Ka-band frequency synthesizer involving a varactorless LC-type voltage-controlled oscillator and phase rotation

•The work comprises a varactorless VCO, frequency doubler, and programmable divider.•Channel switching uses a multiphase selection, high-speed programmable divider.•The VCO uses a tunable transformer-base inductor and novel varactorless technique.

This paper discusses the design and fabrication of a high-frequency wide-range frequency synthesizer based on a phase locked loop (PLL), varactorless LC-type voltage-controlled oscillator, and push–push frequency doubler. In addition, a high-speed programmable divider using multiphase selection is employed for channel switching. The proposed circuits were fabricated in a standard 90-nm CMOS process with a chip area of 0.8 mm×1.1 mm. The PLL dissipated 60 mW when the supply was 1.2 V. The measured phase noise of the frequency synthesizer at a frequency of 17.64 GHz and offset of 1 MHz was −97 dBc/Hz.