Broadband microwave measurement based on photonic down-conversion sampling

Abstract

Photonic down-conversion sampling is a promising technique that can directly and adaptively transfer a high-frequency microwave signal to a low-frequency replica in the first Nyquist zone, thanks to the large bandwidth of the electro-optic modulator and the ultra-short optical pulse train. Therefore, this technique is beneficial to achieving broadband microwave measurement by using a low-speed photodetector together with a low-frequency and narrowband digital (or analog) receiver. In this presentation, we will discuss broadband high-resolution microwave frequency measurement schemes based on low-speed photonic sampling, which are applicable for multi-tone signal. We will also discuss calibration-free microwave characterization of broadband electro-optic modulators based on low-speed photonic sampling, where the microwave response of either a phase modulator or an intensity modulator can be obtained through low-frequency detection.