Fabrication of Hyperabrupt GaAs Varactor Diode for W-band Waveguide VCO

In this work, we fabricated a hyperabrupt varactor diode and W-band waveguide VCO using fabricated varactor diode. With the anode diameter of 90 pm, a maximum reverse breakdown voltage of 40 V at a leakage current of 30 RA, a maximum capacitance of 5.82 pF, and a minimum capacitance of 0.7 pF were obtained, resulting in a C(max)/C(min), ratio of 8.31. Fabricated VCO showed an excellent linearity of 1.6 % within 800 MHz. The bandwidth of the VCO was 1.165 GHz from 93.305 GHz to 94.47 GHz, and the output power was from 14.6 dBm to 15.42 dBm.