Equal-gain loci and stability of a microwave GaAs MESFET gate mixer

Author

Shimizu, Masahiko ; Daido, Yoshimasa

Author_Institution

Fujitsu Lab. Ltd., Kawasaki, Japan

Volume

39

Issue

1

fYear

1991

fDate

1/1/1991 12:00:00 AM

Firstpage

140

Lastpage

142

Abstract

The performance of a microwave GaAs MESFET gate mixer is theoretically investigated to clarify the existence of a conditionally stable RF frequency range as well as an unconditionally stable frequency range in which maximum available conversion gain (MACG) can be defined. For the unconditionally stable range, the MACG and load and source impedances are calculated as functions of RF frequency. For the conditionally stable range, the stability circle and equal gain loci are shown for source RF and load IF impedances. The conditionally stable region of the GaAs MESFET mixer appears around F_T of the MESFET. Higher conversion gain is easily obtained by choosing a MESFET for which the F_T is close to the RF frequency

Keywords

III-V semiconductors; Schottky gate field effect transistors; gallium arsenide; mixers (circuits); solid-state microwave circuits; stability; GaAs; MACG; MESFET gate mixer; conditionally stable RF frequency range; equal gain loci; functions of RF frequency; load impedances; maximum available conversion gain; semiconductors; source impedances; stability; stability circle; unconditionally stable frequency range; Circuit noise; Circuit stability; Frequency conversion; Gallium arsenide; Impedance; MESFETs; Mixers; Radio frequency; Scattering; Sparse matrices;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/22.64618

Filename

64618