Research Of New Phase Modulator Based On Reflecting Modulation

Micro-Union system is mainly used in telemetry, command and ranging(TCR) system of satellites and spacecrafts. The transponder is the key unit of the unified measurement and control system, the most important function is obtaining and demodulating the remote control signals from ground stations, the transponder can forwards measurement signal of range and velocity, measures tracks and sends all kinds of telemetry data from the aircraft to the ground station, realizes telemetry function and generates a stable continuous wave signal, becomes round station guidance beacon. Phase modulator is an important circuits in the transmit channel of transponder, and its performance directly affects the indicator of transponder and telemetry channel.According to the task requirements, this thesis researchs extensively phase shifter circuit, through the extensive investigation of the components used in the circuit, designs and simulates condenser, modulates the phase of reflective phase modulator, temperature compensation for the phase shifter is finished by thermistor network, reducing modulation degree of variation in a wide range of temperature. Subsequently, processing and production of the circuit board will be in progress, and a series of experiments will be carried out. Finally, we can develop a phase shifter circuit with high reliability that adapt to a wide range of temperature(-35 ~ +70), easy to debug and test.This thesis reviews the development of satellite transponder in condenser technology and application status at home and abroad, sketchs out the working principle of phase modulator and its peripheral circuit. And then introduces in detail design scheme of phase modulator based on reflection, obtains the result of Advanced Design System(ADS) circuit envelope simulation, finally elaborates the development process of phase shifter circuit and the results of each stage test. Through the analysis of the test results, the generality and high reliability of the satellite transponder circuit are verified.