8 Mm-band Pin Diode Spst Switch

Millimeter wave switch is a kind of millimeter wave control circuits and one of veryimportant parts of radar and test systems. The Single Pole Single Throw (SPST) switchbased on PIN diode has been researched in this dissertation. After analyzing thecharacteristic of PIN diode and the theory of SPST switch, this dissertation focus onfollowing aspects:(1) The transmission characteristic of fin-line and transition from fin-line towaveguide are simulated by MATLAB before the fin-line SPST switch is simulated byHFSS. The fin-line switch satisfies design requirements.(2) The results of microstrip switch are obtained after the switch is simulated by ADS.The results take on well characteristic: the frequency range from 33.5GHz to 36GHz, theinsertion loss is less-than 1dB and the isolation is greater than 30dB.(3) Microstrip switch is manufactured and tested. The test results indicate that theinsertion loss is about 2.5dB and the isolation is greater than 20dB in service frequency.The cause of switch performance decline is analyzed.(4) Several kinds of methods to improve switch performance are introduced. SoftwareADS is used for simulating broad-band filter switch. The results verify the new switch canwiden service frequency.