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ABSTRACT: This paper is focused on the study of the tunability of planar composite right/left handed (CRLH) transmission lines based on the combination of open split ring resonators (OSRRs) and open complementary split ring resonators (OCSRRs), and its application to microwave devices. The tunability is achieved by means of Barium-Stronium-Titanate (BST) thick films, which change the electrical properties of the structures through the application of an static electric field. Some potential applications such as phase shifters or tunable band pass filters are presented, where a frequency tunability of 36.6% is obtained.
Microwave Symposium Digest (MTT), 2011 IEEE MTT-S International; 07/2011
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ABSTRACT: A low-cost phased-array antenna at 10 GHz is presented for a scan angle of ±50°. The array employs continuously tunable phase shifters based on a screen printed barium-strontium-titanate thick-film ceramic. Due to the use of artificial transmission line topology, the proposed phase-shifter design has a very compact size (3 mm × 2.8 mm) for 342° total phase shift. In the frequency range from 8 to 10 GHz, it exhibits a figure of merit >;52°/dB, which is among the best of phase shifters based on ferroelectric thick films. In a prototyped phased array, the RF circuit consists of a feeding network, phase shifters, and antenna elements, which are integrated into one planar metallization layer. Furthermore, a simple way for routing bias lines for phase shifters is demonstrated using high resistive electrodes. Using screen printed thick films and applying a simplified fabrication process for the RF and bias circuitry can reduce the total expense of phased arrays considerably.
IEEE Transactions on Microwave Theory and Techniques 06/2011; · 1.85 Impact Factor
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M. Gil, C. Damm,
M. Sazegar,
M. Maasch,
A. Giere,
M. Schü̈ler,
F. Aznar,
A. Vélez,
J. Bonache,
R. Jakoby,
F. Martín
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ABSTRACT: This study shows recent results in the implementation of electrically reconfigurable structures based on sub-wavelength resonators implemented by means of ferroelectric materials. Barium-Strontium-Titanate thick films are employed as part of the substrate to implement electrically tunable split-ring resonators and open complementary split-ring resonators. Different structures have been fabricated proving the viability of this strategy for the implementation of reconfigurable structures. The achieved frequency shift reaches 12.6%. A parameter extraction method has been applied to study the effects of the modification of the dielectric permittivity of the ferroelectric material on the structure properties and its frequency response.
IET Microwaves Antennas & Propagation 03/2011; · 0.68 Impact Factor
