A wide-band RF front-end for multiband multistandard high-linearity low-IF wireless receivers

摘要

A wide-band radio-frequency (RF) front-end is designed with a balanced combined low-noise amplifier and a switching mixer (a low-noise converter) in an RF Si-bipolar process with an fT of 25 GHz. The circuit achieves 20-dB conversion gain, higher than -4.5-dBm RF-to-IF IIP3 (+15.5-dBm OIP3) and less than 3.8-dB double-side-band noise figure in 900-MHz (e.g., GSM) and 1.9-GHz (e.g., WCDMA) frequency bands. The -1-dB compression point is -20 dBm at 13-mA DC current consumption from a single 5-V supply. The local-oscillator leakage to the input is less than -56 dBm in the 900-MHz band and less than -63 dBm in the 1.9-GHz band. The -3-dB bandwidth of the amplifier is larger than 3 GHz and a wide-band matching at the input with -10 to -41-dB S11 is achieved in the frequency bands of interest by applying a dual-loop wide-band active feedback. The die area is 0.69 × 0.9 mm2. The circuit is suitable for area-efficient multiband multistandard low-IF receivers.