A Fully Integrated K-Band Dual Down-Conversion Receiver for Radar Applications in 90 nm CMOS

• Published in: IEEE access 2020, Vol.8, p.19576-19589
• Main Authors: Li, An'an, Ding, Yingtao, Song, Zheng, Chen, Zipeng, Sun, Shiyan, Li, Yutian, Wu, Yinghang, Wang, Zhenwu, Chen, Zhiming, Lin, Min, Chi, Baoyong
• Format: Article
• Language: English
• Subjects: Automatic control; Automatic gain control; automatic gain control loop (AGC); band-pass filter; Bandwidths; Broadband; Charge pumps; CMOS; Compensation; Conversion; Dual-conversion receiver; Frequency synthesizers; Gain; Gain control; Image filters; image rejection filter; Intermediate frequencies; Low noise; Millimeter waves; Mixers; Noise levels; Noise measurement; Operational amplifiers; Phase locked loops; Phase locked systems; Phased arrays; Radar applications; Radar arrays; Radio frequency; RC circuits; Receivers; Rejection; Synthesizers; Variable gain; wireless receiver
• ISSN: 2169-3536; 2169-3536
• DOI: 10.1109/ACCESS.2020.2968512

A fully integrated K-band dual down-conversion receiver for phased array radar applications in 90 nm CMOS is presented. The receiver utilizes the dual down-conversion architecture to achieve superior performance. The integrated 1.15 GHz image-rejection filter (IRF) provides enough wideband (22 MHz) image rejection ratio at 140 MHz offset before the second down-conversion by utilizing the Q-enhancing and frequency staggering techniques to compensate the component loss. The low noise amplifier realizes the single-to-differential-ended conversion at the input with a transformer and achieves good common-mode rejection. The 70 MHz intermediate frequency baseband consists of two cascaded 3rd-order band-pass active RC filters (BPFs) and one automatic gain control (AGC) loop, with the integrator frequency compensation technique to lower down the requirements on the embedded Op-Amps. Two phase-locked loop (PLL) frequency synthesizers are integrated to provide the local oscillation (LO) signals for the down-conversions, where the matching of the charge-pump is improved by adding one extra current compensation branch. The measurements of the prototype show that the receiver converts the targeted mm-wave signal to 70 MHz intermediate frequency while achieving 8.3 dB noise figure (NF), 51-95 dB variable gain range and >45 dB image rejection ratio at 140 MHz offset with >22 MHz signal bandwidth. The receiver draws 74 mA current (excluding 2 PLLs) from the 1.2 V power supplies and occupies a core area of 4.58 × 0.53mm 2 (excluding 2 PLLs).