Design of $X$ -Band RF CMOS Transceiver for FMCW Monopulse Radar

In this paper, an X-band CMOS single chip integrating 16 building blocks is developed for frequency modulation continuous wave radar application. The quadrature and monopulse transceiver consists of a voltage-controlled oscillator, amplifiers, Wilkinson power dividers, 90deg hybrid low-noise amplifiers, rat-race hybrid, a single-pole double-throw switch, an active bandpass filter (BPF), and mixers. The transceiver is fabricated in a standard mixed-signal/RF bulk 0.18-mum CMOS technology with a chip area of 2.6 mm 3.3 mm, including contact pads. The transceiver is implemented by meandered complementary-conducting-strip transmission lines demonstrating their capability of miniaturizing circuits such as 90deg hybrid and rat-race hybrid with 95% and 98% size reduction compared to the prototype designs, respectively. The active BPF consumes 4.5 mW achieving 0-dB insertion loss at the passband. The total power consumption of the transceiver is 0.35 W. Output power of the transmitter is 1 dBm with a 35-dB second harmonic suppression. Moreover, the on-chip isolations between T/R in this compacted transceiver are more than 60 dB. The measured receiver gain and NF are -4.5 and 11.5 dB, respectively. Finally, the obtained in-phase and quadrature signals demonstrate 0.6-dB amplitude and 7deg phase imbalance.