摘要:

Experimental measurements have been made of the capacitive effects of a gap in a wide microstrip line with a thick, low permittivity substrate. The results reveal negligible fringing capacitance at each edge of the gap. Derived values of the coupling capacitance across the gap are also presented.

DOI:10.1049/ip-h-2.1989.0011

出版商:IEE    

年代:1989

数据来源: IET

摘要:

An extended analysis for the radiation characteristics of a closed-ring microstrip antenna is presented. The general closed form expression for the total energy stored is derived by utilising the properties of the cylindrical functions. Known closed form expressions for its radiation field based on the cavity model are also used to derive general expressions for the radiated power in a converging series form, by utilising the properties of the Gauss' hypergeometric function and by using Euler's transformation. The expressions are used to set the relation between efficiency and bandwidth, taking into account ohmic and dielectric losses. It is shown that different structures can have the same performance at the critical frequency. At the higher frequencies, narrower ring structures can have smallQ-factors, high gain and large bandwidth. This is opposite to the behaviour of the structures at low frequencies.

DOI:10.1049/ip-h-2.1989.0012

出版商:IEE    

年代:1989

数据来源: IET

摘要:

A circularly polarised printed slot array antenna (CP-PSAA) is conveniently obtained by changing the position of slots in the microstrip line slot array antenna proposed in the previous work. The fundamental structure of the CP-PSAA consists of a group of slots arranged in a ground plane which are excited through a microstrip line. The basic design of this antenna is described. Performance parameters such as axial ratio, input characteristics and pattern quality are examined with some experiments, and it is found that the CP-PSAA will lend itself to realising wideband printed arrays with high-performance.

DOI:10.1049/ip-h-2.1989.0013

出版商:IEE    

年代:1989

数据来源: IET

摘要:

The complex boundary element equation for the solution of the characteristic impedance of an arbitrarily shaped TEM transmission line, based on the Cauchy integral theorem for analytical complex variable functions is derived in the paper. By using the CVBEM a great reduction in the computational time can be achieved by omitting the numerical quadrature, which is otherwise necessary in real variable boundary element equations. Equations for the constant element method, the linear element method and some numerical results that relate to several typical transmission lines are presented.

DOI:10.1049/ip-h-2.1989.0014

出版商:IEE    

年代:1989

数据来源: IET

摘要:

We present two algorithms to calculate the modal quasistatic parameters of a general multiconductor planar structure (multistrip or multislot) embedded in one of the interfaces of a multilayered substrate with arbitrary anisotropy in the transverse plane. Variational techniques in the spectral domain are used and a detailed study of trial functions is carried out. Very accurate results for both well known structures and new design data are presented to show the efficiency and generality of the method.

DOI:10.1049/ip-h-2.1989.0015

出版商:IEE    

年代:1989

数据来源: IET

摘要:

A first-order model of the symmetrical five-port waveguide junction with metallic post and inductive diaphragms is developed. Supplementing the theoretical data thus obtained with empirical adjustments, a suitable prototype is designed for use as the essential component of a six-port reflectometer capable of yielding optimum performance.

DOI:10.1049/ip-h-2.1989.0016

出版商:IEE    

年代:1989

数据来源: IET