High-Power Filtering Switch With Low Loss and High Isolation Based on Dielectric Resonator

Abstract

In this paper, a novel method for designing high-power filtering switches using dielectric resonators (DRs) is presented for the first time. The filtering switches consist of DRs and printed circuit boards. The latter are embedded in the metal cavity to enable the integration of p-i-n diodes. The ON- and OFF-states are realized by controlling the p-i-n diodes which are put in the feeding lines or nonresonance nodes (NRNs). Electromagnetic field properties of the DR (at TE $_{11\delta }$ mode) and feeding line (or NRN) are studied and the coupling between them is investigated for guiding coupling control. In the ON-state, the filtering switches are equivalent to bandpass filters with no signal passing through the p-i-n diodes, which avoids additional loss introduced by p-i-n diodes and attains high power handling capability. In the OFF-state, the proposed filtering switches offer enhanced isolations by controlling the coupling of the filtering circuits, which differs from the conventional switches by turning off transistors or diodes. For demonstration, a DR-based filtering single-pole single-throw switch and a filtering single-pole double-throw switch are implemented. High selectivity, low ON-state loss and high OFF-state isolation are observed. The measured $\text{P}_{\mathrm {1dB}}$ is larger than 80 W, featuring high power handling capability.