Design of low power low phase noise negative resistance Ku‐band VCO using planar resonator pair

Abstract

ABSTRACTNew negative resistance voltage‐controlled oscillator (VCO) at Ku‐band is designed. The proposed topology uses packaged NPN Silicon Germanium RF transistor and two parallel resonator structures connected to the device emitters. Novel active open ended planar structure is proposed as a resonator for the VCO. Resonator is analyzed in terms of required reflection coefficient and input impedance. Resonator's quality factor varies in between 159 and 235 as a function of tuning voltage. VCO microwave IC is fabricated on TMM10i soft substrate with 17.5μm Cr‐Cu‐Au metallization process. VCO can be tuned for 180MHz by varying resonators’ varactors from 0 to 22 V. Measured output power remains in between 4.2 and 8.06 dBm for the entire tuning range. Measured phase noise is −145 dBc/Hz at 1 MHz offset with 8 V tuning voltage. Normalized phase noise figure of merit for the VCO is −214.4 dBc/Hz. The circuit has low power consumption of 25.5 mW and high DC to RF conversion efficiency (ηDC‐RF). © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1938–1941, 2015