Umudike Journal of Engineering and Technology

Michael Okpara University of Agriculture, Umudike


INVESTIGATION OF THE EFFECT OF NON-FOSTER MATCHING ON THE PERFORMANCE OF CLASS B AND CLASS-J GAN HEMT POWER AMPLIFIERS

Akwuruoha, C. N.
Department of Electrical/Electronic Engineering, Michael Okpara University of Agriculture Umudike, Nigeria

Agwu, O. E.
Department of Electrical/Electronic Engineering, Michael Okpara University of Agriculture Umudike, Nigeria

Amadi, C. C.
Department of Computer Engineering, Michael Okpara University of Agriculture Umudike, Nigeria



ABSTRACT

This paper investigates effect of non-Foster matching on the performance of Class B and Class-J GaN HEMT (Gallium Nitride High Electron Mobility Transistor) power amplifiers. The performance of Class B and Class-J Power Amplifiers (Pas) with and without Non-Foster Circuit (NFC) in terms of efficiency, output power and power gain are investigated and compared. The PAs were designed based on Cree’s CGHV40030F GaN HEMT. The Class B PA was biased at cut-off (drain supply voltage of 40 V and gate voltage of -3.2 V at quiescent drain-to-source current of 0 A. The Class-J PA was biased with drain supply voltage of 40 V at quiescent drain-to-source current (IDSq) of 35 mA. The PAs operate from 4.15 to 4.55 GHz with center frequency of 4.35 GHz. The NFC has effective negative capacitance of -0.96 pF at 4.35 GHz center frequency.  Simulation results indicates that at input power of 32 dBm, Class B PA with NFC has 46 % drain efficiency, 41.6 % PAE, 42.1 dBm (16.2 W) output power and 10.1 dB transducer power gain whereas the Class B PA without NFC has 33.4% drain efficiency, 29.9% PAE, 38.9 dBm (7.8 W) output power and 6.9 dB transducer power. Class-J PA with NFC has 45.4% drain efficiency, 42.5% PAE, 42.5 dBm (17.8 W) output power and power gain of 10.5 dB whereas Class-J PA without NFC has 38.6% drain efficiency, 33.6% PAE, 40.4 dBm (11 W) output power and power gain of 8.4 dB.


Keywords: Class J, Class B, non-Foster, negative capacitance, parasitic capacitance, power amplifier


https://doi.org/10.33922/j.ujet_v7i2_2
View: 95 | Download: 9

Published
Tuesday, February 15, 2022

Issue
Vol. 7 No. 2, Dec. 2021

Article Section
GENERAL

The contents of the articles are the sole opinion of the author(s) and not of UJET.


Open Access
Umudike Journal of Engineering and Technology makes abstracts and full texts of all articles published freely available to everyone immediately after publication thereby enabling the accessibility of research articles by the global community without hindrance through the internet.

Indexing and Abstracting
We are index in Google Scholar, AJOL, and EBSCO.