Abstract: The present invention is directed to a piezo-electrically actuated membrane (ex.—a tuner) configured for use with a tunable cavity filter. The piezo-electrically actuated tuner may be formed of printed circuit board materials and may be placed over the cavities of the tunable cavity filter. Further, the piezo-electrically actuated tuner may promote high level performance of the tunable cavity filter, while allowing the tunable cavity filter to be tunable across wide bands.

Abstract: A tuner circuit includes a first IF signal generating a first oscillation signal, a local oscillator circuit outputting a local oscillator signal, a mixing circuit mixing the first IF signal and the oscillation signal to generate a second IF signal, and a first substrate on which at least the local oscillator signal is formed. The local oscillator circuit includes an oscillation circuit and a coaxial resonator connected to the oscillation circuit for correcting the influence of change in oscillation frequency owing to moisture and secular change. The coaxial resonator includes an impedance variable trimmer portion for adjusting the oscillation frequency, a central conductor provided at a fixed position with respect to the first substrate, and an insulator for providing insulation between the impedance variable trimmer and the central conductor. The impedance variable trimmer portion and the central conductor are adhered to one another via the insulator after adjusting is completed.

Abstract: Tuning elements are provided for use in varying the inductance of the oscillatory circuits of the transmitter and receiver units of garage door actuators operating at ultra-high frequencies. Each oscillatory circuit is a closed loop circuit fabricated on a printed circuit board. The closed loop circuit comprises a pair of printed circuit conductive paths having a fixed capacitor connected across one of the ends thereof and a discrete generally U-shaped wire connected across the other of the ends thereof. The conductive paths and the U-shaped wire comprise the inductor of the oscillatory circuit. By bending the discrete U-shaped wire at its connections with respect to the plane of the printed circuit board, the inductance of the oscillatory circuit in each unit can be adjusted as needed so that they both operate at the same resonant frequency.

Abstract: The invention relates to a passive reply device for use, for example, in automatic wireless transmission of multi-place numerical information between it and an active interrogation device which are movable with respect to one another, particularly for track-bound transport apparatus, which comprises a high frequency line section having a high frequency antenna at one end, and short circuited at its opposite end, and a plurality of high frequency coaxial resonators extending transversely to and carried by such line section, with a number of resonators being proportional to the number of places of the information to be transmitted. The resonators consist of individual elements which are inserted in appropriate bores of the line section with a press fit. The tuning of the individual resonators is determined by the particular shape of the bottom wall of each resonator, with the resonators otherwise being similar in construction.