This page examines rectangular cavity resonators, which are hollow conducting structures operating at discrete resonant frequencies determined by their dimensions. The fundamental mode TE101 marks the...This page examines rectangular cavity resonators, which are hollow conducting structures operating at discrete resonant frequencies determined by their dimensions. The fundamental mode TE101 marks the lowest frequency, with energy decay characterized by a quality factor Q. Physical alterations of the resonator, influenced by electromagnetic forces, affect resonant frequency and energy storage.