A High Power-Added-Efficiency Ku-band Frequency Doubler in 28-nm CMOS for Automotive Radar

Changwei Wang, Dongfang Pan, Zongming Duan, Biao Deng, Liguo Sun

Abstract: A 20-40GHz frequency doubler was implemented in 28–nm CMOS technology for automotive radar applications. The frequency doubler consists of a push-push core, an injection-locked core and two balun transformer. The push-push topology with 3-bit digital power control achieves output power control especially when the output power is deteriorated in high temperature condition. Moreover, an insert-locked technique is adopted in the frequency doubler to improve output power by 13dB. The proposed injection-locked technique was implemented by adding adjustable LC resonator which can make up for frequency deviation. By combine these two topologies, this design achieves high conversion gain (CG) of 6.7dB, high fundamental suppression (FS) of 39.9dB and high power added efficiency (PAE) of 8.56%. The chip size is only 0.10 mm 2 excluding PADs.