Phase noise of the broadband microwave voltage controlled oscillator with tuning characteristic linearized by the diode converter

Abstract

The application of the voltage converter for the broadband microwave voltage controlled oscillator (VCO) is considered in this paper. Special attention is paid to additional phase noises of VCO by called use of the diode voltage converter. Studies showed, that at analysis frequencies more than 10 kHz additional phase noise spectral density can be reduced due to decrease of the converter load resistor value. On low analysis frequencies (less than 1 kHz) reduction of diodes number, used in converter, decreases an additional phase noise. For reduction of a phase noise at these frequencies it is necessary to use diodes with the low level of the flicker noise. It is shown, that when using low-noise detector diodes, the level of additional phase noises can be less than −10 dB/Hz at 10 Hz offset from the carrier frequency and less than −110 dB/Hz at the analyzed frequency equal to 100 kHz.