A K-Band Four-Channel Beamformer with Temperature Compensation Based on 65 nm CMOS Process

This paper presents a K-band four-channel phased array beamformer with temperature compensation in 65 nm CMOS for 5G and satellite communications. The beamformer includes a four-way power divider/combiner, four RF channels, and digital control circuits. Each RF channel comprises a receive chain, a transmit chain, and a pair of receive/transmit (TX/RX) single-pole double-throw (SPDT) switches. The receive chain consists of a low-noise amplifier (LNA), a six-bit reflective-type phase shifter (RTPS), a drive amplifier (DA), two temperature-compensation attenuators (TCAs), and a six-bit attenuator (ATT); the transmit chain integrates a power amplifier (PA), two TCAs, a six-bit RTPS, a DA, and a six-bit ATT. Measurements show the chip exhibits 0–4.5 dB gain, noise figure (NF) 6.5 dBm. In addition, the receive and transmit gain variations are within 0.8 dB and 0.4 dB, respectively, when temperature ranges from −55 °C to 85 °C. With a compact footprint of 3.5 × 4.8 mm2, the beamformer consumes 110 mW (receive) and 190 mW (transmit) DC power per channel.