Microwave frequency counters
Time-Frequency instrumentation - High frequencies and phase noise measurement

As shown in [R 687] , a frequency counter is limited in its frequency range by the speed of its logic circuits. Today, basic commercial meters have a frequency range of around 300 MHz. The microwave spectrum is defined approximately for the frequency range 0.3 GHz to 300 GHz. Most common applications use the range from 1 GHz to 40 GHz.

The designer of a microwave frequency counter must turn to forms of down-conversion to extend the measurement frequency to values above 300 MHz.