scholarly journals Grating Lobe-Free Beam Steering through Optical Phase Array Using Phase-Compensated Two Index-Mismatched Silicon Wires-Based Emitters

2020 ◽  
Vol 10 (4) ◽  
pp. 1225
Author(s):  
Rong-An Zhang ◽  
Ting-Sheng Lin ◽  
Wai-Ting Liu ◽  
Shih-Hsiang Hsu ◽  
Che-Chang Chang

The beam formation can be treated as the diffraction pattern. A 1-D light detection and ranging beam steering could be derived through a phase shifter array using Rayleigh–Sommerfeld Diffraction, which is then utilized to demonstrate grating lobe-free beam steering from the optical phase array emitter with half-wavelength pitches. The half-wavelength pitch cannot demonstrate beam formation without any evanescent coupling blocking between emitters. Here, two index-mismatched silicon wires in the emitter array are proposed by the optical phase compensation through waveguide width adjustment, to avoid the complex and addressable thermal control on the phase shifters. Moreover, the same output optical waveguide mode needs to be further considered to demonstrate the grating lobe-free beam steering. In order to get the adiabatic connection between two different pitches between the phase shifter and emitter, an optical path equalization will also be applied.

2014 ◽  
Vol 41 (2) ◽  
pp. 0202002
Author(s):  
师宇斌 Shi Yubin ◽  
马浩统 Ma Haotong ◽  
马阎星 Ma Yanxing ◽  
吕洋 Lü Yang ◽  
司磊 Si Lei

Author(s):  
Christopher T. Phare ◽  
Min Chul Shin ◽  
Jahnavi Sharma ◽  
Sohail Ahasan ◽  
Harish Krishnaswamy ◽  
...  

Photonics ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 56
Author(s):  
Youngin Kim ◽  
Hyeonho Yoon ◽  
Jong-Bum You ◽  
Minchul Kim ◽  
Hyo-Hoon Park

We demonstrate wide-angle beam-steering using an optical phased array (OPA) with waveguide radiators designed with non-uniform widths to reduce the crosstalk between waveguides. The OPA consists of a silicon based 1 × 16 array of electro-optic phase shifters and end-fire radiators. The 16 radiators were configured with four different widths and a half-wavelength spacing, which can remove the higher-order diffraction patterns in free space. The waveguides showed a low crosstalk of −10.2 dB at a wavelength of 1540 nm. With phase control, the OPA achieved wide beam-steering of over ±80° with a side-lobe suppression of 7.4 dB.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Md. Mazidul Islam ◽  
Mikko Leino ◽  
Rasmus Luomaniemi ◽  
Jinsong Song ◽  
Risto Valkonen ◽  
...  

This paper presents a new implementation of the beam-steerable two-dimensional phased antenna array for the forthcoming 5G networks. The antenna enables easy integration of phase shifters and other active electronics on a single PCB, low-loss feed network, low profile, and beam steering in both azimuth and elevation plane. In addition, the antenna is scalable in the number of elements and it can be made compatible with low-cost mass production in plastic injection molding with a metal coating. The antenna consists of a rectangular waveguide feed network, waveguide-to-PCB transitions, phase shifters on a PCB, and horn antenna radiating elements. The parts have been first designed and simulated individually and the operation of the whole structure is then verified by electromagnetic simulations. The phase shifter used in this work is a meandered microstrip line section, but the structure also enables the implementation of active phase shifters. A four-by-four antenna array prototype was manufactured. The beam-steering properties of the phased antenna array have been tested with radiation pattern measurements at 72.5 GHz, and the measured gains are compared with the simulated ones. The measured gains are 15.2 and 11.2 dBi for the boresight beam, and the beam was steered to 40°.


2019 ◽  
Vol 58 (34) ◽  
pp. G241 ◽  
Author(s):  
Colton M. Bigler ◽  
Zachary Rovig ◽  
Joshua McDonald ◽  
Pierre-Alexandre Blanche

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 514 ◽  
Author(s):  
Rolf Jakoby ◽  
Alexander Gaebler ◽  
Christian Weickhmann

Future satellite platforms and 5G millimeter wave systems require Electronically Steerable Antennas (ESAs), which can be enabled by Microwave Liquid Crystal (MLC) technology. This paper reviews some fundamentals and the progress of microwave LCs concerning its performance metric, and it also reviews the MLC technology to deploy phase shifters in different topologies, starting from well-known toward innovative concepts with the newest results. Two of these phase shifter topologies are dedicated for implementation in array antennas: (1) wideband, high-performance metallic waveguide phase shifters to plug into a waveguide horn array for a relay satellite in geostationary orbit to track low Earth orbit satellites with maximum phase change rates of 5.1°/s to 45.4°/s, depending on the applied voltages, and (2) low-profile planar delay-line phase shifter stacks with very thin integrated MLC varactors for fast tuning, which are assembled into a multi-stack, flat-panel, beam-steering phased array, being able to scan the beam from −60° to +60° in about 10 ms. The loaded-line phase shifters have an insertion loss of about 3 dB at 30 GHz for a 400° differential phase shift and a figure-of-merit (FoM) > 120°/dB over a bandwidth of about 2.5 GHz. The critical switch-off response time to change the orientation of the microwave LCs from parallel to perpendicular with respect to the RF field (worst case), which corresponds to the time for 90 to 10% decay in the differential phase shift, is in the range of 30 ms for a LC layer height of about 4 µm. These MLC phase shifter stacks are fabricated in a standard Liquid Crystal Display (LCD) process for manufacturing low-cost large-scale ESAs, featuring single- and multiple-beam steering with very low power consumption, high linearity, and high power-handling capability. With a modular concept and hybrid analog/digital architecture, these smart antennas are flexible in size to meet the specific requirements for operating in satellite ground and user terminals, but also in 5G mm-wave systems.


2014 ◽  
Author(s):  
Mischa Megens ◽  
Byung-Wook Yoo ◽  
Trevor Chan ◽  
Weijian Yang ◽  
Tianbo Sun ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Evangelos Vassos ◽  
James Churm ◽  
Jeff Powell ◽  
Colin Viegas ◽  
Byron Alderman ◽  
...  

AbstractA low loss metamaterial unit cell is presented with an integrated GaAs air-bridged Schottky diode to produce a dynamically tunable reflective phase shifter that is capable of up to 250° phase shift with an experimentally measured average loss of 6.2 dB at V-band. The air-bridged Schottky diode provides a tuneable capacitance in the range between 30 and 50 fF under an applied reverse voltage bias. This can be used to alter the resonant frequency and phase response of a split patch unit cell of a periodic metasurface. The air-bridged diode die, which is flip-chip soldered to the patch, has ultra-low parasitic capacitance and resistance. Simulated and measured results are presented which verify the potential for the attainment of diode switching speeds with acceptable losses at mmWave frequencies. Furthermore the study shows that this diode-based unit cell can be integrated into metamaterial components, which have potential applications in future mmWave antenna beam-steering, intelligent reflecting surfaces for 6G communications, reflect-arrays, transmit-arrays or holographic antennas.


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