An 18dBm transmitter frontend with 29% PAE for 24GHz FMCW radar applications

A CMOS transmitter frontend integrated circuit suitable for 24-GHz frequency-modulated continuous-wave (FMCW) radar applications is presented in this paper. With a transformer-based power-combining technique and pseudo-differential class-AB power amplifiers (PAs), the proposed circuit exhibits enhanced output power and efficiency at a nominal supply voltage. In addition, a voltage-controlled oscillator is incorporated for frequency modulation purposes while differential amplifiers are utilized as the driver stages for the PAs to facilitate near-saturation circuit operation. The transmitter frontend is fabricated in a 65-nm CMOS process, demonstrating an output power of 18 dBm and a power-added efficiency (PAE) of 29% at 1.2-V supply voltage.