Photonic scanning receiver for wide-range microwave frequency measurement by photonic frequency octupling and in-phase and quadrature mixing.

A photonic scanning receiver with optical frequency scanning and electrical intermediate frequency envelope detection is proposed to implement wide-range microwave frequency measurement. This system applies photonic in-phase and quadrature frequency mixing to distinguish and measure the signals in two frequency bands that mirror each other. Combined with the photonic frequency octupling technique, the proposed system has a frequency measurement range that is 16 times that of the sweeping range of the electrical signal source. Besides, optical frequency sweeping with up and down chirps is used to relax the requirement for precise synchronization between the sweeping source and the analog-to-digital converter. In the experiment, using an electrical sweeping local oscillator having a bandwidth of 1.75 GHz, the system achieves a frequency measurement range as large as 28 GHz. The measurement errors are kept within 24 MHz with an average error of 9.31 MHz.