Triple Frequency Impedance Matching by Frequency Transformation

  • Suhash Chandra Dutta RoyEmail author


The purpose of this chapter is to bring to the attention of students and teachers of circuit theory, as well as of practising design engineers, a recently reported technique for impedance matching at multiple frequencies. This will be done through a specific example, namely that of design of a lumped network for matching a given load resistance RL to a given source resistance RS at three given frequencies ω1, ω2 and ω3. The method is based on the application of the frequency transformation technique, commonly used in analog filter design, to a basic single-frequency matching network. By comparison with the existing approach of assuming a network configuration and solving a set of simultaneous equations, as reported in a recent paper, the new method is shown to have the advantages of design by synthesis, elegance and simplicity. Further, by virtue of the synthesis approach, the method allows a number of alternative networks to be designed, so that the best one can be selected on the basis of a predetermined criterion.


Frequency transformation Network design Impedance matching Multiple frequency matching 



This work was supported by the Indian National Science Academy through the Honorary Scientist scheme. The author thanks Shoubhik Dutta Roy and Yashwant V. Joshi for their help in the preparation of this chapter. Thanks are also due to the reviewer for constructive comments.


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© Springer Nature Singapore Pte Ltd. 2020

Authors and Affiliations

  1. 1.Indian Institute of Technology DelhiNew DelhiIndia

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