The research presented covers the theory and design of feedback-driven matching networks for radio frequency power amplifiers. The study examines amplifier classifications, types of tunable components, feedback typologies, and control systems to achieve the desired operation. The work centers on designing and implementing a tunable matching network for an amplifier's input and output. The tunable systems provide the amplifier with a wide range of operational frequencies at reasonable power levels comparable to today's modern communication systems and produce millisecond-based tuning times. Simulated results are verified against a fabricated system prototype and tweaked to provide further insight into the design's operation.

Abstract This thesis studies the design methods and properties of supply-modulated switch-mode radio frequency power amplifiers. Besides simulation based studies and theory review, two amplifiers were designed: a discrete MESFET class E amplifier (0.5 W at 1 GHz), and an integrated pHEMT class E-1 amplifier (2.0 W at 1.6 GHz) with an on-chip resonator. The existing design methods of the resonant output network of switching amplifiers were reviewed and some extensions on the handling of nonlinear capacitances were proposed. The effects of varying supply voltage were studied and suggestions were given to minimize Vdd / AM and Vdd / PM distortion in supply modulated amplifiers. The implementation of the bias feed was also discussed resulting in proposing a combination of a short transmission line and a small inductor, which provides both fast supply modulation and little effect on harmonic impedances. The main contributions are related to the study of the input impedance of a class E power amplifier, where the effects of supply dependent input impedance and timing skew generated by injected harmonic distortion were analyzed. The stabilization of the amplifier was also discussed. Based on the findings, a push-pull class E amplifier with extra cross-coupled feedback capacitors and second harmonic traps at the gates appears to be a very good starting point for a further study. / Tiivistelmä Tämä väitöstyö käsittelee radiotaajuuksilla toimivien käyttöjännitemoduloitujen kytkintehovahvistimien ominaisuuksia ja suunnittelumenetelmiä. Suunnittelumenetelmiin liittyvän katsauksen ja simulaatioihin perustuvan tutkimusten lisäksi kaksi vahvistinta toteutettiin väitöstutkimuksen aikana: diskreettikomponentein toteutettu E-luokan vahvistin (MESFET, 0.5 W ja 1 GHz) ja integroituna piirinä toteutettu käänteinen E-luokan vahvistin (pHEMT, 2.0 W ja 1.6 GHz), jonka lähdön resonaattoripiiri sisällytettiin integroituun piiriin. Kytkinvahvistimien suunnittelumenetelmiä verrattiin ja kehitettiin edelleen siten, että suunnitteluvaiheessa voidaan ottaa huomioon esim. transistoripiirin takaisinkytkennässä olevan kapasitanssin epälineaarisuus. Työssä tutkittiin myös käyttöjännitemodulaation vaikutusta kytkinvahvistimien toimintaan, ja tutkimuksen tuloksena annettiin muutamia ehdotuksia käyttöjänniteriippuvan amplitudi- (Vdd / AM) ja vaihemodulaation (Vdd / PM) vähentämiseksi. Lähdön biasointipiirin toteutukseen suositeltiin pienen kelan ja siirtolinjan yhdistelmää. Yhdistelmän avulla pyritään maksimoimaan modulaationopeus ja minimoimaan vaikutukset harmonisiin impedansseihin. Pääkohtina väitöksessä ovat E-luokan kytkinvahvistimesta saadut tutkimus- ja mittaushavainnot käyttöjännitteen funktiona muuttuvasta transistorin tuloimpedanssista sekä suurikokoisen transistorin tuloissa tapahtuvan, säröytymisen aiheuttaman tulosignaalien ajoitusvirheen analyysi. Näiden lisäksi vahvistimen stabiilisuuteen kiinnitettiin huomiota. Saatujen havaintojen perusteella voimme todeta, että push-pull -tyyppinen E-luokan vahvistin olisi mielenkiintoinen valinta jatkotutkimuksille.

Orientador: Carlos Alberto dos Reis Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-12T22:43:50Z (GMT). No. of bitstreams: 1 Thiebaut_MatthieuJacquesAndre_M.pdf: 11116037 bytes, checksum: 353c725fb0cc60a33445209f0ec29a81 (MD5) Previous issue date: 2006 / Resumo: O objetivo deste trabalho é propor uma topologia de receptor adequada para atender as exigências de uma rede de sensores sem fio, onde baixo consumo e baixo custo de fabricação são fundamentais.A topologia escolhida foi a do receptor super-regenerativo realizado em tecnologia CMOS 0,35Km e operando em 900 MHz. O chip foi montado e testado numa placa de alumina junto com alguns componentes passivos externos (circuito tanque e adaptação de impedância) necessários para seu funcionamento. Uma sensibilidade de -82 dBm para uma taxa de erro binário (BER) inferior a 0,1% foi obtida com um sinal modulado tudo-ou-nada (On-Off keying, OOK) de 64 kbits/s. O consumo deste receptor foi de 2,5 mW para uma tensão de alimentação de 2V. / Abstract: The purpose of this work is to develop a radio receiver, which is suitable for application in wireless sensor networks. Among the essential requirements for one such radio are included low power, low cost and high sensitivity. The topology of a super-regenerative receiver to operate in 900MHz was chosen, since it complies with all these requirements in addition to being appropriate for integration. Samples of the developed radio receiver were fabricated in 0,35Km CMOS technology. Prototypes were assembled on alumina plate using a few additional external components as an alternative to evaluate the performance of the radio without being affected by the low quality of the passives L and C used in the tuning block (tank and matching circuit). Test results have shown that the developed receiver features sensitivity of -82 dBm for a bit error rate (BER) lower than 0,1% with an On-Off Keying modulated signal of 64 kbit/s. Measure power consumption has been 2,5 mW for a supply voltage of 2 V. / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica