A novel design of ultra-high impedance transforming ratio quad-band matching network

In this article, a novel design of quad-band matching network (QBMN) with ultra-high impedance transforming ratios (UHTRs) is proposed and designed based on ABCD matrix method. The QBMN is capable of matching a very large real load impedance at four different frequencies simultaneously. The quad-band structure is composed of -section with series connected coupled lines at each port. The design formulas of QBMN are derived analytically to obtain the quad-band operation. In order to validate the proposed idea, three examples of QBMN for different load impedances (500, 1000, and 1500 ) are considered. Finally, two QBMNs with transforming ratios of 10 and 20 are fabricated and demonstrated. For both the prototypes, the measured S-11 is better than 15 dB at all working frequencies. The experimental performances are consistent with the simulated results.