Ring coupler

Structure of a ring coupler

A ring coupler , also rat-race coupler or 180 ° hybrid , is an electrical component of high-frequency technology in which the sum or difference of two signals can be formed through interference .

Ring couplers are directional couplers that are characterized by good characteristics and simplicity. Their function is based on λ / 4 line transformation and a λ / 2 delay line. Directional couplers are often used as power dividers or in mixer circuits .

Separation into equal and differential mode

Scatter matrix of a directional coupler:

${\displaystyle S={\frac {-j}{\sqrt {2}}}{\begin{pmatrix}0&1&0&-1\\1&0&1&0\\0&1&0&1\\-1&0&1&0\end{pmatrix}}}$

literature

• Kai Chang, Lung-Hwa Hsieh: Microwave Ring Circuits and Related Structures . 2nd Edition. Wiley-Interscience, 2004, ISBN 978-0-471-44474-9 .
• Otto Zinke and Heinrich Brunswig: Textbook of high frequency technology . Springer, Berlin 1973 (2nd edition), ISBN 3-540-05974-1 .
• H. Meinke, FW Gundlach: Pocket book of high frequency technology. Volume 1: Basics - Components - Systems. 4th edition. Springer Verlag, Berlin / Heidelberg 1986, ISBN 978-3-642-96895-2 .

Web links

• High frequency technology II (accessed November 10, 2017)
• Broadband compensated line couplers with high directivity (accessed November 10, 2017)
• The application of the homodyne principle for network analysis in the millimeter wave range p. 89 ff. (Accessed on November 10, 2017)