Ring resonator-based broadband photonic beam former for phased array antennas

This thesis presents the principles and a demonstration of optical ring resonator\ud (ORR)-based broadband photonic beam former for phased array antennas. In\ud Chapter 1 an introduction of RF photonics is given. The SMART and BPB projects\ud are summarized, which are aimed for the development of ORR-based broadband\ud photonic beam former for phased array antennas. In the SMART project the antenna\ud is used for the aeronautic communication of Ku-band signals; in the BPB project the\ud antenna is part of a radio telescope which is used for astronomical research

Integrated photonic K_u-band beamformer chip with continuous amplitude and delay control

We present the first demonstration of a broadband and continuously tunable integrated optical beamforming network (IOBFN) capable of providing continuously tunable true-time-delay up to 236 ps over the entire DVB-S band (10.7–12.75 GHz), realized with a CMOS compatible process. The tunable delays are based on reconfigurable optical ring resonators in conjunction with a single optical sideband filter integrated on the same optical chip. The delays and filter responses are software programmable. Four tunable delay lines are integrated on a single chip and configured to feed a 16-element linear antenna array. The broadband beam steering capability of the proposed IOBFN is demonstrated by the squint-free antenna pattern generated from the measured RF amplitude and phase responses of the optical delay line

Novel ring resonator-based integrated photonic beamformer for broadband phased array receive antennas - part I: design and performance analysis

A novel optical beamformer concept is introduced that can be used for seamless control of the reception angle in broadband wireless receivers employing a large phased array antenna (PAA). The core of this beamformer is an optical beamforming network (OBFN), using ring resonator-based broadband delays, and coherent optical combining. The electro-optical conversion is performed by means of single-sideband suppressed carrier modulation, employing a common laser, Mach-Zehnder modulators, and a common optical sideband filter after the OBFN. The unmodulated laser signal is then re-injected in order to perform balanced coherent optical detection, for the opto-electrical conversion. This scheme minimizes the requirements on the complexity of the OBFN, and has potential for compact realization by means of full integration on chip. The impact of the optical beamformer concept on the performance of the full receiver system is analyzed, by modeling the combination of the PAA and the beamformer as an equivalent two-port RF system. The results are illustrated by a numerical example of a PAA receiver for satellite TV reception, showing that—when properly designed—the beamformer hardly affects the sensitivity of the receiver

Electronically-steered KU band phased array antenna comprising an integrated photonic beamformer

A phased-array antenna that includes a photonic beamformer is disclosed. In some embodiments, a front stage of electrical-domain processing applies a 16-to-1 signal-combination ratio, a single stage of photonic beamforming applies a 4-to-1 signal-combination ratio, and a passive, electrical-domain, signal combiner applies a 32-to-1 signal-combination ratio

Low-loss chip-scale programmable silicon photonic processor

Chip-scale programmable optical signal processors are often used to flexibly manipulate the optical signals for satisfying the demands in various applications, such as lidar, radar, and artificial intelligence. Silicon photonics has unique advantages of ultra-high integration density as well as CMOS compatibility, and thus makes it possible to develop large-scale programmable optical signal processors. The challenge is the high silicon waveguides propagation losses and the high calibration complexity for all tuning elements due to the random phase errors. In this paper, we propose and demonstrate a programmable silicon photonic processor for the first time by introducing low-loss multimode photonic waveguide spirals and low-random-phase-error Mach-Zehnder switches. The present chip-scale programmable silicon photonic processor comprises a 1×4 variable power splitter based on cascaded Mach-Zehnder couplers (MZCs), four Ge/Si photodetectors, four channels of thermally-tunable optical delaylines. Each channel consists of a continuously-tuning phase shifter based on a waveguide spiral with a micro-heater and a digitally-tuning delayline realized with cascaded waveguide-spiral delaylines and MZSs for 5.68 ps time-delay step. Particularly, these waveguide spirals used here are designed to be as wide as 2 µm, enabling an ultralow propagation loss of 0.28 dB/cm. Meanwhile, these MZCs and MZSs are designed with 2-µm-wide arm waveguides, and thus the random phase errors in the MZC/MZS arms are negligible, in which case the calibration for these MZSs/MZCs becomes easy and furthermore the power consumption for compensating the phase errors can be reduced greatly. Finally, this programmable silicon photonic processor is demonstrated successfully to verify a number of distinctively different functionalities, including tunable time-delay, microwave photonic beamforming, arbitrary optical signal filtering, and arbitrary waveform generation

Picosecond optical pulse processing using a terahertz-bandwidth reconfigurable photonic integrated circuit

Chip-scale integrated optical signal processors promise to support a multitude of signal processing functions with bandwidths beyond the limit of microelectronics. Previous research has made great contributions in terms of demonstrating processing functions and device building blocks. Currently, there is a significant interest in providing functional reconfigurability, to match a key advantage of programmable microelectronic processors. To advance this concept, in this work, we experimentally demonstrate a photonic integrated circuit as an optical signal processor with an unprecedented combination of two key features: reconfigurability and terahertz bandwidth. These features enable a variety of processing functions on picosecond optical pulses using a single device. In the experiment, we successfully verified clock rate multiplication, arbitrary waveform generation, discretely and continuously tunable delays, multi-path combining and bit-pattern recognition for 1.2-ps-duration optical pulses at 1550 nm. These results and selected head-to-head comparisons with commercially available devices show our device to be a flexible integrated platform for ultrahigh-bandwidth optical signal processing and point toward a wide range of applications for telecommunications and beyond