Miniaturized dual-band composite right/left-handed crossover

In this paper, an arbitrary dual-band and miniaturized crossover is proposed using the composite right/left-handed (CRLH) transmission structures. The proposed crossover is based on the two-section CRLH branch lines of three different characteristic impedances where one degree of design freedom can be used for implementation convenience. Combining the CRLH implementation approach with the even- and odd-mode analysis results, a simple design procedure is developed. To support our idea, a dual-band crossover operating at 0.9 GHz and 2.45 GHz was fabricated and tested. The experimental results are in good agreement with the simulated data. Compared to the reported dual-band crossovers based on the printed-circuit-board (PCB) technology, our presented crossover shows a significant size reduction by about 59% with respect to the smallest footprint found in the literature.