A Reconfigurable Injection-Locked LO Generator With a Wideband-Harmonic-Shaping Class-F23 VCO for Multibands 5G mm-Wave

A reconfigurable injection-locked local oscillator (RE-ILO) generator that leverages a multitanks wideband-harmonic-shaping Class-F23 voltage-controlled oscillator (VCO), a RE injection-locked frequency multiplier (RE-ILFM), and a power-efficient injection-locked frequency amplifier (ILFA) for multiple fifth-generation (5G) millimeter-wave (mm-wave) bands is hereby presented. For the VCO, an inductive multiplier inside the positive feedback loop boosts the drain-to-gate voltage gain (Av). Besides, a source-inductive loaded on the output buffer, coupled with a separated inductor, is feedback to the drain of the cross-coupled transistors to expand the impedance peak at the 3rd harmonic for a small fluctuation of 1/
$f^{3}$
phase noise (PN) corner over the entire tuning range (TR). The measured results of the VCO prototype in 55-nm CMOS achieved the VCO measures a TR of 10.65–14.37 GHz, i.e., 29.74%. The FOM
$_{T}$
is 192.2 dBc/Hz and the 1/
$f^{3}$
PN corner is 380 ± 100 kHz. Additionally, a RE-ILFM with both frequency
$\times 2$
doubler mode (DM) and
$\times 3$
tripler mode (TM) is introduced to expand the operation band of the VCO. The ILFA is cascaded for harmonic rejection and power improvement. The proposed RE-ILO generator achieves a frequency TR from 22.25 to 28.61 GHz, i.e., 25% and 35.9–42.04 GHz, i.e., 15.75% with a 1-MHz-offset PN from −102.78 to −104.1 dBc/Hz at DM, −98.48 to −100.67 dBc/Hz at TM, and consumes 66 mW power with an output power of 1.3 dBm.