The quantities required to be measured in microwave circuits are frequency, power and impedance. Microwave frequency measurement is done by slotted line, resonant cavities and transfer oscillator. Microwave power measurement uses bolometers and micromave power meters. A self balancing bridge working on the principle of power substitution is commomly used. Microwave impedance measurement is done by measurement of reflection coefficient and VSWR. A slotted line and probe is a basic tool for these measurements.' Network analyser enables rapid impedance measurement over a broad frequency range.