Analog baseband chain of synthetic aperture radar (SAR) receiver
An analog baseband chain for a synthetic aperture radar receiver implemented in a 130 nm CMOS technology is presented in this paper. Occupying 0.23 mm(2) of silicon area, the baseband chain consists of a three-stage variable gain amplifier (VGA), a 5th-order gm-C low-pass filter (LPF) and an output buffer. The gain of the chain can be controlled by tuning the control voltages of the VGA and has a range from 25 to 34 dB. 8 dB of the gain is embedded into the LPF. The bandwidth of the LPF is programmable from 100 to 190 MHz by means of capacitor matrices. The chain, which uses a 1.2 V supply voltage, achieves an input-referred noise density of 4 nV/ and an in-band IIP3 of -46 dBV rms.
analog baseband chain synthetic aperture radar receiver variable gain amplifier low-pass filter output buffer