Title :
Analysis of conversion gain in a bipolar Gilbert cell microwave mixer
Author :
Pallier, Christine ; Algani, Catherine ; Alquie, Georges
Author_Institution :
ENSEA-EMO, Cergy-Pontoise, France
Abstract :
This work presents a theoretical study of conversion gain in a bipolar Gilbert cell mixer. This double-balanced structure can function at microwave frequencies with the use of HBTs. In order to optimise conversion gain of such mixers, the influence of each transistor non-linearity has been investigated. A simplified model based on transistor equivalent circuit and the conversion matrix method has been used to derive analytical expressions of Gc versus RF input frequency. In case of a down-converter function the main non-linearity which contributes to conversion gain is the transconductance non-linearity and the expressions demonstrate ten typical frequencies introduced by base-emitter and base-collector capacitances
Keywords :
capacitance; equivalent circuits; heterojunction bipolar transistors; microwave mixers; semiconductor device models; HBTs; RF input frequency; base-collector capacitance; base-emitter capacitance; bipolar Gilbert cell microwave mixer; conversion gain; conversion matrix method; double-balanced structure; down-converter function; transconductance nonlinearity; transistor equivalent circuit model; transistor nonlinearity; Capacitance; Circuit analysis; Equivalent circuits; Frequency conversion; Heterojunction bipolar transistors; Microwave transistors; Mixers; Power system reliability; Radio frequency; Transconductance;
Conference_Titel :
High Frequency Postgraduate Student Colloquium, 1997
Conference_Location :
Leeds
Print_ISBN :
0-7803-3951-7
DOI :
10.1109/HFPSC.1997.651670
