Microwave region frequency measurement - has quartz crystal accuracy by broad band mixing into automatic digital microwave counter

摘要

An arrangement enabling the frequency range of an automatic digital microwave frequency counter to be expanded is a routinely useable combination of an electronic circuit and microwave components. It gives accuracy equivalent to square crystal measurement in the range 26 to 40 GHz but may also be used for higher frequencies. A signal lying outside the counter frequency band is converted into an intermediate frequency using a free-running oscillator whose frequency is measured by the counter, a frequency multiplier, and a broad band mixer. The intermediate and oscillator signals are alternately switched to the counter via an electromechanical or diode switch for automatic derivation of the unknown signal frequency. The switch is controlled by the counter print pulse. The multiplied oscillator frequency lies on the side of the signal band corresp. to highest mixer losses.