摘要:

The behaviour of waveguiding structures loaded with solid-state semiconductors under an external DC magnetic field is considered. The solid-state physical basis for the semiconductor magnetoplasma effect is presented, including carrier transport, Drude model, linearised governing equations and conductivity tensor. The resulting asymmetric anisotropy in the complex-element permittivity tensor can be exploited to generate nonreciprocal propagation. Dynamic numerical methods used to obtain the propagation characteristics of various waveguiding structures, including rectangular, circular and planar (i.e. microstrip, coplanar, slotline and finline) are presented. The frequencies covered extend from about about 9 GHz in the microwave regime up through the millimetre, submillimetre and optical regions.

DOI:10.1049/ip-h-2.1993.0025

出版商:IEE    

年代:1993

数据来源: IET

摘要:

The paper presents a historical review of gyroelectric devices. It presents the theoretical and experimental performances of nonreciprocal devices using semiconductor materials, and introduces a theoretical approach to circulators using high-mobility layers, applicable to MMIC technology.

DOI:10.1049/ip-h-2.1993.0026

出版商:IEE    

年代:1993

数据来源: IET

摘要:

Sophisticated communication and radar systems in the submillimetre wavelength bands will only be realised when the designers have access to the same diversity of devices available at lower frequencies such as circulators, differential phase shifters and nonreciprocal isolators. Below 100 GHz these devices depend on high quality ferrites. However, despite considerable investment in research and development, ferrites materials have not been realised that will yield acceptable performance at higher frequencies. This prompted the author to start investigating the possibility of using surface magnetoplasmons on high quality lightly doped semiconducting substrates as the vehicle for the design of nonreciprocal components in the submillimetre regime. This paper chronicles investigations pursued during the period 1976–1986, principally by faculty and students at Brown University and Lehigh University, into the behaviour of surface magnetoplasmons in a variety of canonical structures germane to nonreciprocal devices in the millimetre and submillimetre wavelength ranges. Interest focused on performance characteristics for such devices as differential phase shifters and nonreciprocal isolators. Critical to obtaining acceptable performance parameters such as insertion loss are, of course, the loss characteristics of the semiconducting materials. The latest results, based on studies of our canonical device models and presuming the use of the best available materials, indicate that acceptable device performance should be attainable. Results are presented that show insertion loss as well as isolation ratio for representative nonreciprocal isolator structures and the attained differential phase shift per unit insertion loss for a canonical differential phase shift configuration.

DOI:10.1049/ip-h-2.1993.0027

出版商:IEE    

年代:1993

数据来源: IET

摘要:

The method of lines has been proved to be very efficient for calculating the characteristic properties of quasiplanar waveguides used in integrated microwave and millimetre wave circuits or in integrated optics. In the paper, it is shown how the method of lines can be applied to the analysis of quasiplanar waveguides with gyroelectric or gyromagnetic layers. The procedure described is very general. All directions of magnetisation parallel to one of the axes are taken into account.

DOI:10.1049/ip-h-2.1993.0028

出版商:IEE    

年代:1993

数据来源: IET

摘要:

The full-wave spectral domain approach together with the EBM method is used to analyse the nonreciprocal wave propagation in laterally open boundary planar structures with a multilayered gyroelectric substrate. A study of the nonreciprocal surface slow waves appearing in an externally magnetised MIS line is presented. This work also presents the ability of that configuration to support both slow wave and nonreciprocal effects with reasonable losses. Various numerical results are presented that show the dependence of the propagation parameters on the magnitude and orientation of the biasing magnetic field. It is shown that external control of the magnitude of the biasing field permits equalisation of the modal phase velocities in a pair of coupled strips on a magnetised MIS configuration.

DOI:10.1049/ip-h-2.1993.0029

出版商:IEE    

年代:1993

数据来源: IET

摘要:

The propagation characteristics of a 70 GHz slow surface wave in a transversely magnetised, partially filled, parallel-plate, solid-plasma waveguide have been investigated experimentally using n-InSb as the plasma material to which a pulsed current was applied. The surface-wave resonant magnetic field increased substantially with an increase in the applied current. Subsequently, a variation of the electron density of the plasma material with the current was determined by measuring the reflection from the plasma slab. The results indicate that the variation of the propagation characteristics is primarily explained by the variation of the electron density in the plasma material, and that the propagation characteristics of the slow surface wave in the above mentioned plasma waveguide can be controlled electronically by applying a current to the solid-plasma material.

DOI:10.1049/ip-h-2.1993.0030

出版商:IEE    

年代:1993

数据来源: IET

摘要:

The behaviour of the TM01mode found in the azimuthally magnetised, semiconductor-filled, coaxial waveguide and the transversely magnetised parallel-plate configuration has been rigorously analysed. Investigation of the Poynting vector shows field displacement in both guides, with annular and laminar regions of negative average power density. The radial displacement of the electromagnetic fields in the coaxial waveguide gives rise to double-value phase constants below cut-off and nonreciprocal phase behaviour. This does not occur in the parallel-plate structure owing to its symmetry. Attenuation due to electron collisions was calculated for the TMommodes in the parallel-plate case. This has implications for the attenuation expected of the TMommodes in the coaxial-waveguide case. Gallium arsenide and indium antimonide proved promising in the frequency range 50–150 GHz when cooled to 77 K. For nonreciprocal devices in MMICs it appears that low doping concentrations will be required.

DOI:10.1049/ip-h-2.1993.0031

出版商:IEE    

年代:1993

数据来源: IET

摘要:

Propagation characteristics and modal field distributions are obtained for an embossed rectangular waveguide employing isotropicn-type semiconductor material. A finite-element formulation utilising eight-noded quadrilateral elements was used to derive the dispersion spectrum with spurious solutions rigorously eliminated. The canonical model analysed here employs surface plasmons in a doped semiconducting medium as interface guided waves in the near millimetre wave range. Such structures have potential use in the guidance and control of millimetre waves and have applications in the design of planar quasioptical integrated devices.

DOI:10.1049/ip-h-2.1993.0032

出版商:IEE    

年代:1993

数据来源: IET

摘要:

A rigorous, versatile and general formulation for the analysis of propagation characteristics of rectangular biaxial anisotropic dielectric waveguide structures with arbitrarily varying indices of refraction profiles is presented. In this formulation the finite-difference method is used for the numerical solution of the wave equation, written in terms of the transverse components of the magnetic field. As a result, a conventional eigenvalue problem is obtained without the presence of the spurious modes (observed in previous formulations), due to the implicit inclusion of the divergence of the magnetic field equal to zero. The theoretical development was used to solve particular problems and the results have shown agreement with those available using other methods.

DOI:10.1049/ip-h-2.1993.0033

出版商:IEE    

年代:1993

数据来源: IET

摘要:

A method for the description of the fields in finlines on anisotropic substrates is presented. The method also allows the complex tensor character of all material parameters and the influence of second-order effects, such as metallisation thickness, to be taken into account. The principal boundary value problem can be described with the help of a relatively small eigenmatrix and so the numerical treatment demands little work. Numerical and measurement results are presented, and discussed, for the transmission properties and for the field and power distributions. Furthermore, a suitable definition of the characteristic impedance is introduced, having in mind CAD applications. Design procedure and measurement characteristics for nonreciprocal elements are also included.

DOI:10.1049/ip-h-2.1993.0034

出版商:IEE    

年代:1993

数据来源: IET