Gokhan Mumcu

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Microfluidically repositionable metallized plates have been recently introduced as a technique to realize frequency-agile bandpass filters with low insertion loss (IL) and wideband continuous frequency tunability. This paper utilizes a hybrid (circuit and electromagnetic simulation) model for time efficient simulations and introduces fourth-order bandpass(More)
We present a measurement method to characterize low-loss engineered materials and natural uniaxial dielectrics. Our approach employs a rectangular cavity coupled with tailored finite-element simulations to accurately determine the permittivity tensors and loss tangents of material assemblies. Although similar approaches for natural crystals have been(More)
We present an antenna engineering approach to significantly improve off-axis detection properties of terahertz focal plane arrays (FPAs) behind an extended-hemispherical lens. In particular, antennas in the off-axis pixels in a large FPA were redesigned to exhibit tilted receiving patterns. The new antenna structure corrects for beam distortions in off-axis(More)
Size reduction of patch antennas by loading them with complementary split ring resonators (CSRRs) has been recently demonstrated for linearly polarized radiators. This paper demonstrates that the design approach can be extended for circularly polarized radiation by employing multiple CSRRs under the patch to generate a 900 rotationally symmetric antenna(More)
Basic microwave properties of magnetic photonic (MPC) and degenerate band edge (DBE) crystals are investigated mathematically and experimentally. Two dimensional and three dimensional models are considered demonstrating the very high sensitivity and field growth associated with these crystals. A major part of the paper deals with the development of(More)
We present a 3-D design and realization of degenerate band edge (DBE) periodic assemblies forming anisotropic photonic crystals to achieve highly directive radiation characteristics when operated close to band edge frequencies. For the design, we employ a method of moments implementation of the surface integral equation in presence of uniaxial dielectric(More)
We outline a fabrication and characterization process for composite materials exhibiting uniaxial anisotropy. Our proof-of-concept sample consists of alternating layers of high-contrast homogeneous dielectrics. We describe a finite element-based cavity measurement method to accurately characterize effects of adhesive loss in these assembled samples. In the(More)
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