scholarly journals Rethinking Figure-of-Merits of Liquid Crystals Shielded Coplanar Waveguide Phase Shifters at 60 GHz

J ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 444-451 ◽  
Author(s):  
Jinfeng Li
Keyword(s):  
Liquid Crystals ◽  
Insertion Loss ◽  
Phase Shifter ◽  
Coplanar Waveguide ◽  
Volume Ratio ◽  
Phase Shifters ◽  
60 Ghz ◽  
Two Phase ◽  
Differential Phase Shift ◽  
Millimetre Wave

The demand for reconfigurable millimetre-wave (mm-Wave) components based on highly anisotropic liquid crystals (LC) is higher than ever before for the UK and worldwide. In this work, 60 GHz investigation on a bespoke shielded coplanar waveguide (SCPW) phase shifter structure filled with 16 types of microwave-enabled nematic LCs respectively indicates that the patterns of the device’s figure-of-merit (FoM, defined as the ratio of maximum differential phase shift to maximum insertion loss) reshuffle from those of the characterised LC materials’ FoM (defined as the ratio of tunability to maximum dissipation factor). To be more specific, GT7-29001- and MDA-03-2838-based phase shifters exhibit the highest FoM for devices, outperforming phase shifters based on GT5-28004 and TUD-566 with the highest FoM for materials. Such a mismatch between the device’s FoM and LC’s FoM implies a nonlinearly perturbed wave-occupied volume ratio effect. Furthermore, the relationship between insertion loss and the effective delay line length is nonlinear, as evidenced by measurement results of two phase shifters (0–π and 0–2π, respectively). Such nonlinearities complicate the established FoM metrics and potentially lead to a renewed interest in the selection and material synthesis of LCs to optimise reconfigurable mmWave devices, and promote their technological exploitation in phased array systems targeting demanding applications such as inter-satellite links and satellite internet.

Phased-array antennas using novel PSoC-controlled phase shifters for wireless applications

2021 ◽  
pp. 1-13
Author(s):  
Aparna B. Barbadekar ◽  
Pradeep M. Patil
Keyword(s):  
Insertion Loss ◽  
Phase Shifter ◽  
Phased Array ◽  
Phase Shifters ◽  
Control Circuit ◽  
Power Divider ◽  
Phased Array Antenna ◽  
Phased Array Antennas ◽  
Array Antennas ◽  
Low Insertion Loss

Abstract The paper proposes a system consisting of novel programmable system on chip (PSoC)-controlled phase shifters which in turn guides the beam of an antenna array attached to it. Four antennae forming an array receive individual inputs from the programmable phase shifters (IC 2484). The input to the PSoC-based phase shifter is provided from an optimized 1:4 Wilkinson power divider. The antenna consists of an inverted L-shaped dipole on the front and two mirrored inverted L-shaped dipoles mounted on a rectangular conductive structure on the back which resonates in the ISM/Wi-Fi band (2.40–2.48 GHz). The power divider is designed to provide the feed to the phase shifter using a beamforming network while ensuring good isolation among the ports. The power divider has measured S11, S21, S31, S41, and S51 to be −14, −6.25, −6.31, −6.28, and −6.31 dB, respectively at a frequency of 2.45 GHz. The ingenious controller is designed in-house using a PSoC microcontroller to regulate the control voltage of individual phase shifter IC and generate progressive phase shifts. To validate the calibration of the in-house designed control circuit, the phased array is simulated using $s_p^2$ touchstone file of IC 2484. This designed control circuit exhibits low insertion loss close to −8.5 dB, voltage standing wave ratio of 1.58:1, and reflection coefficient (S11) is −14.36 dB at 2.45 GHz. Low insertion loss variations confirm that the phased-array antenna gives equal amplitude and phase. The beamforming radiation patterns for different scan angles (30, 60, and 90°) for experimental and simulated phased-array antenna are matched accurately showing the accuracy of the control circuit designed. The average experimental and simulated gain is 13.03 and 13.48 dBi respectively. The in-house designed controller overcomes the primary limitations associated with the present electromechanical phased array such as cost weight, size, power consumption, and complexity in design which limits the use of a phased array to military applications only. The current study with novel design and enhanced performance makes the system worthy of the practical use of phased-array antennas for common society at large.

scholarly journals Analysis and Optimization of Thin-Film Ferroelectric Phase Shifters

1999 ◽  
Vol 603 ◽  
Author(s):  
R. R. Romanofsky ◽  
F. W. Van Keuls ◽  
J. D. Warner ◽  
C. H. Mueller ◽  
S. A. Alterovitz ◽  
...  
Keyword(s):  
Insertion Loss ◽  
Room Temperature ◽  
Phase Shifter ◽  
Ferroelectric Phase ◽  
Phase Shifters ◽  
Phased Array Antenna ◽  
New Type ◽  
Novel Devices ◽  
K Band

AbstractMicrowave phase shifters have been fabricated from (YBa2Cu3 O7-δ or Au)/SrTiO3 and Au/BaxSr1−xTiO3 films on LaAlO3 and MgO substrates. These coupled microstrip devices rival the performance of their semiconductor counterparts at Ku- and K-band frequencies. Typical insertion loss for room temperature ferroelectric phase shifters at K-band is ≈5 dB. An experimental and theoretical investigation of these novel devices explains the role of the ferroelectric film in overall device performance. A roadmap to the development of a 3 dB insertion loss phase shifter that would enable a new type of phased array antenna is discussed.

An Application of a Low-Loss MOD-Made BST Film Developed Especially with PLD Initial Nucleation Layer to a 20 GHz Tunable Phase Shifter

2004 ◽  
Vol 833 ◽  
Author(s):  
Minoru Noda ◽  
Daniel Popovici ◽  
Masanori Okuyama ◽  
Yoshinobu Sasaki ◽  
Makio Komaru
Keyword(s):  
Thin Films ◽  
Phase Shift ◽  
Phase Shifter ◽  
Coplanar Waveguide ◽  
Final Thickness ◽  
Nucleation Layer ◽  
Differential Phase Shift ◽  
Bst Thin Films ◽  
Main Layer ◽  
Initial Layer

ABSTRACTBarium Strontium Titanate (BST) thin films have been deposited on (100)-oriented MgO substrate by combining preparation of initial layer by Pulsed Laser Deposition and main layer by Metal-Organic-Decomposition method. Films with an initial layer of 20, 30 and 40 nm thickness and final thickness of 400, 650 and 800 nm have been obtained. Physical and dielectric properties of the BST thin films have been characterized from the viewpoint of frequency-agile micro and millimeter wave circuit applications. The results reveal that Ba0.6Sr0.4TiO3 thin films have a good crystallinity with characteristic orientation that is affected by the deposition conditions of the initial layer. Interdigital capacitor with a gap of 10 μm has been characterized and the dielectric loss and tunability are as low as 0.002 to 0.004 and 12%, respectively, at frequency of 1 MHz for the applied voltage from -/+40V to +/-40V. At microwave frequencies, classical coplanar waveguide lines formed on BST/(100)MgO were investigated. A differential phase shift of 18 degree was obtained at 20 GHz with insertion loss of about −2 dB at 60 V for Au/Cr interconnection. Finally, a 3-stage LC-ladder-type phase shifter with variable capacitors of BST thin film has been fabricated considering the experimental results obtained for the coplanar waveguide lines and a maximum phase shift of 40 degrees is obtained at 20 GHz at 60 V.

scholarly journals 5G Millimeter-Wave Beamforming System using Substrate Integrated Waveguide

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 1311
Author(s):  
Noorlindawaty Md Jizat ◽  
Zubaida Yusoff ◽  
Arevinthran A/L Nallasamy ◽  
Yoshihide Yamada
Keyword(s):  
Phase Difference ◽  
Return Loss ◽  
Phase Shifter ◽  
Transmission Efficiency ◽  
Phase Shifters ◽  
Substrate Integrated Waveguide ◽  
Two Phase ◽  
Transmission Amplitude ◽  
Wireless Signal ◽  
Hybrid Coupler

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.

scholarly journals Liquid Crystal-Based Enclosed Coplanar Waveguide Phase Shifter for 54–66 GHz Applications

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 650 ◽  
Author(s):  
Jinfeng Li ◽  
Daping Chu
Keyword(s):  
Liquid Crystal ◽  
Phase Shifter ◽  
Coplanar Waveguide ◽  
Time Domain Reflectometry ◽  
Device Fabrication ◽  
Metallic Surface ◽  
Volume Distribution ◽  
60 Ghz ◽  
Phase Tuning ◽  
Tunable Dielectrics

A 0–10 V bias voltage-driven liquid crystal (LC) based 0°–180° continuously variable phase shifter was designed, fabricated, and measured with insertion loss less than −4 dB across the spectrum from 54 GHz to 66 GHz. The phase shifter was structured in an enclosed coplanar waveguide (ECPW) with LC as tunable dielectrics encapsulated by a unified ground plate in the design, which significantly reduced the instability due to floating effects and losses due to stray modes. By competing for spatial volume distribution of the millimeter-wave signal occupying lossy tunable dielectrics versus low-loss but non-tunable dielectrics, the ECPW’s geometry and materials are optimized to minimize the total of dielectric volumetric loss and metallic surface loss for a fixed phase-tuning range. The optimized LC-based ECPW was impedance matched with 1.85 mm connectors by the time domain reflectometry (TDR) method. Device fabrication featured the use of rolled annealed copper foil of lowest surface roughness with nickel-free gold-plating of optimal thickness. Measured from 54 GHz to 66 GHz, the phase shifter prototype presented a tangible improvement in phase shift effectiveness and signal-to-noise ratio, while exhibiting lower insertion and return losses, more ease of control, and high linearity as well as lower-cost fabrication as compared with up-to-date documentations targeting 60 GHz applications.

Design & Modeling of 6-Bit Low Loss Ka Band Distributed MEMS Phase Shifter on GaAs

2011 ◽  
Vol 403-408 ◽  
pp. 4179-4183
Author(s):  
Anesh K. Sharma ◽  
Ashu K. Gautam ◽  
D.V.K. Sastry ◽  
S.G. Singh
Keyword(s):  
Phase Shift ◽  
Insertion Loss ◽  
Phase Shifter ◽  
Structural Parameters ◽  
Coplanar Waveguide ◽  
Actuation Voltage ◽  
Ka Band ◽  
Rf Systems ◽  
Total Phase ◽  
Digital Phase Shifter

This paper presents the design & modeling of distributed MEMS phase shifter for Ka band RF systems. The phase shift can be achieved by periodically placing the MEMS bridge variable capacitors as per Bragg frequency criteria on coplanar waveguide (CPW) using GaAs substrate. The EM & electromechanical simulation are carried out with various structural parameters to optimize the designs. The novelties like low insertion loss, low actuation voltage with distributed actuation pads & separate DC and RF are used to make the design unique. The EM simulations are carried out with HFSS and an insertion loss of -3.49 dB at 36GHz for a total Phase shift of 360 deg. was achieved with return loss of - 20.6 dB over a frequency band 34-38 GHz. The electromechanical simulations are carried to achieve the low actuation voltage of 10.3V. The significance of this study is the realization of the digital phase shifter through DMTL approach.

Design and Characterization of Novel Millimeter-Wave MEMS CPW Transmission Lines

2011 ◽  
Vol 204-210 ◽  
pp. 577-582
Author(s):  
Jian Ming Huang ◽  
Y. L. Zhou ◽  
H. Guo
Keyword(s):  
Transmission Lines ◽  
Microelectromechanical Systems ◽  
Coplanar Waveguide ◽  
Characteristic Impedance ◽  
Effective Permittivity ◽  
Phase Shifters ◽  
Mapping Technique ◽  
60 Ghz ◽  
Loss Reduction ◽  
Propagation Properties

The design and development of novel microelectromechanical systems’ (MEMS) coplanar waveguide (CPW) transmission lines, using microshield and groove, are presented in the paper to operate between 5–60 GHz. The quasi-static capacitances of CPW are calculated using the conformal mapping technique to express the propagation properties, i.e., the characteristic impedance and effective permittivity. Simulation results have shown a considerable loss reduction to levels that compare favorably with the conventional CPW. These transmission lines can be widely used in the development of phase shifters, filters, and antennas, because of their advantages in loss reduction and improvement in the performance.

Towards 76-81 GHz Scalable Phase Shifting by Folded Dual-strip Shielded Coplanar Waveguide with Liquid Crystals

2021 ◽  
Vol 5 (4) ◽  
pp. 14-22
Author(s):  
Jinfeng Li
Keyword(s):  
Liquid Crystals ◽  
Phased Array ◽  
Coplanar Waveguide ◽  
Phase Shifters ◽  
Phase Shifting ◽  
The Novel ◽  
Loss Reduction ◽  
Proof Of Concept ◽  
Tunable Dielectrics

Unconventional folded shielded coplanar waveguide (FS-CPW) has yet to be fully investigated for tunable dielectrics-based applications. This work formulates designs of FS-CPW based on liquid crystals (LC) for electrically controlled 0-360˚ phase shifters, featuring a minimally redundant approach for reducing the LC volume and hence the costs for mass production. The design exhibits a few conceptual features that make it stand apart from others, noteworthy, the dual-strip structure with a simplified enclosure engraved that enables LC volume sharing between adjacent core lines. Insertion loss reduction by 0.77 dB and LC volume reduction by 1.62% per device are reported at 77 GHz, as compared with those of the conventional single-strip configuration. Based on the proof-of-concept results obtained for the novel dual-strip FS-CPW proposed, this work provides a springboard for follow-up investible propositions that will underpin the development of a phased array demonstrator.

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