Compact optical true time delay beamformer for a 2D phased array antenna using tunable dispersive elements

Abstract

A hardware-compressive optical true time delay architecture for 2D beam steering in a planar phased array antenna is proposed using fiber-Bragg-grating-based tunable dispersive elements (TDEs). For an M×N array, the proposed system utilizes N TDEs and M wavelength-fixed optical carriers to control the time delays. Both azimuth and elevation beam steering are realized by programming the settings of the TDEs. An experiment is carried out to demonstrate the delay controlling in a 2×2 array, which is fed by a wideband pulsed signal. Radiation patterns calculated from the experimentally measured waveforms at the four antennas match well with the theoretical results.

Microwave Photonic Array Radars

“…To this end, we demonstrate a compact photonic RF beamformer with the schematic diagram shown in Fig. 13 [70]. When applied to an M×N array, the beamformer contains M lasers with different wavelengths and N tunable dispersive elements (TDEs), which are thermally-tuned chirped FBGs.…”

Microwave Photonic Radars

“…Here, all the dispersive delay elements are shared by the two RF beams. The concept of device reuse can also be applied to the beamforming network for planar arrays [318]. As shown in Fig.…”

Broadband Microwave Signal Processing Enabled by Polarization-Based Photonic Microwave Phase Shifters

“…Previously, a lot of methods have been reported to realize the OBFN [67]- [72], which can mainly be divided into two categories. One is based on true time delay units [67]- [69], and the other is using photonic microwave phase shifters [70]- [72]. Although the true-time-delay based OBFN can realize squintfree beamforming over a broad bandwidth [67]- [69], OBFNs based on photonic microwave phase shifters are still interesting if the instantaneous bandwidth is not large.…”