摘要:

The paper describes a cheap method for absolute temperature compensation of a tunable resonant cavity which exhibits linearity in tuning, at least over a narrow but useful frequency range, and for which a linear law relates the frequency change to the temperature change of at least 30°C around the reference temperature. The technique considers compensated resonant cavities constructed from common conductors. Theory and practice show that a high degree of reduction in temperature dependency of the resonant frequency can be achieved.

DOI:10.1049/ip-h-2.1985.0084

出版商:IEE    

年代:1985

数据来源: IET

摘要:

A simple method is described for analysis of a slot antenna on dielectric substrate of finite thickness. The method consists in using several transformations for reducing the original structure to approximately complementary/dual structure; i.e. to a cylindrical dipole of circular cross-section with a coaxial magnetic cover. The structure thus obtained is then analysed using well-known methods. A model of the slot on dielectric substrate fed by a coplanar waveguide was realised, and experimental results for slot impedance agreed well with the theory.

DOI:10.1049/ip-h-2.1985.0085

出版商:IEE    

年代:1985

数据来源: IET

摘要:

It is proposed that the slots of a longitudinally slotted horn be filled with a dielectric material. This is shown to considerably reduce the required slot depths for achieving low crosspolarisation; thus more feasible and economic design of such a horn is possible. Design curves for the modal propagation constants of the first two modes against the frequency, the dielectric constant of the slot filling material and the geometrical constants of the horn are presented. The co- and cross-polar radiation patterns are calculated, and it is found that peak crosspolar level < − 50 dB can be achieved at certain frequencies and a level < − 30 dB can be achieved over about 13% bandwidth.

DOI:10.1049/ip-h-2.1985.0086

出版商:IEE    

年代:1985

数据来源: IET

DOI:10.1049/ip-h-2.1985.0087

出版商:IEE    

年代:1985

数据来源: IET