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Substrate integrated waveguides (SIWs) have been preferred over conventional micro-strip and coplanar transmission lines owing to their minimal conductor losses especially at millimeter-wave frequencies. These have been extensively used in different active and passive circuits (M. Bozzi, A. Georgiadis, IET, 5, 909–920, 2011). Different configurations of SIW-based filters have also been presented,...
Variable capacitors are a key component in Radio Frequency Micro Electro-Mechanical Systems (RF MEMS). They comprise fixed and flexible electrodes. Deformation, or actuation, of the flexible electrode changes the capacitance of the capacitor. This way, electrical properties of high frequency circuits can be modified. Traditionally, variable capacitors are based on a planar layout architecture, while...
Polyester-styrene polymer composites of high permittivity ceramic nano powders (barium titanate) are fabricated and electrically measured for antenna applications. It is shown that the usage of high permittivity ceramic contents can increase the relative permittivity of the composites to around 10 at microwave frequencies. The Polyester-styrene composite material preparation technique is described...
A novel approach for effectively feeding a wide-band dielectric resonator antenna (DRA) of very low-permittivity is presented in this paper. It is shown that a tapered microstrip line with optimized length and width can provide excellent impedance matching. The impedance bandwidth of the antenna (S11 < −10 dB) associated with single resonance mode is over 35%. A minimum reflection coefficient...
Photoresist-based polymer-ceramic composites are proposed for single exposure, direct deep X-ray lithography fabrication of dielectric resonator antenna arrays in thick layers. DRA elements based on fabrication in a 2.3 mm thick SU-8/alumina microcomposite layer are combined in a 3×3 antenna array to demonstrate an increase in gain from 5.5 to 13.6 dB at 23 GHz. A second ground plane can be used to...
X-ray lithography fabrication has the ability to produce high-aspect ratio structures with smooth side walls and precise lateral details. Air-gap Standing Parallel Strips waveguide and related microwave circuits and antennas are a new approach to employ these features, providing low loss microwave circuits that are highly attractive for high frequency and millimeter-wave applications. In this work,...
In this paper, radiation properties and impedance characteristics of lithographically patterned SU-8 structures are discussed. X-ray lithography fabrication process and excitation method of SU-8 resonator antennas are reviewed. Wide band operation is examined by merging the resonances of the SU-8 resonator antenna and an aperture antenna. Reflection coefficient measurement of fabricated antennas is...
EPON™ SU-8 is a negative-tone photoresist which has been extensively used in UV and Xray lithography for fabrication of various mechanical and optical structures. In this work SU-8 is studied as a polymer binder for antenna applications. It is reinforced with different weight percents of alumina (AI2O3) micropowder. Up to 2 mm thick rectangular slabs are lithographically produced with optimized X-ray...
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