摘要:

Using Silicon as the substrate material, silicon monolithic millimetre-wave integrated circuit (SIMMWIC) oscillators and receivers are successfully realised. For the coplanar oscillators, a slot is used as the resonant structure in which a monolithically integrated IMPATT diode, selectively grown by silicon molecular beam epitaxy (Si-MBE), acts as the negative resistance device. Pulsed and CW operation of the planar oscillators is achieved in the 90 GHz region. The output power is radiated directly from the resonant slot. Complete receivers, with monolithic Schottky diodes together with the antenna, are integrated on a single chip. The suitability of the chips for near-range measurements is pointed out.

DOI:10.1049/ip-h-2.1992.0039

出版商:IEE    

年代:1992

数据来源: IET

摘要:

Scattering by an electrically small bianisotropic sphere embedded in a gyroelectromagnetic uniaxial medium is considered. A simple scattering formalism is presented which can be applied to a wide class of media, artificial and natural, which are covered by the general constitutive relations used. The equivalent polarisability dyadics have been obtained in the long wavelength approximation. The results are pertinent to some dilute discrete random composites.

DOI:10.1049/ip-h-2.1992.0040

出版商:IEE    

年代:1992

数据来源: IET

摘要:

It is demonstrated that the type of equivalent network of a resonator depends only on the coupling configuration. Based on experimental results, electric or magnetic coupling is considered, and two particular cases are described. In the case of a thick iris, a rigorous equivalent network is proposed; and in the case of a probecoupled cavity, a new theoretical approach is presented.

DOI:10.1049/ip-h-2.1992.0041

出版商:IEE    

年代:1992

数据来源: IET

摘要:

Waves in some sophisticated waveguiding structures, filled with magnetised ferrite, are investigated. Anisotropic boundary conditions are supposed to be valid on some of the walls of the waveguides, whence the results allow, for instance, an analysis of ferrite-filled corrugated waveguides and microstrip lines with corrugated strips. For solving the related electromagnetic problems, a new approximate technique — averaging method — is used. The main idea is to average field inside a waveguide, assuming that the components tangential to the interfaces are locally quasistatic. The present technique can be used when one of the transversal dimensions of a waveguide is much smaller than the wavelength in that direction. The results could help to develop different devices, such as controlled phase-shifters and isolators.

DOI:10.1049/ip-h-2.1992.0042

出版商:IEE    

年代:1992

数据来源: IET

摘要:

The power combining efficiency of ann-way power combiner is calculated in terms of the scattering matrix of the combiner network, and the factors affecting it are identified. The maximum value of the combining efficiency is then deduced, for a given power combiner with known network parameters, under various sets of constraints on the amplitudes and phases of the signals being combined. In each case, the signal conditions needed to achieve the maximum efficiency are determined.

DOI:10.1049/ip-h-2.1992.0043

出版商:IEE    

年代:1992

数据来源: IET

摘要:

The capacitive equivalent circuit and the modal equivalent lengths of the symmetric broadside coupled microstrip open-end discontinuity are calculated in the case in which the conducting strips are embedded in a multilayered dielectric medium. The Galerkin method in the spectral domain is applied to solve the excess charge densities existing on the conducting strips of the discontinuity both in even and odd modes of excitation. Results are presented for broadside coupled microstrip open ends in conventional, suspended and inverted configurations.

DOI:10.1049/ip-h-2.1992.0044

出版商:IEE    

年代:1992

数据来源: IET

摘要:

The problem of a radiating slot on the ground plane of a microstripline is solved using the spectral domain approach. The equivalent circuit for the configuration is obtained, and the elements are determined using the integral transformation techniques. Effects of various parameters, such as slot dimensions and inclination with the feedline, are studied. Results are compared with measurements, and reasonable agreement is obtained. The results and the approach should find useful applications in integrated circuits and aperture-coupled patch antennas.

DOI:10.1049/ip-h-2.1992.0045

出版商:IEE    

年代:1992

数据来源: IET

摘要:

The full-wave spectral domain technique is used for the first time to analyse the single and covered triangular patch antennas fed by the coaxial probe. The equilateral triangular patch antenna fed by a probe along the patch median was analysed and its input impedance and radiation patterns are presented. The effects of flat radomes on these parameters are studied. To avoid excessive computation time, three sets of basis functions representing the approximate current distributions on the patch are introduced. Merits of each set of basis functions are discussed. Various tests were made to establish the validity of the basis functions, including comparisons of the results against those obtained by the cavity model and against those of some experimental observations.

DOI:10.1049/ip-h-2.1992.0046

出版商:IEE    

年代:1992

数据来源: IET

摘要:

Novel nonreciprocal components based on hollow ferrite discs, i.e. ferrite ring resonators, are discussed. Some three-port and four-port components are analysed, and some design guidelines are presented. It is shown that a ring structure requires a smaller diameter and ferrite thickness than a disc structure for the same frequency. A ring also provides another variable in design and permits ports to be connected to the inside as well as the outside. Novel components and increased component density may therefore be possible at the expense of bandwidth.

DOI:10.1049/ip-h-2.1992.0047

出版商:IEE    

年代:1992

数据来源: IET

摘要:

To assess the performance of electrically small antennas, the two most fundamental antennas, namely electric and magnetic dipoles, have been chosen for examination of their performance in a superconducting environment. Aspects of the two antennas and their matching networks that are discussed include efficiency,Q, input impedance, power gain, power handling and signal/noise ratio. Both transmitting and receiving performances are considered. Finally, experimental results for loop and dipole antennas constructed out of YBCO wire are presented and compared with their supercooled copper counterparts. In this, they show a significant improvement in efficiency.

DOI:10.1049/ip-h-2.1992.0048

出版商:IEE    

年代:1992

数据来源: IET