On Stored Energy and Bandwidth in TEM-Mode Microwave Networks

From time domain considerations, a method is presented to calculate the energy stored in certain resonant TEM-mode microwave networks. The time average of the stored energy is then used to define an instantaneous signal bandwidth parameter through the definition of a Q or quality factor. It is demonstrated by experiment that the Q factor is inversely proportional to the rise time of the envelope of the step-modulated response of the network at resonance.