Compact filtering power divider with good frequency selectivity and wide stopband based on composite right‐/left‐handed transmission lines

Abstract

ABSTRACTA novel compact power divider with good frequency response and wide stopband based on composite right‐/left‐handed (CRLH) transmission line is presented in this article. To provide bandpass‐filtering frequency response, the bandpass filtering circuits is applied to this power divider using the CRLH resonators. The bandpass filtering circuit can generate two transmission zeros at the lower and upper stopband and have a wide upper stopband. Besides, the phase shift of the CRLH filter is tuned to be 90° for the sake of replacing the conventional quarter‐wave length branch line in the power divider. Moreover, the capacitive coupling between the input and output of the resonator is used simultaneously to generate three additional transmission zeros beside the passband edges. Then, the frequency selectivity of the power divider is greatly improved. A resistor is placed at the center of the symmetric plane to produce good isolation between the two outputs. A filter‐integrated power divider operating at 3.7 GHz is implemented. Good agreement between the simulated and measured results is observed. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2122–2125, 2014