A novel photonics channelization spectrum stitching technique in a dual-OFC-based photonic channelizer for receiving a wide-band signal is proposed. By studying the slow and rapid variant characteristics of the channel differences separately, all the channels’ responses are precisely estimated and stitched in the frequency domain. A proof-of-concept experiment is performed and signals with 3 GHz bandwidth are recovered with an SNR loss of 1.01 dB.
A photonic-assisted dual-band coherent radar transmitter system with a large frequency tunable range is proposed and demonstrated. This dual-band transmitter is composed of a triple-loop optoelectronic oscillator (OEO) link, a low frequency band subsystem (LFBS) and a high frequency band subsystem (HFBS). The triple-loop OEO link is developed for the generation of an ultralow phase noise microwave signal with a large tunable range, microwave photonic down-converting is used in the LFBS to change band range, microwave photonic frequency multiplying is applied in the HFBS to achieve the bandwidth extension. The band ranges of the proposed dual-band transmitter can cover from S to Ka six bands in all. Performances in the time and the frequency domains of the dual-band microwave signals are also investigated.
In this paper, a microwave photonic dual band radar based on a photonic-assisted de-chirp processing receiver is proposed. The dual band operation is realized independently and simultaneously with a single set of hardware. At a transmitter end, two linear frequency-modulated signals separately located in C-band and Ku-band are transmitted, echoes are collected and sent to a receiver to implement photonic-assisted de-chirp processing. At the receiver end, a main modulator with a special structure, which consists of four parallel sub-modulators, is employed. The echoes and reference signals of C-band and Ku-band are applied to two pairs of sub-modulators of the main modulator, which are biased at the peak points for C-band and biased at the null points for Ku-band. In this case, the intermediate frequency signals of C-band and Ku-band produced by de-chirp processing locate at two different frequencies. Thus operation in different bands based on a unified system is achieved. An experiment operating in C-band and Ku-band with a bandwidth of 700 MHz and 3600 MHz is conducted. The results verify the concept of the dual band radar and show the potential of photonic technology to improve the performance of modern radar system.