of signal powers that satisfy the required signal-to-noise ratio and constraints related to optical-fiber nonlinearities. Best noise performance is obtained with distributed amplification in which the transmission fiber is lightly doped with erbium and optically pumped, so that the gain just compensates the loss. Depending on the supervisory methods, amplified lightwave systems might be operated with regulated optical power or might be free-running, a choice that affects the signal power, efficiency, saturation, and noise figure of the fiber amplifier.

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Mehuys, David G., Ross Parke, Jo S. Major, Steven O'Brien, Robert G. Waarts, Derek Nam e David F. Welch. "High-power coherent semiconductor phased arrays and power amplifiers". In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1991. http://dx.doi.org/10.1364/oam.1991.tugg3.

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Recently, monolithically integrated master oscillator power amplifiers (M-MOPA) have demonstrated >1-W coherent output from a cascade of single-mode amplifiers and grating output couplers.1 By integrating the amplifier and grating output coupler into a single active grating (MAG-MOPA), diffraction-limited coherent output power density up to 1 W/cm has been demonstrated,2 and up to 4 W/cm has been projected. Diffraction-limited emission without active phase control results from the uniformity of traveling wave power along the active grating, which uniformly saturates the carrier density and index of refraction. Furthermore, the uniformly saturated carrier density leads to optimum noise suppression. The characteristics of the surface-emitting MAG-MOPA are compared with high-power edge-emitting antiguide arrays, which have demonstrated up to 1.5 W of diffraction-limited output.3 Finally, preliminary cw operation of both the MAG-MOPA and antiguide technologies show promise.

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Chung, Y. C., J. M. Wiesenfeld, G. Raybon e U. Koren. "Intermodulation Distortion in a Multiple-Quantum-Well Semiconductor Amplifier". In Optical Amplifiers and Their Applications. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oaa.1990.tue5.

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Future wavelength-division-multiplexed (WDM) networks will need an optical power amplifier to boost signal levels. For these applications, multiple-quantum-well (MQW) optical amplifiers are promising due to their inherently larger saturation output powers compared to conventional bulk semiconductor amplifiers [1]. A MQW power amplifier integrated with several tunable lasers has been already demonstrated for the use in future WDM networks [2]. However, a significant limitation on the amplifier performance in these applications is imposed by the intermodulation distortion (IMD) generated by the nonlinear interaction between multiple input signals. When multiple input signals are applied to an amplifier and the channel separations between the signals are less than the reciprocal of the carrier lifetime, the carrier density is modulated at the beat frequency between pairs of input signals. This is the dominant third-order nonlinearity in a semiconductor amplifier [3]. The carrier-density modulation causes gain and refractive index fluctuations at the beat frequency, which, in turn, results in the generation of the intermodulation products. This effect has been extensively studied for the conventional buried heterostructure amplifiers [4]-[5]. However, the IMD in a MQW amplifier can be quite different due to the larger saturation output power and smaller mode confinement factor. In this paper, we report the first measurement of the IMD in a MQW amplifier.

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Rapporti di organizzazioni sul tema "Power amplifiers"

Luhmann, N. C., e Jr. Stable High-Power Harmonic Gyro-Amplifiers. Fort Belvoir, VA: Defense Technical Information Center, settembre 1994. http://dx.doi.org/10.21236/ada293697.

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Rutledge, David. High-Efficiency, Class-E RF Power Amplifiers. Fort Belvoir, VA: Defense Technical Information Center, aprile 2001. http://dx.doi.org/10.21236/ada393787.

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Yu, Charles X., Steven J. Augst, Shawn M. Redmond, Kris C. Goldizen, Daniel V. Murphy, Antonio Sanchez e Tso Y. Fan. Coherent Combining of High-Power Yb Fiber Amplifiers. Fort Belvoir, VA: Defense Technical Information Center, aprile 2011. http://dx.doi.org/10.21236/ada569704.

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Penn, John E. Monolithic Microwave Integrated Circuits (MMIC) Broadband Power Amplifiers. Fort Belvoir, VA: Defense Technical Information Center, dicembre 2012. http://dx.doi.org/10.21236/ada571906.

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Al-kanan, Haider. Power Efficiency Enhancement and Linearization Techniques for Power Amplifiers in Wireless Communications. Portland State University Library, marzo 2020. http://dx.doi.org/10.15760/etd.7287.

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Rodwell, Mark, e Umesh K. Mishra. High Power Broadband Amplifiers for 1-18 GHz Naval Radar. Fort Belvoir, VA: Defense Technical Information Center, giugno 2002. http://dx.doi.org/10.21236/ada403109.

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Ozalas, Matthew T. High Efficiency Class-F MMIC Power Amplifiers at Ku-Band. Fort Belvoir, VA: Defense Technical Information Center, gennaio 2005. http://dx.doi.org/10.21236/ada456277.

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Penn, John E. Monolithic Microwave Integrated Circuits (MMIC) Broadband Power Amplifiers (Part 2). Fort Belvoir, VA: Defense Technical Information Center, luglio 2013. http://dx.doi.org/10.21236/ada585852.

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Elliot McCrory and Robert C. Webber. Analysis of Lifetime Data for the Linac 201 MHz Power Amplifiers. Office of Scientific and Technical Information (OSTI), luglio 2002. http://dx.doi.org/10.2172/796231.

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Nelson, Brian A. ICC Experiment Performance Improvement through Advanced Feedback Controllers for High-Power Low-Cost Switching Power Amplifiers. US: Nelson Scientific Explorations L.L.C., Mountlake Terrace WA, ottobre 2006. http://dx.doi.org/10.2172/893760.

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