Metin Sengul

Design of Practical Matching Networks With Lumped Elements Via Modeling

It is a common practice to utilize commercially available software tools to design matching networks for wireless communication systems. Most of these tools require a properly selected matching network topology with good initial element values. Therefore, in this paper, a practical method is presented to generate matching networks with initial element values. In the implementation process of the proposed method first, the driving point immitance data for the matching network is obtained in a straight forward manner without optimization. Then, it is modeled as a realizable bounded-real input reflection coefficient which in turn yields the desired matching network with reasonable element values. Eventually, the initial design is improved by optimizing the performance of the matched system employing the commercially available computer-aided design (CAD) packages. An example is given to illustrate the utilization of the proposed method. It is shown that new method provides excellent results as a front-end when utilized together with CAD tools.

Broadband Decoupling and Matching of a Superdirective Two-Port Antenna Array

Decoupling and matching networks may be used to improve the performance of compact antenna arrays where mutual radiator coupling has caused a degradation of the diversity capabilities. A popular network consists of a 180deg rat-race directional coupler, which decouples the antenna ports, followed by impedance matching networks at each port. Researchers, however, usually neglect the presence of losses both within the antenna array and the decoupling and matching network. For this reason, we have built various narrowband and broadband matching networks and compare their performances with the help of calibrated far-field measurement data.

Design of Practical Broadband Matching Networks With Lumped Elements

It is always preferable to use commercially available software tools to design broadband matching networks for microwave communication systems. However, for these tools, the matching network topology and element values must be selected properly. Therefore, in this paper, a practical method is presented to generate matching networks with good initial element values. Eventually, the performance of the designed matching network is optimized by employing the commercially available computer-aided design (CAD) tools. An example is given to illustrate the utilization of the proposed method. It is shown that the proposed method provides very good initials for CAD tools.

Synthesis of Cascaded Lossless Commensurate Lines

A scattering transfer matrix factorization based algorithm for cascaded lossless commensurate line synthesis is presented. The characteristic impedances of the extracted commensurate lines and the reflection factors of the remaining networks are formulated in terms of reflection factor coefficients of the whole circuit. There is no need to use root search routines so as to cancel common terms, to get degree reduction. The formulation of the method is explained, and an example is included, to illustrate the implementation of the synthesis algorithm.

Construction of Lossless Ladder Networks With Simple Lumped Elements Connected Via Commensurate Transmission Lines

In this work, an algorithm to design lossless ladder networks with simple lumped elements connected via commensurate transmission lines is proposed. After giving the algorithm, a lumped-element low-pass Chebyshev filter was transformed to its mixed-element counterpart to illustrate the utilization of the algorithm. The filter, designed for a frequency band around 1 GHz, was fabricated and experimentally characterized. We find very good agreement between measured and simulated transducer power gain over the entire frequency band of interest.

Broadband Equalizer Design with Commensurate Transmission Lines via Reflectance Modeling

In this paper, an alternative approach is presented, to design equalizers (or matching networks) with commensurate (or equal length) transmission lines. The new method automatically yields the matching network topology with characteristic impedances of the commensurate lines. In the implementation process of the new technique first, the driving point impedance data of the matching network is generated by tracing a pre-selected transducer power gain shape, without optimization. Then, it is modelled as a realizable bounded-real input reflection coefficient in Richard domain, which in turn yields the desired equalizer topology with line characteristic impedances. This process results in an excellent initial design for the commercially available computer aided design (CAD) packages to generate final circuit layout for fabrication. An example is given to illustrate the utilization of the new method. It is expected that the proposed design technique is employed as a front-end, to commercially available computer aided design (CAD) packages which generate the actual equalizer circuit layout with physical dimensions for mass production.

Design of Practical Broadband Matching Networks With Mixed Lumped and Distributed Elements

Computer-aided design (CAD) tools are always preferred for designing broadband matching networks. However, these tools give excellent results when the suitable matching network topology and initial element values are provided. Therefore, in this brief, a new initialization algorithm is proposed to get suitable network topology and element values for CAD tools. Then, the power transfer capability of the matching network can be improved by using any CAD tool. It is clear from the example studied that the new method generates excellent initials.

Transfer matrix factorization based synthesis of resistively terminated LC ladder networks

In this paper, a transfer matrix factorization based synthesis algorithm for resistively terminated low-pass LC ladder networks is presented. In the algorithm, component value of the extracted element and the reflection factor of the remaining network are well formulated in terms of reflection factor coefficients of the whole network. An example is presented to exhibit the application of the proposed synthesis algorithm.

Power transfer networks at RF frequencies: new design procedures with implementation roadmap

The purpose of this work is to provide the necessary background to design wide-band power transfer two-ports, or so-called broadband matching networks, at radio frequencies for wireless communication systems. The importance of the topic stems from the recent advances in the conceptual design and manufacturing technologies of the next-generation wireless and mobile communication systems, which will operate over ultra-wide frequency bands. In fact, for all communication systems, construction of wide-band power transfer networks is essential. Therefore, in this manuscript, new procedures to design broadband matching network are covered, and a design roadmap is given with relevant recommendations. As an example, the design of a compensation network for a RF switch matrix covering the band 17...23 GHz is presented, which employs the roadmap described in this work

Design of impedance matching network for B&K 8104 hydrophone via Direct Computational Technique for underwater communication

Underwater acoustic communication is a rapidly growing field of applied research and is a technique of sending and receiving message below water. There are several ways of doing such communication but the most common one is realized by using transducers. In underwater acoustic communication, one of the most important problems is driving the transducers with matched network. In this study, design of impedance matching network for B&K 8104 hydrophone that can be used for underwater communication was performed via Direct Computational Technique (DCT).