Development of agile frequency synthesizer

Abstract

Frequency synthesizer consists of a voltage controlled oscillator (VCO) and a Phase-locked loop (PLL). Finer frequency synthesis can be achieved by using a direct digital synthesizer (DDS). The PLL accepts an input of 10MHz which is known as the reference frequency and up converts it to an intermediate frequency of 1 GHz, which acts as an input to the direct digital synthesizer (DDS). The DDS can produce an output ranging from 1 Hz to 400 MHz. Here we are generating a frequency of range 360 ± 5 MHz. The final output frequency of the entire system belongs to C Band of Microwaves which is used in Doppler Weather Radar.