Liquid metal-based tunable linear phase shifters with low insertion loss, high phase resolution, and low dispersion
Liquid metal-based tunable linear phase shifters with low insertion loss, high phase resolution, and low dispersion
A linear, tunable, and self-compensating phase shifter based on liquid metal (LM) is proposed in this article using a half-mode substrate-integrated waveguide (HMSIW). The key phase shifting element is a via-pad-slot (VPS) structure where a thru via is attached to a pad surrounded by an annular slot. This is equivalent to a shunt capacitance and inductance loaded on the HMSIW. Phase shift is achieved when the annular slot is covered by the LM that runs in microfluidic channels on the surface of the HMSIW. This allows easy implementation and convenient manipulation of the LM without incurring excessive losses. A self-compensation structure, based on multiple rows of VPSs, is proposed to achieve a low phase deviation with frequency (low dispersion). The design method to ensure a linear and small phase step over a large phase range is presented. Two phase shifters have been designed and experimentally verified. Phase shifter-I, with two VPS rows, provides a phase shift from 0° to 41° with ±1° phase deviation with frequency over 9.5-12.5 GHz. The average phase resolution is 1°. The measured insertion loss (IL) is 0.8 ± 0.1 dB, with a figure of merit of 45.6°/dB. Phase shifter-II uses three VPS rows to provide a phase shift from 0° to 180° with a phase resolution of 1.68°. The achieved phase deviation with frequency is within ±2° over 10-12.5 GHz and within ±5° over 9-13 GHz. The measured IL is 1.1 ± 0.1 dB with a competitively high figure of merit of 163.6°/dB. Unlike many other phase shifters, the loss of the proposed phase shifters does not increase with the phase shift. The measurements are in very good agreement with the circuit analysis and simulations. The proposed linear phase shifter has demonstrated high performance and very attractive features such as low IL that does not strongly depend on the phase shift, linear phase change, high phase resolution, and low phase dispersion with frequency. Compared with other LM-enabled phase shifters, it has the advantage of easy implementation and control. This LM-based phase shifter also potentially has high power handling capability.
Capacitance, Dispersion, High phase resolution, linear phase modulation, liquid metal (LM), low dispersion, low insertion loss (IL), P-i-n diodes, phase compensation, Phase shifters, phase shifters, Slabs, Tuning, Varactors
3968-3978
Wu, Yi Wen
9ee1023a-7e89-4260-9030-5c8b9fb2e1d8
Tang, Shi Yang
1d0f15c6-2a3e-4bad-a3d8-fc267db93ed4
Churm, James
7bf3fe1f-6c68-414d-83c4-ddce7f68b643
Wang, Yi
ebcb380d-f22c-4284-9b4d-60c4e0775cbe
1 September 2023
Wu, Yi Wen
9ee1023a-7e89-4260-9030-5c8b9fb2e1d8
Tang, Shi Yang
1d0f15c6-2a3e-4bad-a3d8-fc267db93ed4
Churm, James
7bf3fe1f-6c68-414d-83c4-ddce7f68b643
Wang, Yi
ebcb380d-f22c-4284-9b4d-60c4e0775cbe
Wu, Yi Wen, Tang, Shi Yang, Churm, James and Wang, Yi
(2023)
Liquid metal-based tunable linear phase shifters with low insertion loss, high phase resolution, and low dispersion.
IEEE Transactions on Microwave Theory and Techniques, 71 (9), .
(doi:10.1109/TMTT.2023.3248954).
Abstract
A linear, tunable, and self-compensating phase shifter based on liquid metal (LM) is proposed in this article using a half-mode substrate-integrated waveguide (HMSIW). The key phase shifting element is a via-pad-slot (VPS) structure where a thru via is attached to a pad surrounded by an annular slot. This is equivalent to a shunt capacitance and inductance loaded on the HMSIW. Phase shift is achieved when the annular slot is covered by the LM that runs in microfluidic channels on the surface of the HMSIW. This allows easy implementation and convenient manipulation of the LM without incurring excessive losses. A self-compensation structure, based on multiple rows of VPSs, is proposed to achieve a low phase deviation with frequency (low dispersion). The design method to ensure a linear and small phase step over a large phase range is presented. Two phase shifters have been designed and experimentally verified. Phase shifter-I, with two VPS rows, provides a phase shift from 0° to 41° with ±1° phase deviation with frequency over 9.5-12.5 GHz. The average phase resolution is 1°. The measured insertion loss (IL) is 0.8 ± 0.1 dB, with a figure of merit of 45.6°/dB. Phase shifter-II uses three VPS rows to provide a phase shift from 0° to 180° with a phase resolution of 1.68°. The achieved phase deviation with frequency is within ±2° over 10-12.5 GHz and within ±5° over 9-13 GHz. The measured IL is 1.1 ± 0.1 dB with a competitively high figure of merit of 163.6°/dB. Unlike many other phase shifters, the loss of the proposed phase shifters does not increase with the phase shift. The measurements are in very good agreement with the circuit analysis and simulations. The proposed linear phase shifter has demonstrated high performance and very attractive features such as low IL that does not strongly depend on the phase shift, linear phase change, high phase resolution, and low phase dispersion with frequency. Compared with other LM-enabled phase shifters, it has the advantage of easy implementation and control. This LM-based phase shifter also potentially has high power handling capability.
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More information
Accepted/In Press date: 2023
e-pub ahead of print date: 3 March 2023
Published date: 1 September 2023
Additional Information:
Funding Information:
This work was supported by the U.K. Engineering and Physical Sciences Research Council under Grant EP/V008382/1.
Publisher Copyright:
© 1963-2012 IEEE.
Keywords:
Capacitance, Dispersion, High phase resolution, linear phase modulation, liquid metal (LM), low dispersion, low insertion loss (IL), P-i-n diodes, phase compensation, Phase shifters, phase shifters, Slabs, Tuning, Varactors
Identifiers
Local EPrints ID: 481990
URI: http://eprints.soton.ac.uk/id/eprint/481990
ISSN: 0018-9480
PURE UUID: 5da237e6-89b5-4ee6-8d4a-21fb17758b02
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Date deposited: 14 Sep 2023 16:52
Last modified: 18 Mar 2024 04:13
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Contributors
Author:
Shi Yang Tang
Author:
James Churm
Author:
Yi Wang
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