摘要:

A new configuration for a flushmounted resonator antenna is presented in which the antenna is formed by a conducting cavity with a dielectric post, and radiates through an annular slot in the upper ground plane. An aperture magnetic current integral equation is used to model the slot, and the effect of the post resonator and cavity are included via Green's function techniques. The formulation is presented for the azimuthally-independent TE and TM cases. The moment method is applied to the integral equation, and the complex resonant frequencies for the antenna structure are found by searching for the zeroes of the determinant of the impedance matrix in the complex-frequency plane. The radiationQfactor, slot-field distribution, and radiation field are subsequently computed at the resonant frequency. Various TE and TM modes have been investigated for different geometrical configurations.

DOI:10.1049/ip-h-2.1992.0080

出版商:IEE    

年代:1992

数据来源: IET

摘要:

The problem of an aperture-coupled patch antenna is studied using the spectral domain technique. The general case of a slot inclined to both the feedline and the patch is considered. The equivalent circuit for the structure is obtained and the effects of various parameters, such as slot dimensions and inclination on the resonant frequency and on the input impedance, are studied. Comparison between theory and measurement shows good agreement. The analysis could be useful in designing antennas for dual frequency operation or for circular polarisation where inclined slots could be used.

DOI:10.1049/ip-h-2.1992.0081

出版商:IEE    

年代:1992

数据来源: IET

摘要:

The application of sequentially rotated feeding to dual polarisation antennas can lead not only to the well known improvements in crosspolarisation and input VSWR, but also to significantly better polarisation isolation. There are, however, many such antenna configurations that can be envisaged, and this paper clarifies the design and performance by application of firstorder analytical methods. Improved crosspolarisation suppression and polarisation isolation result for dual linear arrays, and, for dual circular antennas, crosspolarisation and input VSWR are improved. Investigation of several configurations indicates that isolation improvement cannot be achieved in the dual circular case except when the array is operated with a squinted beam. Measured results are presented that demonstrate this advance, and, together with computed results, indicate that the combination of sequential rotation and squinted beam produces dual circularly polarised arrays with many desirable performance features.

DOI:10.1049/ip-h-2.1992.0082

出版商:IEE    

年代:1992

数据来源: IET

摘要:

A novel approach is proposed for truncating finite element meshes in the analysis of open region scattering problems. In particular, fictitious absorbers are used to minimise the reflection of the scattered field from the artificial boundary enclosing the scatterer, thus simulating a free space environment. A three layered fictitious absorber model is proposed and used to demonstrate the validity of the approach.

DOI:10.1049/ip-h-2.1992.0083

出版商:IEE    

年代:1992

数据来源: IET