Photonic generation and transmission of phase-modulated microwave signals

In modern radar system, pulse compression technique has been widely used to increase the detection distance and range resolution. To enlarge the pulse compression ratio, the microwave signals are often phase modulated, such as phase-coded or frequency chirped. Conventionally, the phase-modulated microwave signals generated by electrical methods suffer from low microwave carrier frequency, limited bandwidth, low data rate and high transmission loss. Photonic-assisted generation and transmission of phase-modulated signals is a promising candidate to overcome these limitations In this paper, we review our recent works about the photonic generation and transmission of phase-modulated microwave signals, including the simultaneously frequency up-conversion and phase-coding, background-free frequency-doubled phase-coded microwave signal generation, phase-coded microwave pulse generator by optoelectronic oscillation (OEO), as well as transmission of dual-chirped microwave signals with chromatic-dispersion-induced power fading (CDIP) compensation and elimination technology. These works represent the new progresses in photonic approaches to generate and transmit phase-modulated microwave signals, which has great potential in the modern radar system.