A 57.5-90.1-GHz magnetically tuned multimode CMOS VCO

This paper presents a magnetically tuned (MT) multimode VCO featuring an ultrawide frequency tuning range. A switched-triple-shielded transformer is proposed to change the magnetic coupling coefficient between the primary and secondary coils in the transformer tank to greatly increase the frequency tuning range of the dual-band VCO to cover the whole E-band continuously. Fabricated in a 65-nm CMOS process, the MT-VCO measures a frequency tuning range of 41.1% from 57.5 to 90.1 GHz while consuming 7 to 9 mA at 1.2-V supply with chip area of 0.03 mm². The measured phase noises at 10-MHz offset from carrier frequencies of 58, 72.2, 80.5, and 90.1 GHz, are -107.4, -111.8, -107.8, and -105.1 dBc/Hz, respectively, which correspond to FOM_T between - 184.2 and - 192.2 dBc/Hz.