Integrated Microwave Photonics for Spectral Analysis, Waveform Generation, and Filtering

Recent Trends and Advances of Silicon-Based Integrated Microwave Photonics

“…A key device for the generation of an arbitrary waveform in the SS-WTT system is therefore the spectral shaper that is designed to exhibit an amplitude spectral response with a shape corresponding to a scaled version of the temporal microwave waveform to be generated. Several on-silicon-chip spectral shapers have been proposed recently to generate various shapes of microwave waveforms [22,26,40,[136][137][138]. Among them, linearly chirped microwave waveforms (LCMW) are of particular interest due to their range of applications in instrumentation, imaging, and Several on-silicon-chip spectral shapers have been proposed recently to generate various shapes of microwave waveforms [22,26,40,[136][137][138].…”

“…Several on-silicon-chip spectral shapers have been proposed recently to generate various shapes of microwave waveforms [22,26,40,[136][137][138]. Among them, linearly chirped microwave waveforms (LCMW) are of particular interest due to their range of applications in instrumentation, imaging, and Several on-silicon-chip spectral shapers have been proposed recently to generate various shapes of microwave waveforms [22,26,40,[136][137][138]. Among them, linearly chirped microwave waveforms (LCMW) are of particular interest due to their range of applications in instrumentation, imaging, and communications [139].…”

“…For example, they can be compressed to increase the detection distance and improve the measurement resolution for radar systems. Important characteristics of chirped RF waveforms include the central frequency ( f RF ), amount of RF chirp, and time bandwidth product (TBWP) (a larger TBWP allows for a higher compression ratio) [138]. For LCMW generation, the optical spectral shaper should exhibit a spectral amplitude response with an increasing or decreasing FSR.…”

“…Courtesy of and adapted from Jianping Yao [22,137]. (j-m) Spectral shaper of generation of multiple chirped RF waveforms reported in [138]: (j,k) proposed spectral shapers based on (j) parallel distributed Fabry-Pérot cavities (DFPCs) and (k) an arrayed waveguide Sagnac interferometer (AWGSI) incorporating LCBGs; (l,m) Experimental results for simultaneous generation of two chirped RF waveforms using the spectral shapers based on (l) DFPCs and (m) AWGSI incorporating LCBGs: top figure shows the measure spectra, middle figure shows the temporal waveforms, and bottom figure shows the calculated spectrograms.…”

“…On the other hand, generating multiple LCMWs simultaneously, i.e., that are wavelength-division-multiplexed (WDM), can enhance the functionality of instrumentation and imaging systems. In [40,138], Chen et al showed how the parallelism of optics can be exploited to generate multiple LCMWs with different f RF and chirp rate simultaneously using parallel distributed Fabry-Pérot cavities (DFPC), and multiple LCBGs incorporated in an arrayed waveguide Sagnac interferometer (AWGSI). As the first design, Figure 23j shows the spectral shaper scheme based on two parallel DFPCs.…”