Microwave Measurement of Varactor Diode Q-factors without Matching or Standard Impedances†

†Communicated by the Author

Abstract

It is shown that Q-factors of varactor diodes may be measured at microwave frequencies without the usual procedures of matching into the diodes series resistance or the use of calibrating impedances and that a very simple method is possible with an arbitrary fixed lossless transformation between the measuring line and the diode element. Used in conjunction with an automatic impedance display unit and a modified Smith chart the method leads to a direct display of varactor Q's. It is possible to show also the varactor series resistance and capacitance on the same display but this involves calibration with known impedances.

Notes

†Communicated by the Author