TABLE OF CONTENTS Resonant circuits and resonators are important circuit elements in radio-frequency engineering. A resonant circuit is formed by a capacitor and an inductor connected in parallel or in series. As components in active and passive circuits, resonant circuits and resonators allow a selective transmission or blocking of signals. In oscillators these components serve as the frequency-determining elements.
A circuit element with a single port is called a one-port. Figure 9.1 shows the schematic drawing and the equivalent circuit of a one-port. Incident and reflected waves are related to a given transverse plane of reference. The signal at the port is described either by the complex amplitudes a and b of the incident and scattered waves or by the voltage V and current I. If the relation between V and I or a and b, respectively, is known, the one-port is defined as a circuit element. If the relation between V and I or a and b, respectively, is linear, the one-port is called a linear one-port. The complex power P c flowing into the one-port is given by
| (9.1) |  |
The integration is performed over the cross-sectional area A of the waveguide port in the plane of reference. With (4.19), (8.9a), (8.9b) and (8.22a) we obtain a complex power P c flowing into the one-port:
| (9.2) |  |
The real part...
