Physical and technical bases of using ferromagnetic resonance in hexagonal ferrites for electromagnetic compatibility problems

Frequency-selective measurement of microwave signal parameters based on application of gyromagnetic converters has proven advantageous for the research of microwave radiation over a wide spectrum (several octaves) in multisignal regime in microwave path and for the solution of a number of electromagnetic compatibility (EMC) problems. The measurement frequency band can be enlarged to millimeter-waves with application of monocrystal hexagonal ferrite resonators (HFR) having high internal magnetic fields. Millimeter-wave field interactions with the HFR having alternating resonance frequency are analyzed. This is useful for millimeter-wave signal modulation and demodulation. The analysis is based on the solution of magnetization vector motion equation of the uniaxial spherical HFR with time-varying bias magnetic field or angle of the HFR orientation (for modulation problem) and with amplitude-modulated microwave signal action (for demodulation problem). The novel principle of the HFR frequency-selective measuring system based on automodulation design is discussed