A 130 nm CMOS Passive Mixer Utilizing Positive-Negative Feedback as the Input Transconductance

A. Zokaei, K. El-Sankary (Dalhousie Univ., Canada), D. Trukhachev, A. Amirabadi (Dalhousie Univ., Canada and South Tehran Branch Azad Univ., Iran)

This paper describes the design of a novel passive mixer which utilizes an input Gm stage which enhances the noise performance and also provides a reasonable linearity for the mixer. The mixer is a double balanced passive mixer which utilizes an opamp as the output transimpedance amplifier for the output stage. A class A opamp is designed to ensure the functionality of the circuit and providing the requisite gain at the output stage with a reasonable phase margin. The mixer is simulated in a 130 nm CMOS process. It has a conversion gain of more than 9 dB for more than 4 GHz bandwidth from 1-5 GHz, input referred noise of 2.5 nV/√Hz and dissipates 8.28 mW of power.