Instantaneous microwave frequency measurement based on non-sliced broadband optical source

We propose and experimentally demonstrate a reconfigurable instantaneous frequency measurement (IFM) system. A non-sliced broadband optical source (BOS) is used to realize two tunable microwave photonic filters (MPFs) with equivalent infinite taps. The two MPFs allow us to have an amplitude comparison function (ACF) which maps the unknown frequency to microwave power. The IFM system is reconfigurable by simply adjusting two variable optical delay lines (VODLs). The principle behind the proposed IFM systems is theoretically analyzed. Experimentally, unknown frequency measurement in a frequency range of 8–16.5 GHz and 11.5–20 GHz with a measurement error of less than 110 MHz is realized.