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

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.

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Design & Simulation of Low Loss 5-Bit Ku Band Switched Line MEMS Phase Shifter on Gaas

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.403-408.5330 ◽

2011 ◽

Vol 403-408 ◽

pp. 5330-5334

Author(s):

Anesh K. Sharma ◽

Ashu K. Gautam ◽

D.V.K. Sastry ◽

S.G. Singh

Keyword(s):

Phase Shift ◽

Return Loss ◽

Phase Shifter ◽

Rf Mems ◽

Structural Parameters ◽

Actuation Voltage ◽

Low Loss ◽

Total Phase ◽

Phase Shift Error ◽

Ku Band

As the requirement for the low loss phase shifter increases, so does the development of RF MEMS as a solution. This paper presents the design & simulation of Switched line MEMS phase shifter for Ku band using GaAs substrate. The phase shift can be achieved by varying the lengths in delay path to the reference path for the same phase velocity. The electromagnetic & electromechanical simulations were carried out with various structural parameters to optimize the design. The novelties like low insertion loss, low actuation voltage with distributed actuation pads for DC and RF are used to make the design unique. The EM simulations are carried out using 3D simulator HFSS and a phase shift of 172.6 deg./dB for a total Phase shift of 348.75deg was achieved with return loss of 15.5dB over a frequency band from 16-18 GHz and a phase shift error less than ±2 degree in the 32 states. The electromechanical simulations are carried to achieve the low actuation voltage of 15.3V. These parameters make these suitable for the Phased array applications [1, 2].

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First Demonstration of a Periodically Loaded Line Phase Shifter Using BST Capacitors

MRS Proceedings ◽

10.1557/proc-603-37 ◽

1999 ◽

Vol 603 ◽

Cited By ~ 3

Author(s):

Amit S. Nagra ◽

Troy R. Taylor ◽

Padmini Periaswamy ◽

James Speck ◽

Robert A. York

Keyword(s):

Phase Shift ◽

Insertion Loss ◽

Parallel Plate ◽

Room Temperature ◽

Phase Shifter ◽

X Band ◽

Fabrication Procedure ◽

Room Temperature Operation

AbstractPeriodically loaded line phase shifter circuits using voltage tunable BaSrTiO3 (BST) parallel plate capacitors have been demonstrated at X-band. The first such phase shifter circuit was capable of 100° of phase shift with an insertion loss of 7.6 dB at 10 GHz. Subsequently, the monolithic fabrication procedure was refined resulting in an improved phase shifter circuit with 200° of phase shift and an insertion loss of 6.2 dB at 10 GHz. In addition to promising loss performance (32°/dB) at 10 GHz, the circuits reported here have several desirable features such as moderate control voltages (20 V), room temperature operation, and compatibility with monolithic fabrication techniques.

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

MRS Proceedings ◽

10.1557/proc-833-g1.5 ◽

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.

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