Microstrip Antennas Of Arbitrary Shape Research Articles

A novel technique for analysis of electromagnetic scattering from microstrip antennas of arbitrary shape

A new numerical procedure is developed for the solution of the electric field integral equation (EFIE) for arbitrary-shaped microstrip structures. This approach is superior over conventional EFIE techniques particularly in the low-frequency region or where the structure to be analyzed is electrically small. A pair of new basis functions is presented which are essential to the solution in the entire frequency range of interest. The new basis functions decompose the surface current density into divergenceless and curl-free parts which essentially get decoupled at the very low end of the frequency spectrum. Typical numerical results are presented for certain examples to illustrate the difference in the results between the two methods.

Via Hole and Parasitically Coupled Microstrip Antennas of Arbitrary Shape in Multi-Layered Substrates

ABSTRACT Microwave antenna performance optimization may be achieved by shaping the antenna properly, as well as with the correct antenna excitation design. This article presents the theoretical development of an algorithm which is very suitable for the design of microstrip antennas of arbitrary shape in multi-layered substrates. It includes the design of the antenna excitation either through parasitic coupling, or through a via hole transition from a microstrip line. The algorithm is applied for the design of a circularly polarized notched ring microstrip antenna coupled parasitically to a microstrip transmission line. The performance of via hole excitation of a rectangular patch antenna is also discussed.

Analysis of Coaxially Fed Microstrip Antennas of Arbitrary Shape with Thick Substrates

Arbitrarily shaped, coax-fed microstrip patch antennas with substrates that may be electrically thick are studied using a mixed-potential integral equation approach. Vector basis functions defined over triangular elements are used to approximate the current distribution on the conducting patch. Rigorous and simplified models of the probe-to-patch junction, compatible with the triangular element model of the microstrip patch, are implemented and their relative merits are discussed. Two models of the coaxial probe, differing in accuracy and complexity, are also implemented and their ranges of validity are examined. Input impedance data for several microstrip patch antennas of different shapes, computed using different coax feed models, are presented and compared with measured results.

Spectral dyadic Green's function formulation for planar integrated structures

The problem of the complete determination of the dyadic spectral Green's function for an integrated planar structure with a grounded dielectric slab has been considered and solved in a rigorous way by using the spectral theory of the electromagnetic field. The reciprocity theorem and the geometrical symmetry of the structure have demonstrated the different roles played by the independent terms of the spectral Green's function in the evaluation of the electromagnetic characteristics of the grounded slab excited with a general source. Furthermore, an equivalent circuit representation of the structure, allowing a noteworthy simplification in the determination of the total power, has been obtained. These equivalent circuits and the derived spectral Green's function presented here can be used to analyze and design microstrip antennas of arbitrary shape with a general type of loading, such as matched or unmatched loads, parasitic, and shorting pins. >

Exact expression for stored energies in the cavity volume of microstrip antennas

Exact expressions for the stored electromagnetic energies in planar microstrip antennas of arbitrary shape are derived as simple functions of the normal electric field. These expressions provide a considerable reduction of computation time and also great simplifications at the stage of problem formulation.