True-time delay beamforming using semiconductor optical amplifier and tunable dispersion medium

Abstract

We demonstrated optical phased array antenna based on true-time delay (TTD) beamforming for radio-over-fiber (RoF) using semiconductor optical amplifier (SOA) and tunable dispersion medium. In the case of the full range of beam direction, the required delay time per antenna element was 194 ps. As a result, the full true time delay was obtained by adjusting the dispersion value of the tunable dispersion medium (TDM) from 400 ps/nm to +400 ps/nm. We successfully achieved the high TTD performance for various output beam angles.

Antenna Phased Array Beamforming at 26 GHz Using Optical True Time-Delay

“…The TTD was realized by a combination of optical sources at different wavelengths, wavelength division multiplexers (WDMs) and optical fiber delay lines, with optical 2x2 switches activating variable optical fibers paths to introduce phase difference between particular branches. The effect of chromatic dispersion was used in [10] where a tunable dispersion medium served as TTD was used for beamforming up to ± 90° at 5 GHz using a 4-element antenna array. A 38-GHz mmw beam steered fiber and wireless system has been proposed in [11] based on an arrayed waveguide grating feedback loop.…”

MWP true time delay implemented in PbS-SU8 waveguides

“…In this way, one fundamental key block of several MWP functionalities, for example in tunable filtering, is the true time delay (TTD) device, useful to overcome limitations of the conventional electrical approximations, like frequency-dependent losses, or to enable ultra wideband operation. Examples of photonics TTDs architectures are the use of optical fibre links along with a tunable laser to feed a phase array antenna system [5], the use of semiconductor optical amplifiers (SOAs) [6] or microring resonators [7]. Nevertheless, these implementations showed some drawbacks, for instance optical links lack of flexibility, SOAs showed RIN limitations and distortions and microring resonators have a narrowband behaviour.…”

Continuous Broadband MWP True-Time Delay With PbS-PMMA and PbS-SU8 Waveguides

“…In this way, one fundamental key block of several MWP functionalities, for example in tunable filtering, is the TTD device, useful to overcome limitations of the conventional electrical approximations, like frequency-dependent losses, or to enable ultra-wideband operations. Examples of photonics TTDs architectures are the use of optical fiber links along with a tunable laser to feed a phase array antenna system [7], the use of semiconductor optical amplifiers (SOAs) [8] or microring resonators [9]. Nevertheless, these implementations showed some drawbacks, for instance, lack of flexibility of optical links, relative intensity noise (RIN) limitations and distortions of SOAs and narrowband behavior of microring resonators in terms of tuning speed.…”