Photonic synthesis of broadband microwave arbitrary waveforms applicable to ultra-wideband communication

Time-Domain Measurement of the Frequency-Dependent Delay of Broadband Antennas

“…In our apparatus' current configuration, the waveform time aperture is approximately 3 ns and the finest temporal feature is ps; the latter yields an RF bandwidth of 11 GHz. This electromagnetic pulse shaping technique provides unprecedented waveform agility and enables a variety of excitation waveforms for our antenna system, which range from broadband sinusoids (constant frequency as well as frequency-stepped) [6] to highly-structured UWB impulses [7]. We note that our technique allows direct-specification of the output electrical waveform; others have demonstrated a similar technique [8] which iteratively solves for sinusoidal and frequency-modulated waveforms.…”

“…The chromatic dispersion of the optical fiber uniquely maps optical frequency to time which results in a time-domain waveform (current) from the photodiode with a temporal shape determined by that of the tailored optical power spectrum. For a detailed discussion, please consult [6] and [7]. In our apparatus' current configuration, the waveform time aperture is approximately 3 ns and the finest temporal feature is ps; the latter yields an RF bandwidth of 11 GHz.…”

“…In this work, we utilize a photonics-based electromagnetic pulse shaper [6], [7] to perform direct frequency-dependent delay measurements for several broadband antenna structures. By characterizing wireless links consisting of a pair of identical antennas, we demonstrate that we may use the delay extracted from these measurements to predict the behavior of asymmetric antenna links (those constructed using two different antenna structures).…”

Generation of Power-Efficient FCC-Compliant UWB Waveforms Using FBGs: Analysis and Experiment

“…Optical pulse generation techniques for UWB have also been proposed based on optical spectral shaping and frequency-totime conversion [6]- [9], a principle first established in [11]. The general concept of this technique is depicted in Fig.…”

“…The reflection type of this device is used in [6], where SLM is replaced by a single-layer 0733-8724/$25.00 © 2008 IEEE liquid crystal modulator (LCM). Although these arbitrary waveform generators offer tremendous flexibility, and could generate the desired UWB pulse, they cannot be used in many applications due to their large size and high optical loss.…”