A CMOS low-power variable-gain amplifier with RSSI for a noncoherent low data rate IR-UWB receiver

A low-power variable-gain amplifier (VGA) with integrated received signal strength indicator (RSSI) for a low data-rate impulse radio ultra-wideband (IR-UWB) receiver is designed and implemented in a CMOS 0.18 ¿m technology. The VGA achieves a gain range from -9 dB to 63 dB and bandwidth from 31 to 187 MHz. An input P1dB of -15.4 dBm is achieved at zero-dB gain. The RSSI has a dynamic range more than 70 dB. The RSSI linearity error is within ±1.2 dB for an input power from -77.5 dBm to -36.2 dBm. The VGA with integrated RSSI draws 5.4 mA from a 1.8 V single supply and the test chip occupies an area of 970 ¿m × 750 ¿m, including two huge output buffers and digital gain control circuit.