Analysis of microstrip structures by numerical conformal transformations technique

Computer aided microstrip structures modeling has been performed by conformal mapping technique. A new approach to reduce the connectivity order of the original cross-section geometry of the structure is proposed. The multiply connected domain is reduced to simply connected ones by implementation of magnetic slits concept. The microstrip structures analysis is carried out by numerical conformal transformations technique realized in Schwarz–Christoffel toolbox for MATLAB. This technique is applied to the quasi-static analysis of coupled microstrip lines taking into account the conductor thickness. Described approach ensures high numerical efficiency and can be used for accurate analysis of complex microstrip structures

CAD techniques for microwave circuits

In little more than 10 years computer-aided design (CAD) of microwave circuits has moved from dumb terminals on mainframe computers to PCs, and now to powerful RISC workstations. Commercial CAD software now integrates the various stages of microwave circuit design: schematic capture, simulation and layout. This paper reviews the different CAD packages that are available for microwave circuit design. The basic principles employed in the modelling of microstrip circuits are introduced and the reasons for the extensive use of frequency-domain simulations are explored. The developments in nonlinear, electromagnetic and system-level simulation methods are described.The authors would like to acknowledge the financial support of the Engineering and Physical Sciences Research Council, and the Comisidn Interministerial de Ciencia y Technologia (CICr?‘), Spain, under the project TIC95-0983-C03-02. We would like to thank Hewlett Packard, Barnard Microsystems, Sonnet Software, Optimization Systems Associates, Kimberley Communications Consultants and Ansoft Corporation for their generous educational discounting. The assistance of Dr. D. M. Brookbanks at GEC-Marconi Materials Technology Ltd. (Caswell) is gratefully acknowledged

Impedance Transformers

Non

Millimeter-Waves Slot Array Antennas based on Gap Waveguide Technology

Recently, gap waveguide technology is introduced as a promising guiding structure for millimeter-wave systems. The conception of gap waveguide technology can be modeled for theoretical analysis by two parallel plates, a top perfect electric conductor layer and a bottom perfect magnetic conductor layer. This structure stops all modes propagating in all directions except for a quasi-TEM mode along the strip over a specic frequency band (stopband) when the gap between PEC and PMC plates is smaller than quarter wavelength at an operation frequency. Until now there are already four dierent versions of this novel conceptgroove, ridge, inverted microstrip and microstrip ridge gap waveguides. The proposed thesis mainly focuses on array antenna design based on gap waveguide technology. We present several low-prole single-layered and multilayer corporate-fed slot array antennas with high gain for the 60-GHz band and 140-GHz. The aim of this thesis is to demonstrate the advantages of gap waveguide technology as an alternative to the traditional lowloss waveguide structure to overcome the problem of good electrical contact due to mechanical assembly. Measurement results and experimental validation are provided for the presented antenna design