A 1.9-GHz silicon receiver with monolithic image filtering

A 1.9-GHz fully monolithic silicon superheterodyne receiver front-end is presented; it consists of a low noise amplifier (LNA), a tunable image reject filter, and a Gilbert cell mixer integrated in one die. The receiver was designed to operate with a 1.9-GHz RF and a 2.2-GHz local oscillator (LO) for a 300-MHz IF. Two chip versions were fabricated on two different fabrication runs using a 0.5-μm bipolar technology with 25 GHz transit frequency (f_T). Measured performance for the receiver front-end version 1, packaged and without input matching, was: conversion gain 33.5 dB, noise figure 4.9 dB, input IP3 -28 dBm, image rejection 53 dB (tuned to reject a 2.5-GHz image frequency), and 15.9 mA current consumption at +3 V. The image rejection was tunable from 2.4-2.63 GHz by means of an on-chip varactor. Version 2 had increased mixer degeneration for improved linearity. Its measured performance for the packaged receiver with its input matched to 50 Ω was: conversion gain 24 dB, noise figure 4.8 dB, input IP3 -19 dBm, and 65 dB image rejection for a 2.5-GHz image with an image tuning range from 2.34-2.55 GHz