30-MHz pojačalo u klasi E sa AlGaN/GaN HFET-om

master's thesis

• Title (english): 100W 30-MHz Class E RF amplifier with AlGaN/GaN HFET-om
• Author: Tomislav Majdak
• Mentor: Dubravko Babić (mentor)
• Committee member: Dubravko Babić (predsjednik povjerenstva)
• Committee member: Juraj Bartolić (član povjerenstva)
• Committee member: Zvonimir Šipuš (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2018-07-05, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering

Abstract

Pojačala klase E su visokoefikasna pojačala koja koriste tranzistor kao sklopku te prilagodnu mrežu koja oblikuje valne oblike napona i struje s ciljem smanjivanja disipacije na tranzistoru. Na taj način povećavamo ukupnu efikasnost pojačala. Klasa E pojačala je razvijena 1975. godine od strane Nathana O. Sokala. Glavna ideja E klase pojačala je ispravljanje nedostataka D klase pojačala, gdje izlazni kapacitet tranzistora pri višim frekvencijama povećava disipaciju, a samim time smanjuje ukupnu efikasnost pojačala. Cilj ovog diplomskog rada je bio dizajnirati pojačalo izlazne snage 100 W na frekvenciji od 30 MHz korištenjem GaN HFET tranzistora. GaN HFET tranzistori za razliku od silicijskih tranzistora posjeduju puno bolje karakteristike koje nam mogu pomoći pri povećanju efikasnosti. Bitni parametri su: ulazni kapacitet, izlazni kapacitet, dinamički otpor, manje dimenzije tranzistora, cijena. Tranzistor kojeg smo koristili jest GS66508T (GaN-Systems). Pri dizajniranju pojačala poslužili smo se simulacijskim alatima LTspice i ADS. Tiskanu pločicu dizajnirali smo pomoću programskog alata Altium Designer. Nakon mjerenja karakteristika pojačala ustanovili smo kako se podaci nisu podudarali s rezultatima simulacija.

Abstract (english)

Class E power amplifers are high efficiency amplifiers that use transistors as an on-off switch and an impedance matching network that shapes current and voltage waveforms to increase overall efficiency. Class E power amplifiers were developed in 1975. by Nathan O. Sokal. The main idea behind class E power amplifers is to correct the disandvanteges of the class D power amplifiers, where the output capacitance of the transistor at higher frequency increases dissipation and thereby reduces the overall efficiency of the amplifier. The main goal of this thesis was to design a 100 W, 30MHz class E power amplifier using a GaN HFET transistor. GaN HFET transistors, unlike silicon transistors, possess much better characteristics which can help us to increase overall efficiency of the amplifier. The essential parameters in which the GaN HFET transistors are much better than silicon transistors are: input capacitance, output capacitance, dynamic resistance, smaller dimensions and lower price. The transistor we used is GS66508T (GaN-Systems). When designing the class E power amplifier, we used simulation tools such as LTspice and ADS. We also have used Altium Designer to design a printed circuit board. After we measured the amplifier characteristics, we found that the data did not match the simulation results.

• Keywords: E klasa pojačala; sklopka; GaN HFET tranzistor; prilagodna mreža; LTspice; ADS
• Keywords (english): Class E power amplifiers; switch; GaN HFET transistor; impedance matching network; LTspice; ADS
• Language: croatian
• URN:NBN: urn:nbn:hr:168:300279
• Study programme: Title: Electrical Engineering and Information Technology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka elektrotehnike i informacijske tehnologije (magistar/magistra inženjer/inženjerka elektrotehnike i informacijske tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-03-13 22:29:18