A 260-MHz RF Bandwidth Mixer-First Receiver With Third-Order Current-Mode Filtering TIA

A mixer-first wideband receiver with RF bandwidth of 260 MHz suitable for the 5G lower frequency band (below 6 GHz) is presented. The filtering trans-impedance amplifier immediately following the mixer is based on a regulated cascode, instead of a conventional shunt-feedback architecture. Thanks to a positive-feedback capacitance multiplication, third-order low-pass filtering in the current domain is performed. Wide bandwidth, high linearity, and low power are thus achieved. Measurements on a 28-nm CMOS chip prototype show alternate channel IIP3 and P1dB of +22 dBm and +3 dBm, respectively. RX NF is 5.5 dB while power consumption is 21.6 mW (signal path) and 7.8-mW/GHz (LO) with 1.8/1.2-V supply.