Time-reversal Focus-gain Flatness of Polarization-varying Electromagnetic Fields in Rectangular Resonant Cavity

Abstract—In this work, theoretical analysis and numerical results are given for time-reversal (TR) focus gains of polarization-varying electromagnetic fields in a rectangular resonant cavity. To demonstrate the gains in different polarization states of the static transceivers and the ones of the rotatable transceivers, the 3 dB attenuation areas of TR angle gain (AG) and AG flatness are first calculated. The flat area is about equivalent to the range of two centrosymmetric octants in a three-dimensional Cartesian coordinate. Phase-frequency waterfalls verify the polarization-rotational rheology of the TR focus gain, in which uniform and smooth areas will contribute higher gain than uneven and rough areas.