Miniaturization Of Hydrogen Maser Magnetron Cavity Technology Research

Nowadays, due to rapidly development of space technology, precise time andfrequency are all needed for the fields relating to measurement and control for aircraft,communications and data transmission, the ground target positioning. Time frequencytechnology finds widely application for navigation and positioning, timesynchronization at base station and online communication networks. In modernscientific technologies requires time frequency technology much higher quality thanbefore, as a result, high-precision hydrogen maser has become an indispensableequipment in this field. In order to meet with the development for space technology, animportant trend is targeted on miniature hydrogen maser with higher stability, lowerweight and small size.Hydrogen maser is miniature designed in consideration of resonant cavity, beamoptical system and vacuum pump, Chief among them is the volume and weight of theresonant cavity which is most concerned. Hence, the first consideration to miniaturizethe hydrogen maser is how to design a small resonant cavity, whose structure size candetermines the minimal size and weight of the hydrogen maser.One of the methods to miniaturize the hydrogen maser resonant cavity is tosubstitute the structure of magnetron type electromagnetic field for that of electrodeloaded microwave cavity, then designed out required cavity size and model ofelectromagnetic field. Compared with the electrode loaded microwave cavity, themagnetron cavity can generate the electromagnetic structure ofTE011mode.withrelative high Q value and good fill factor. Its process is uncomplicated despite the factthat it can be made arbitrarily small base on the related theory.This article, in conjunction with electromagnetic theory, adopts the approach ofequivalent circuit for an analysis of the characteristics of metal loaded circularwaveguide, given out a resolution for solving the cutoff wave number. Hence, thecalculating equation can be obtained for resonant frequency formed due to waveguideshort in the resonant cavity and Q value. Resonant frequency in the resonant cavity and Q value can be simulated by HFSS simulation software， then compared withtheoretical value of calculation, correctness of this equation can be testified andsimultaneously the changes in the relationship between structure for metal loadeddiaphragm and resonant frequency, as well as metal loaded diaphragm and Q value canbe given out and determined by the test cases.