Ka-band Vco Design

In a system of Near sensing technique and frequency modulation for measuring distance with millimeter wave , the frequency of the transmitted signal is ruled by the modulating signal, and the distance between the system and target can be calculated by the frequency difference of the transmitted signal and reflected signal. The system will be used in a near distance measurement project. A Voltage-Controlled Oscillator is used to be the transmitting part, which is the key part of the system. The method to design the VCO is described in the paper, and the VCO has been designed to a varactor-tuned Gunn waveguide oscillator. Based on software simulating and the equivalent circuit calculating the VCO has been carried out, and has achieved some goals. Because the linearity of the VCO, which is proportioned to the distance error ratio, is a key parameter of the system, a analogue breakpoint linearizer, to make the system work with a allowed error ratio, is described in the paper.