A CMOS low power, process/temperature variation tolerant RSSI with an integrated AGC loop

Abstract

A low voltage low power CMOS limiter and received signal strength indicator (RSSI) with an integrated automatic gain control (AGC) loop for a short-distance receiver are implemented in SMIC 0.13 μm CMOS technology. The RSSI has a dynamic range of more than 60 dB and the RSSI linearity error is within ±0.5 dB for an input power from −65 to −8 dBm. The RSSI output voltage is from 0.15 to 1 V and the slope of the curve is 14.17 mV/dB while consuming 1.5 mA (I and Q paths) from a 1.2 V supply. Auto LNA gain mode selection with a combined RSSI function is also presented. Furthermore, with the compensation circuit, the proposed RSSI shows good temperature-independent and good robustness against process variation characteristics.