A Ku-band dual control path frequency synthesizer using varactorless Q-enhanced LC-type VCO

Abstract

This study focused on the design principle and implementation of a high-frequency, wide-range frequency synthesizer by using a dual control path phase-lock loop (PLL) and a varactorless oscillator controlled by inductive–capacitive (LC-type) voltage (i.e., a voltage-controlled oscillator, VCO). Without a varactor in the LC tank, the tuned-transducer oscillator with Q-enhanced functionality can easily arrive at the requirements of high-frequency wide-range low-noise operations. We utilized a difference tuned varactorless VCO to create two different KVCOs and applied it to a dual control path PLL architecture to obtain wide tuning range and more favorable phase noise. In addition, a high-speed current-mode logic divider was employed given its high speed (because of the use of a transformer inductor), extremely high operation frequency, and wide-range. The proposed PLL was assembled using the standard 0.13-μm CMOS technology on a 0.95 × 1.05 mm2 chip. The PLL dissipated 40 mW at a 1.2 V supply. The measurement of phase noise at 17.64 GHz was − 98.12 dBc/Hz at a 1 MHz offset.