A 3 to 6 GHz Highly Linear I-Channel Receiver with over +3.0 dBm In-Band P1dB and 200 MHz Baseband Bandwidth Suitable for 5G Wireless and Cognitive Radio Applications

A highly-linear I-channel receiver prototype is presented for a 3 to 6 GHz broadband radio system with a 200 MHz baseband bandwidth and verified to operate under congested spectrum environments. A direct conversion receiver developed from this prototype is suitable for a cognitive radio, fifth-generation (5G) receiver, and other wireless systems with a total (in-band signal plus blocker) power above -6.0 dBm. The broadband receiver consists of a low-noise transconductance amplifier, a passive mixer, a wideband transimpedance amplifier and a power-efficient minimally-invasive baseband filter. The low-noise transconductance amplifier with high linearity employs a cross-coupled structure and resistive degeneration to achieve low noise and high linearity simultaneously. The common-gate based LNTA achieves 2.3 dB noise figure in simulation. Fabricated in a mainstream 40 nm CMOS technology, the worst-case measured system noise figure is under 5.8 dB at 3 MHz baseband frequency, and the conversion gain is larger than 12.8 dB with passband variations under 2 dB from 1 MHz up to 200 MHz signal bandwidth. Over 3 to 6 GHz, the receiver's in-band IIP3 and input P1db are higher than 15.1 dBm and 3.0 dBm, respectively, whereas the power consumption varies from 64.1 mW to 69.6 mW.