8-GHz, 6.6-mW LC-VCO with Small Die Area and FOM of 204 dBc/Hz at 1-MHz Offset

This letter discusses the design of an 8-GHz LC-tank voltage-controlled oscillator (VCO) for use in a receiver chain developed for the Cerro Chajnantor Atacama Telescope Heterodyne Array Instrument. A VCO-optimization approach is proposed that reduces the phase noise (PN) and minimizes the VCO die area. An LC-VCO is realized in a 0.13- $ {\mu }\text {m}$ CMOS technology to validate the design methodology experimentally. The VCO achieves a worst-case PN, within the whole tuning range of 850 MHz, of -131 dBc/Hz at a 1-MHz offset. At 8 GHz the oscillator PN is measured to be -134.3 dBc/Hz at a 1-MHz offset achieving a figure of merit (FOM) of 204 dBc/Hz.