Jorge A. Ruiz-Cruz

Computer Aided Design of Wideband Orthomode Transducers based on the Bøifot Junction

A CAD tool based on the Boslashifot junction is proposed for the design of wideband orthomode transducers (OMTs). It has two interesting features. First, the OMT routing branches use well-known waveguide elements, such as truncated E-plane bends, which can be efficiently analyzed by mode-matching (MM) methods and can achieve wideband performance. Second, a MM technique is presented for the four-port Boslashifot junction, which provides its generalized multimode characterization. As a result, the whole OMT is segmented into different regions, yielding an efficient CAD tool for its optimum design. The analysis method and the designed OMT have been validated with other numerical methods and experimental results

Computer Aided Design of Waveguide Devices by Mode-Matching Methods

1.1 Waveguide devices and CAD tools Technology is one of the key issues in the hardware design at the microwave and millimetre wave band. Its selection depends on many factors such as bandwidth, physical size, losses, power handling capability and cost. This has led to many different transmission media for implementing circuits and systems; the planar and the waveguide technologies are two representative examples. The main advantages of planar structures are their small size and simple manufacturing. In addition, they can be easily integrated with Microwave Integrated Circuits (MIC) and Monolithic Microwave Integrated Circuits (MMIC). The microstrip transmission line is a common example of this technology, where circuits are made by printing a metallic strip on a dielectric substrate supported by a ground plane. On the other hand, waveguide devices (the type of components which will be discussed in this chapter) are constructed on metallic pipes that may have many forms. The electromagnetic waves are confined to the interior of the waveguiding structure. In contrast to planar devices, they are more cumbersome and bulkier. Their main advantage is their high power handling capabilities and high quality factor (Q), which leads to electric responses with lower insertion losses than planar technology components. In satellite applications, their robustness also becomes an advantage. One aspect that has significantly modified the design of advanced waveguide components during the last decades has been the evolution of software modeling and Computer Aided Design (CAD) tools. Traditionally, the analysis of waveguide devices (such as couplers, filters or multiplexers) was based on approximate equivalent circuits made up of transmission lines to represent waveguiding regions and lumped elements (inductors, capacitors, transformers, resistors, etc.) to model dissipative effects and discontinuities between different transmission media. Most of the equivalent circuits for waveguide problems were developed at the MIT 6

Waveguide filters with elliptical function response: Overview and results of different implementations: Research Articles

This paper presents recent advances in the areas of modeling, design, and fabrication of microwave filters for space applications. A fast and accurate hybrid analysis method, combining boundary integral resonant mode expansion (BI-RME) and integral equation (IE) techniques, is described. Several filters used in satellite payloads have been successfully designed, manufactured, and measured.

Design of Self-Equalised Elliptic Filter Channels in Ka-Band Implemented in Rectangular H-Plane Waveguide

In this article, a systematic design procedure for the design of self-equalised elliptic filters in H-plane configuration is presented. Such a configuration in tends to be an alternative to the classical dual-mode circular waveguide configuration in Ka band, with the aim in mind of reducing cost and computation time. In order to decrease the insertion loss the TE105 will be used. A sixth order filter with two transmission zeros at finite real frequencies and two zeros for equalisation has been designed, manufactured and measured. The results make clear the validity of the proposed configuration