A Ka-band 2×2 true-time-delay phased array receiver

This paper presents an integrated Ka-band 2×2 True-Time-Delay (TTD) phased array receiver using a 0.25 nm SiGe:C BiCMOS technology. Each phased array receiver channel is able to perform 20.5 ps variable delay as well as 6 dB variable gain. A mixer and buffer are integrated to down-convert the RF signal into a fixed IF₁ at 11 GHz. Each receiver channel presents more than 20 dB RF-IF₁ conversion gain for a wide input RF frequency range from 25 to 34 GHz. The in-band worst case delay variation is 1.23 ps, i.e. 6% of the total variable delay. Within 25-34 GHz, the measured single channel input P1dB and IIP3 are better than -24 dBm and -16 dBm, respectively. The complete phased array receiver consumes 244 mW power, and has a total chip area of 2.6×2.6 mm².