A simple photonic generation of linearly chirped microwave pulse with large time-bandwidth product and high compression ratio

Abstract

Based on the heterodyne beating between the pre-chirped optical pulse and the continuous wave (CW) light in a wideband photodetector (PD), linearly chirped microwave pulse with time duration of 3.2ns and bandwidth of 33GHz, which yields a large time-bandwidth product (TBWP) of 106 and high compression ratio of 160, is generated in our experiment. Dispersion compensation fiber (DCF) with uniform response across broad bandwidth is used for providing the original linear chirp in our method, which shows the promise to generate linearly chirped microwave pulse with bandwidth of up to THz. The flexibility of the center frequency and the stability of the time-frequency performance are demonstrated by generating different types of linearly chirped microwave pulses. The range resolution of our generated microwave pulse is also verified by off-line processing.

Photonics-based real-time ultra-high-range-resolution radar with broadband signal generation and processing

“…Recently, microwave photonic technologies have been proposed as a promising solution for the generation, detection, and processing of high-frequency RF signals 3–6 , taking advantage of the high-frequency and broadband operation capability provided by optical components. Up to now, a lot of schemes for photonic generation of broadband LFM signals have been demonstrated 7–10 , where a signal bandwidth over 10 GHz can be easily achieved. However, fast and convenient processing of such broadband signals without sacrificing signal fidelity is still a difficult task.…”

Chirped Microwave Pulse Generation Using an Integrated SiP Bragg Grating in a Sagnac Loop

“…As it can be inferred from Eqs. (1)(2)(3)(4)(5)(6)(7)(8)(9), the imperfections of the spectral phase response of the CBG, i.e. the group delay ripples (GDRs), can cause deviations in the instantaneous frequency, and the target central frequency and chirp rate of the generated microwave pulses.…”

“…This approach benefits from the extremely large bandwidth available in the optical domain, and several interesting photonics-based techniques have been demonstrated for high-frequency microwave waveform generation [4]- [11]. The main demonstrated approaches for photonic generation of microwave pulses include techniques based on spatial-domain optical filtering [4], [5], linearly chirped optical pulse interference [6], heterodyne beating between a pre-chirped optical pulse and a continuous wave light [7], and optical spectral shaping followed by linear or nonlinear frequency-to-time mapping (FTM) in a dispersive element [8]- [10]. Integrated silicon photonic (SiP) solutions are attracting considerable attention [11]- [13] to implement microwave photonic signal processing systems to address issues such as compactness, manufacturability, stability, and reliability.…”

Photonic generation of low phase noise arbitrary chirped microwave waveforms with large time-bandwidth product

“…Compared with the conventional electrical approaches, photonic techniques, benefiting from the intrinsic advantages of modern photonics such as ultra-high bandwidth, high-speed, compactness, and electromagnetic interference immunity [13,14], are promising approaches for generating low phase noise and broadband frequency-chirped MW and sub-THz signals. Many photonic techniques aiming at the generation of chirped signals have been proposed and demonstrated during the past few years [15][16][17][18][19][20][21]. One most popular method is based on the heterodyne beating between two optical carriers of different frequency sweeping features.…”