Review of microwave frequency measurement circuits

In this work, microwave frequency measurement (MFM) is reviewed since the early stages using fully analog implementations, including its evolution to analog/digital implementations with high resolutions up 1 MHz. The review includes digital and photonics techniques, a discussion on achieved devices overall field of measuring identifying unknown signals. Several planar such as interferometers, filters, selective surfaces have been proposed design low-cost low-power MFM systems. presented here show from MHz 940 operate in range 0.15 GHz 11.5 GHz, having typical bandwidths 2 GHz. techniques involve mapping signal into optical spectrum create frequency-power function, that uniquely identifies signal, large immunity electromagnetic interference.