Passive Adaptive Intensity High-Pass Devices for Nonreciprocal HPM Prevention

This article presents a series of intensity high-pass devices (IHPDs) that are designed and investigated to prevent the propagation of high-power microwaves (HPMs) in RF front-end systems. The IHPDs function as a band-stop filter for low-intensity waves and a bandpass filter for high-intensity waves. By combining an IHPD, a circulator, and a matched load, an intensity-dependent nonreciprocal component (IDNC) is created. The IDNC exhibits unidirectional transmission characteristics with high power backward input, thus achieving HPM protection. This article investigates and verifies the mechanisms and designs of IHPDs through measurements to meet various performance requirements. First, circuit models for diodes, circuit units, and IHPDs are established successively. Next, a standardized design procedure is presented, which clearly outlines the steps from specifications to implementation. The optimal values of the circuit components are determined by comparing them with the results of circuit and full-wave simulations. The measured results, including the
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-parameters, bandwidths, and thresholds, closely match the designed results. This method provides a new perspective and is suitable for high-power in-band full-duplex (IBFD) applications.