R. Jedlicka

Bio: R. Jedlicka is an academic researcher from New Mexico State University. The author has contributed to research in topics: Coupling & Patch antenna. The author has an hindex of 2, co-authored 3 publications receiving 189 citations.

Measured mutual coupling between microstrip antennas

Abstract: Mutual coupling between L -band rectangular, nearly square, and circular microstrip antennas has been investigated experimentally by a series of measurements of the S -parameters. The mutual coupling level decreases monotonically with increasing separation between elements with the E -plane coupling down 20 dB and the H -plane coupling down 25 dB for typical adjacent element spacings. For 1/16 in and 1/8 in substrates at L -band the predominant coupling mechanism is via the space wave since the surface wave is shown experimentally to be small.

Efficient computational models of electromagnetic coupling through general tortuous-path, narrow-slot apertures into shielded systems

Abstract: Electromagnetic coupling can adversely impact a multitude of applications. The primary coupling issues are electromagnetic compatibility and interference, either intentional or unintentional. The functionality of the systems involved, which typically consist of numerous subsystems operating concurrently, can be characterized in terms of their susceptibility, vulnerability and survivability in the electromagnetic environment in which they are expected to operate. Coupling through unforeseen apertures such as the tortuous-path, lapped seam depicted in the paper into conducting cavities containing multiple thin conducting elements is the major thrust of this work. To model realistic coupling problems, it is necessary to develop a model which includes a three-dimensional representation of the slot/cavity/wire configuration. Specifically, such a model should incorporate narrow slot apertures having depth, loss and gaskets, bolt loads, backed by arbitrarily-shaped cavities, filled with inhomogeneous, lossy dielectrics, and thin wires in arbitrary configurations. The widely varying scales in such a system provides a challenge to a numerical model in terms of both accuracy and efficiency. This is especially true in a development engineering environment in which the engineer typically has a desk-top workstation on which to perform an analysis.

Microstrip antenna technology

Abstract: A survey of microstrip antenna elements is presented, with emphasis on theoretical and practical design techniques. Available substrate materials are reviewed along with the relation between dielectric constant tolerance and resonant frequency of microstrip patches. Several theoretical analysis techniques are summarized, including transmission-line and modal-expansion (cavity) techniques as well as numerical methods such as the method of moments and finite-element techniques. Practical procedures are given for both standard rectangular and circular patches, as well as variations on those designs including circularly polarized microstrip patches. The quality, bandwidth, and efficiency factors of typical patch designs are discussed. Microstrip dipole and conformal antennas are summarized. Finally, critical needs for further research and development for this antenna are identified.

Microstrip antennas integrated with electromagnetic band-gap (EBG) structures: a low mutual coupling design for array applications

Abstract: Utilization of electromagnetic band-gap (EBG) structures is becoming attractive in the electromagnetic and antenna community. In this paper, a mushroom-like EBG structure is analyzed using the finite-difference time-domain (FDTD) method. Its band-gap feature of surface-wave suppression is demonstrated by exhibiting the near field distributions of the electromagnetic waves. The mutual coupling of microstrip antennas is parametrically investigated, including both the E and H coupling directions, different substrate thickness, and various dielectric constants. It is observed that the E-plane coupled microstrip antenna array on a thick and high permittivity substrate has a strong mutual coupling due to the pronounced surface waves. Therefore, an EBG structure is inserted between array elements to reduce the mutual coupling. This idea has been verified by both the FDTD simulations and experimental results. As a result, a significant 8 dB mutual coupling reduction is noticed from the measurements.

Input impedance and mutual coupling of rectangular microstrip antennas

Abstract: A moment method solution to the problem of input impedance and mutual coupling of rectangular microstrip antenna elements is presented. The formulation uses the grounded dielectric slab Green's function to account rigorously for the presence of the substrate and surface waves. Both entire basis (EB) and piecewise sinosoidal (PWS) expansion modes are used, and their relative advantages are noted. Calculations of input impedance and mutual coupling are compared with measured data and other calculatious.

RF MEMS and their applications

Abstract: Preface. Microelectromechanical Systems (MEMS) and Radio Frequency MEMS. MEMS Materials and Fabrication Techniques. RF MEMS Switches and Micro Relays. MEMS Inductors and Capacitors. Micromachined RF Filters. Micromachined Phase Shifters. Micromachined Transmission Lines and Components. Micromachined Antennae. Integration and Packaging for RF MEMS Devices. Index.

Computational Electromagnetics for RF and Microwave Engineering

Abstract: The numerical approximation of Maxwell's equations, Computational Electromagnetics (CEM), has emerged as a crucial enabling technology for radio-frequency, microwave and wireless engineering. The three most popular 'full-wave' methods - the Finite Difference Time Domain Method, the Method of Moments and the Finite Element Method - are introduced in this book by way of one or two-dimensional problems. Commercial or public domain codes implementing these methods are then applied to complex, real-world engineering problems, and a careful analysis of the reliability of the results obtained is performed, along with a discussion of the many pitfalls which can result in inaccurate and misleading solutions. The book will empower readers to become discerning users of CEM software, with an understanding of the underlying methods, and confidence in the results obtained. It also introduces readers to the art of code development. Aimed at senior undergraduate/graduate students taking CEM courses and practising engineers in the industry.