Strategies for improved temporal response of glass-based optical switches

We present an optimization of the dynamics of integrated optical switches based on thermal phase shifters. These devices have been fabricated in the volume of glass substrates by femtosecond laser micromachining and are constituted by an integrated Mach–Zehnder interferometer and a superficial heater. Simulations, surface micromachining and innovative layouts allowed us to improve the temporal response of the optical switches down to a few milliseconds. In addition, taking advantage of an electrical pulse shaping approach where an optimized voltage signal is applied to the heater, we proved a switching time as low as 78 µs, about two orders of magnitude shorter with respect to the current state of the art of thermally-actuated optical switches in glass.

Collective unitary evolution with linear optics by Cartan decomposition

Unitary operation is an essential step for quantum information processing. We first propose an iterative procedure for decomposing a general unitary operation without resorting to controlled-NOT gate and single-qubit rotation library. Based on the results of decomposition, we design two compact architectures to deterministically implement arbitrary two-qubit polarization-spatial and spatial-polarization collective unitary operations, respectively. The involved linear optical elements are reduced from 25 to 20 and 21 to 20, respectively. Moreover, the parameterized quantum computation can be flexibly manipulated by wave plates and phase shifters. As an application, we construct the specific quantum circuits to realize two-dimensional quantum walk and quantum Fourier transformation. Our schemes are simple and feasible with the current technology.

A dual parallel Mach–Zehnder modulator linearization scheme based on 90° phase shifters

In this paper, a dual-drive dual-parallel Mach–Zehnder Modulator based linearization scheme is implemented by utilizing only two phase shifters and comprehensively demonstrated for a photonic transmission link. Third order intermodulation distortion is suppressed by adjusting angles of electrical phase shifters i.e. π/2 and−π/2 and a non-linear distortion immune system can be proposed for microwave photonic link. A complete suppression in intermodulation terms and 20.8 dB enhancements are found in spurious free dynamic range (SFDR). SFDR reaches 135.6 dB Hz4/5 by suppressing major spurious contributors of third order intermodulation distortions in optical domain only which ensures the improvement in performance of link against non-linear terms.

Design and Development of Novel Hybrid Precoder for Millimeter-Wave MIMO System

Power consumption and hardware cost reduction with the use of hybrid beamforming in large-scale millimeter wave MIMO systems. The large dimensional analog precoding integrates with the hybrid beamforming based on the phase shifters including digital precoding with lower dimensionality. The reduction of Euclidean distance between the hybrid precoder and fully digital is the major problem to overcome the minimization of resultant spectral efficiency. The issue formulates as a fully digital precoder’s matrix factorization problem based on the analog RF precoder matrix and the digital baseband precoder matrix. An additional element-wise unit modulus constraint is imposed by the phase shifters on the analog RF precoder matrix. The traditional methods have a problem of performance loss in spectral efficiency. In the processing time and iteration, high complexities result in optimization algorithms. In this paper, a novel low complexity algorithm proposes which maximizes the spectral efficiency and reduces the computational processing time.

5G Millimeter-Wave Beamforming System using Substrate Integrated Waveguide

Beamforming is a key element of 5G that uses advanced antenna technologies to focus a wireless signal to a defined direction. Butler Matrix (BM) as a beamforming network is used to control the beam direction by utilizing the amplitude and the output phase. A particular technique for designing BM is through substrate integrated waveguide (SIW), which is used to realize the bilateral edge wall vias where the waveguide mode propagates through to support the current flow and reduce the loss of surface wave. Unlike conventional BM, the proposed design requires only hybrid couplers and phase shifter without any crossover. In this BM structure, the SIW hybrid coupler is designed, with two phase shifters of -90°, and one phase shifter of -180° to control the amplitude and phase shifting. This results in an optimized transmission amplitude and output phase difference. The BM also circumvents any crossover, to provide minimal losses. The hybrid coupler exhibits Sii and Sij characteristics at 28 GHz, with values of -27.35 dB for return loss, -3.9 dB for insertion loss, -3.2 dB for coupling, and -26.54 dB for the isolation. In the BM design, high transmission efficiency is observed where the return loss is less than -10 dB, while minimal transmission amplitudes are obtained within the values of ‒6 ± 3 dB. The three-port BM is designed using SIW with minimal loss and the phase difference at each respective output port of the BM shows values of 0°, -120°, and 120°. The three consecutive beams with the gains of 11.1 dBi for port 1 excitation, 9.06 dBi for port 2 excitation and 10.4 dBi for port 3 excitation is achieved when the antenna array is fed to the BM, and each of the radiated beams has beam angles of 0, -27 and 27 degrees.

POWER COMPONENTS ESTIMATION ACCORDING TO IEEE STANDARD 1459-2010

In this paper, the design and implementation of a novel recursive method for the power measurement according to the IEEE Standard 1459–2010 have been described. The most important parts are adaptive band- and low-pass FIR filters that extract fundamental and dc components, respectively. In addition, by using oversampling techniques and decimation filters, coefficient sensitivity problems of the large-order FIR comb cascade structure are overridden and the parameter estimation accuracy is improved. The symmetrical components are estimated through transformation matrix of adaptive phase shifters. The effectiveness of the proposed techniques is demonstrated by simulation results.

Influence of displacement and patterning of phase shifters for piston mode operation of temperature compensated surface acoustic wave resonators on SiO2/LiNbO3 structure

This paper discusses influence of displacement and patterning of phase shifters for piston mode operation of the temperature compensated (TC) surface acoustic wave (SAW) resonator on SiO2/LiNbO3 structure. As the phase shifters, Cu metals placed on the top surface of SiO2 are considered. First, the conventional Cu stripes are chosen, and their displacement are considered from IDT aperture edges. It is shown that achievable transverse mode suppression is almost identical when the stripe shape is adjusted for each case. Next, Cu dots are considered as patterned phase shifters. It is shown comparable transverse mode suppression is possible also for this case. However, relatively strong SAW lateral leakage occurs when they are placed above IDT fingers. These results indicate that location and pattern can be added as design parameters for the phase shifters on SiO2. It is favorable for further enhancement of total device performances.