Antennas, bandpass filters, nonreciprocal devices: Sect. 9.1 to 9.4

This lecture covers topics related to antennas, bandpass filters, and nonreciprocal devices. It starts with an explanation of crystal structures in ferrimagnetic materials, followed by discussions on high-frequency applications of soft ferrites. The lecture delves into antenna miniaturization, multiple domains in magnetic materials, and the precession of magnetization. It also explores high-Q microwave bandpass filters using YIG spheres, demagnetization tensor, and ferromagnetic resonance. The concept of non-reciprocal microwave devices like circulators and microwave insulators is explained, highlighting their applications in controlling power flow and isolating components in high-frequency systems.