Optically controlled phased array radar receiver using SLM switched real time delays

Abstract

We report the results of a demonstration of a real time delay, optically controlled phased array radar receiver. This implementation employed a free space configuration based upon an optical switching network using liquid crystal spatial light modulators (SLM's). A three-delay unit, two-antenna array receiver was implemented at an optical wavelength of 1.3 pm and demonstrated "squint-free" operation over the entire X-band (8-12 GHz) with an angular accuracy of 1.4". Finally, a novel configuration for the two-antenna element SLM architecture was proposed and demonstrated equivalent system performance with a reduction in the number of components.

Optical pulse-burst position modulation for antenna beam forming

“…After the optical realization of the processing of the RF signals, the obtained optical output is converted back into RF signals that are transmitted using proper microwave antennas. 1 Several and most common applications in which usage of RF photonic approaches were applied are related to the generation of true time delay ͑TTD͒ 2-4 microwave pulses using optical means, 5-7 spectral analysis, 8-10 optically controlled phased array radar receivers, 11 optically controlled phased-array antennas, 12 photonic signal processing and filtering of microwave signals, [13][14][15][16] and finally, optical delay line filters. 17 In this paper, we address one application called antenna beam forming, where a burst of pulses that are modulated on top of an optical carrier is temporally shifted in time for generating TTD.…”

Silicon nanomembrane-based compact true-time-delay module on unconventional substrates

“…Photonic true-time-delay (TTD) offers better performance with reduced cost, size, weight, and power (C-SWaP) over traditional electronic solutions, especially for simultaneous multi-user, multi-target tracking capability in phased array sensor applications. Several photonic TTD schemes have been proposed to take advantages of an optical feed for TTD, including WDM technique [2][3][4][5], slow-light waveguide technique [6], monolithic waveguide technique [7], acousto-optic (AO) integrated circuit technique [8][9][10], Fourier optical technique [11][12][13], bulky optics techniques [14][15][16][17][18][19], Bragg-fiber technique, dispersive fiber technique [20][21][22][23][24], fiber grating technique [25][26], and substrate guided wave techniques [27][28][29]. Use of photonic systems on air-borne and space-borne platforms or integration of several communication and sensing units on a single chip for improved reliability will require individual components to have smaller size, lower power consumption, and lighter weight.…”

Reconfigurable true-time delay for wideband phased-array antennas

“…Ultra-wide bandwidth operation would be made viable only with a wideband true-time delay (TTD) antenna feed. Many optical schemes have been proposed to take advantages of an optical feed for true-time delay, including acousto-optic (AO) integrated circuit technique [1][2][3], Fourier optical technique [4][5][6], bulky optics techniques [7][8][9][10][11][12], dispersive fiber technique [13][14][15][16][17], fiber grating technique [18][19], and substrate guided wave techniques [20][21][22]. Time delay modules utilizing the AO technique are considerably compact and integrated.…”