An all-pass topology to design a 0–360° continuous phase shifter with low insertion loss and constant differential phase shift

Purpose This paper aims to design a radio frequency micro-electro-mechanical system (RF MEMS)-based phase shifter using chamfered coplanar waveguide (CPW) transmission line (t-line) with open-circuit interdigital metal–air–metal (ID MAM) capacitors. Design/methodology/approach The proposed phase shifter achieves maximum differential phase shift with low loss at Ku band. The phase shifter is built with one switchable fixed-fixed beam (MEMS switch) on chamfered CPW t-line in series with two planar open-circuit ID MAM capacitors. An equivalent circuit model for the proposed phase shifter is derived, and its parameters are extracted using an electromagnetic (EM) solver. Findings The MEMS switch is actuated using an electrostatic method with the calculated residual stress of 44.26 MPa. The fabricated phase shifter exhibits low insertion loss, close to 0.14 dB at 17 GHz, with the maximum phase shift of 15.06°. The return loss is greater than 23 dB between 12 and 18 GHz. Originality/value This phase shifter presents a promising solution for low loss applications in the Ku band with a maximum phase shift. As the maximum phase shift of 15.06° is achieved for a unit cell with low insertion loss, the phase shifter is found to be feasible for modern electronically tunable phased arrays used for satellite communication and radar systems.

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Microwave Liquid Crystal Enabling Technology for Electronically Steerable Antennas in SATCOM and 5G Millimeter-Wave Systems

Crystals ◽

10.3390/cryst10060514 ◽

2020 ◽

Vol 10 (6) ◽

pp. 514 ◽

Cited By ~ 3

Author(s):

Rolf Jakoby ◽

Alexander Gaebler ◽

Christian Weickhmann

Keyword(s):

Liquid Crystal ◽

Phase Shift ◽

Millimeter Wave ◽

Phase Shifter ◽

Beam Steering ◽

Phase Shifters ◽

Worst Case ◽

Differential Phase Shift ◽

Digital Architecture ◽

Differential Phase

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.

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A DIGITAL FERRITE PHASE SHIFTER. A STUDY OF THE DIFFERENTIAL PHASE SHIFT IN CIRCULAR CYLINDRICAL WAVEGUIDES CONTAINING CIRCUMFERENTIALLY MAGNETIZED FERRITE RODS AND TUBES UNDER TRANSVERSE ELECTRIC MODE EXCITATION

10.21236/ad0609495 ◽

1964 ◽

Author(s):

D. M. Bolle ◽

G. S. Heller

Keyword(s):

Phase Shift ◽

Phase Shifter ◽

Transverse Electric ◽

Ferrite Phase ◽

Differential Phase Shift ◽

Differential Phase ◽

Cylindrical Waveguides ◽

Mode Excitation ◽

Electric Mode ◽

Transverse Electric Mode

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Temperature Characterization of Liquid Crystal Dielectric Image Line Phase Shifter for Millimeter-Wave Applications

Crystals ◽

10.3390/cryst11010063 ◽

2021 ◽

Vol 11 (1) ◽

pp. 63

Author(s):

Henning Tesmer ◽

Rani Razzouk ◽

Ersin Polat ◽

Dongwei Wang ◽

Rolf Jakoby ◽

...

Keyword(s):

Liquid Crystal ◽

Millimeter Wave ◽

Insertion Loss ◽

Phase Shifter ◽

Ground Plane ◽

Temperature Dependent ◽

Differential Phase ◽

Dependent Behavior ◽

The Impact ◽

Temperature Dependent Behavior

In this paper we investigate the temperature dependent behavior of a liquid crystal (LC) loaded tunable dielectric image guide (DIG) phase shifter at millimeter-wave frequencies from 80 GHz to 110 GHz for future high data rate communications. The adhesive, necessary for precise fabrication, is analyzed before temperature dependent behavior of the component is shown, using the nematic LC-mixture GT7-29001. The temperature characterization is conducted by changing the temperature of the LC DIG’s ground plane between −10∘C and 80 ∘C. The orientation of the LC molecules, and therefore the effective macroscopic relative permittivity of the DIG, is changed by inserting the temperature setup in a fixture with rotatable magnets. Temperature independent matching can be observed, while the insertion loss gradually increases with temperature for both highest and lowest permittivity of the LC. At 80 ∘C the insertion loss is up to 1.3dB higher and at −10∘C it is 0.6dB lower than the insertion loss present at 20 ∘C. In addition, the achievable differential phase is reduced with increasing temperature. The impact of molecule alignment to this reduction is shown for the phase shifter and an estimated 85% of the anisotropy is still usable with an LC DIG phase shifter when increasing the temperature from 20 ∘C to 80 ∘C. Higher reduction of differential phase is present at higher frequencies as the electrical length of the phase shifter increases. A maximum difference in differential phase of 72∘ is present at 110 GHz, when increasing the temperature from 20 ∘C to 80 ∘C. Nevertheless, a well predictable, quasi-linear behavior can be observed at the covered temperature range, highlighting the potential of LC-based dielectric components at millimeter wave frequencies.

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

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078721001094 ◽

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.

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