Liquid crystal based beam scanning reflectarrays and their potential in SATCOM antennas

Pérez-Palomino, Gerardo; Barba, M.; Encinar, José A.; Cahill, R.; Dickie, R.; Baine, Paul

doi:10.23919/eucap.2017.7928474

Cited by 14 publications

(8 citation statements)

References 9 publications

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“…Many recent papers have studied LC based reconfigurable reflectarrays, however these have mostly considered using a continuously adjustable source of voltage to control the precise phase difference [10], [11]. This design, although elaborate and precise in beam functionalities, requires much more complexity and power consumption than our proposal, which is a LC reconfigurable reflectarray with binary voltage control, i.e having only two states: ON and OFF.…”

Section: B Lc Based Reconfigurable Reflectarray Metasurfacesmentioning

confidence: 99%

Electronically Reconfigurable Binary Phase Liquid Crystal Reflectarray Metasurface at 108 GHz

Meng

Nekovee

et al. 2019

2019 IEEE Globecom Workshops (GC Wkshps)

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We have proposed a preliminary design and computation results of a 20 by 20 elements reconfigurable liquid crystal (LC) based binary phase reflectarray metasurface for applications in THz wireless communication. Specifically, we performed full-wave simulations and theoretical calculations on the far-field patterns of our proposed device, and we also developed optimisation routines for both the antenna unit cell design as well as far-field pattern synthesis algorithms. The LC used was modelled after Merck's model GT3-23001. At optimal operation frequency of 108 GHz, the phase difference between ON and OFF state is 177 degrees, and the reflection amplitudes of both states are 0.88. We were able to demonstrate 60 degrees of beam steering, which was achieved together with a (single beam) RCS of -5.8 dBm2, when the device dimension is 20mm by 20mm. The operational bandwidth is plus or minus 2 GHz from central frequency of 108 GHz.

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Section: B Lc Based Reconfigurable Reflectarray Metasurfacesmentioning

confidence: 99%

Electronically Reconfigurable Binary Phase Liquid Crystal Reflectarray Metasurface at 108 GHz

Meng

Nekovee

et al. 2019

2019 IEEE Globecom Workshops (GC Wkshps)

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“…LC based reconfigurable reflectarray metasurfaces have also been increasingly studied [10], [11], [13], due to their advantages at higher frequency regime. LC based unit antenna elements are structurally simpler than the diode counterpart, and also more suitable for high frequency applications, as PIN diodes can be lossy at THz regimes.…”

Section: B Lc Based Reconfigurable Reflectarray Metasurfacesmentioning

confidence: 99%

Reconfigurable Liquid Crystal Reflectarray Metasurface for THz Communications

Meng¹,

Nekovee²,

Wu³

2019

Antennas and Propagation Conference 2019 (APC-2019)

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We present computational studies on a proposed 400 elements electronically reconfigurable liquid crystal (LC) based binary phase reflectarray metasurface, operational at 108 GHz. LC was modelled using Merck's GT3-23001, and full wave simulations have shown a phase difference of 177 degrees between ON and OFF states, while reflection amplitudes were both 0.88 for ON and OFF. We present preliminary full wave simulation results on the Genetic Algorithm (GA) optimised far-fields. We also present the basic design procedures and cross-platform implementations on optimisation routines involving Matlab, CST and VBA environments.

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“…The beam-steering feature can be achieved by employing active components or active materials such as varactors, pin diodes, and liquid crystal in antennas [11][12][13], especially in reflectarray (RA) antennas and TA antennas for beam steering. This is achieved by changing the characteristics of the component or material without changing the structure by applying power [14][15][16][17]. However, this is also associated with a high side lobe level and does not offer much of a gain improvement.…”

Section: Introductionmentioning

confidence: 99%

Beam-Steerable Passive Transmitarray Optimized Based on an Adjacent Algorithm

Shin

2021

IEEE Access

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This paper presents a novel adjacent algorithm for the design of a beam-steerable passive transmitarray (TA) antenna. Even if the beam of a feed antenna is steering by varying the phase offset of the antenna array forming the feed antenna, the existing passive TA, which improves the gain only in the boresight direction, cannot improve the gain in all directions in which the beam is steering. To minimize the difference in the phase shift between different phase offsets by adjusting the reference phase instead of searching the entire space made up of the reference phase of each phase offset, an adjacent algorithm to change the reference phase with an adjacent phase that minimizes the objective function was adopted. This strategy improved the O(n k-1) algorithm to a linear algorithm of O(n). It was also experimentally shown that optimization using the adjacent algorithm did not change the final result regardless of the initial value. Weighing the magnitude of the electric field (E field), the average optimized phase shift was obtained to determine the phase shift of the passive TA unit cell. Simulation of a TA consisting of an effective simple medium with a thickness of 2.5 mm reflecting the previously determined phase shift showed that the gain was improved by less than 1 dB when the phase offset was 0° and by more than 1 dB when the phase offset was 75°.

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Liquid crystal based beam scanning reflectarrays and their potential in SATCOM antennas

Cited by 14 publications

References 9 publications

Electronically Reconfigurable Binary Phase Liquid Crystal Reflectarray Metasurface at 108 GHz

Electronically Reconfigurable Binary Phase Liquid Crystal Reflectarray Metasurface at 108 GHz

Reconfigurable Liquid Crystal Reflectarray Metasurface for THz Communications

Beam-Steerable Passive Transmitarray Optimized Based on an Adjacent Algorithm

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