A New Harmonic Noise Frequency Filtering VCO and Mixer Co-design

An asymmetrical inductance tank (AIT) structure provides high quality factor in tank and harmonic noise frequency filtering (HNFF) technique shorts harmonic noises to ground. The VCO directly drives the on-chipped double balanced mixer to convert RF carrier to IF frequency through local oscillator. Further, output amplifier improves final power performance. This paper presents the design for a prototype 1.721 GHz LC VCO, mixer, and output amplifier that have been designed for low phase noise and high output power. The HNFF-VCO exhibited a phase noise of -133.96 dBc/Hz at 1 MHz offset and a tuning range of 261 MHz. While totally on-chipped downconverter shows a third-order input intercept point (IIP3) of 12.44 dBm, a third-order output intercept point (OIP3) of 21.44 dBm, an input P1dB of 3 dBm, an RF return loss of -31 dB, and an IF return loss of -26 dB. The RF-IF isolation is 57 dB. Also, this downconverter has a conversion gain of 8.9 dB through output amplifier. The totally on-chipped downconverter is 2.56 times 1.07 mm² of chip area