Abstract: A transmission line cavity comprises an outer conductor and a center conductor. The cavity is in combination with a source, such as a power tube, for establishing electromagnetic waves within the cavity. The impedance of the center conductor may be changed, for example by changing the series inductance, to vary the resonant frequency of the cavity.

Abstract: The disclosure is directed to an improved coaxial resonator such as a .lambda./4 coaxial resonator or the like to be used for an electrical filter or oscillator, etc. which operates, for example, in UHF ranges. The coaxial resonator includes a stator electrode provided on the resonator main body, a rotor of a dielectric material formed with a rotor electrode confronting the stator electrode and rotatably mounted on the resonator main body so as to vary capacity between the stator electrode and the rotor electrode through rotation of the rotor for alterations of the resonance frequency.

Abstract: A coaxial-structure filter which utilizes a flat depression machined in the bottom surface of the filter cover as the resonant frequency determining element in a resonant cavity is disclosed. The depression is directly above the cavity resonator post when the cover is installed and provides a lumped capacitance from the post to the cover. The resonator post is machined flush with the resonator's top wall thereby placing the critical mechanical dimensions associated with the frequency determining elements in a more desirable location than prior methods (i.e., in the filter cover).

Abstract: A microwave filter comprising within a conductive casing, a plurality of resonant transmission lines arranged parallel between opposed end walls of the casing, a plurality of shielding members each located between adjacent transmission lines, and a capacitive interstage coupling member disposed transverse to the transmission line. The interstage coupling member comprises a dielectric member and a plurality of conductive regions arranged successively thereon so as to establish capacitive coupling between adjacent conductive regions. Each transmission line is connected at one end to a side wall of the casing and supported at the other end by the dielectric member in electrical contact with a respective one of the conductive regions, whereby the interstage coupling between the transmission lines is provided by the capacitively coupled conductive regions.

Abstract: The components of a transistor oscillator are mounted on an end cap rotatably mounted on the outer tube of a cavity resonator which stabilizes the oscillator. The intensity with which a high frequency is applied to the cavity resonator is adjustable by rotation of the end cap.