Abstract: A coaxial resonator which can be electrically connected to an inductance or similar electric element easily to reduce the number of work steps for mounting and the number of parts, and a dielectric filter and a dielectric duplexer which include a resonator and which can be more compact and installed in a diminished space. The coaxial resonator includes a dielectric block having a through-bore extending through opposite end faces thereof, and a conductor layer formed over an outer peripheral surface of the block except one end face thereof and over a block inner surface defining the through-bore for causing electromagnetic waves to resonate within the dielectric block. A lead-equipped electric element has its lead inserted in and fixed in the through-bore and electrically connected to the conductor layer over the bore-defining inner surface with a braze filler metal or electrically conductive adhesive.

Abstract: The invention provides a three-stage surface acoustic wave filter of the ladder type wherein the resonance frequency difference &Dgr;f2 between the resonance frequency frs2 of a serial resonator in an intermediate stage and the resonance frequency frp2 of a parallel resonator therein is set at a value greater than the resonance frequency difference &Dgr;f1 (&Dgr;f3) between the resonance frequency frs1 (frs3) of a serial resonator in each of front and rear stages and the resonance frequency frp1 (frp3) of a parallel resonator therein, whereby the filter is given a widened pass band while reliably retaining satisfactory characteristics comparable to those of conventional surface acoustic wave filters of small pass band width. The desired filter exhibiting such performance is available within a shorter period of time and with reduced labor.

Abstract: A surface acoustic wave filter device comprising a plurality of surface acoustic wave filters 3, 51, 52 formed on a common piezoelectric substrate 13, each of the surface acoustic wave filters comprising, as arranged on a surface of the piezoelectric substrate 13, a plurality of interdigital electrodes 31-33, 53-55, 56-58 and grating reflectors 61, 67, 64, 65, 66 at opposite sides of the electrode arrangement with respect to the direction of propagation of surface acoustic waves. The two surface acoustic wave filters 3, 51 which are adjacent to each other share one grating reflector 67 as the grating reflector to be disposed at one of the opposite sides of the electrode arrangement of each of the adjacent filters, whereby the device can be made more compact than conventionally without greatly altering the design of the filters or impairing the performance thereof.

Abstract: The invention provides a process for producing solid electrolyte capacitors by forming a dielectric oxide film and a first cathode layer of solid conductive substance over the surface of an anode body of valve metal, and forming a second cathode layer of conductive high polymer on the first cathode layer by electrolytic oxidative polymerization. The second cathode layer is formed by immersing in the electrolyte the anode body formed over the surface thereof with the oxide film and the first cathode layer, feeding a positive voltage with an external electrode piece in contact with the first cathode layer in the electrolyte, and shifting the feeding point at a predetermined time interval.

Abstract: A dielectric filter including at least three coaxial dielectric resonators of predetermined size which are bonded as arranged side by side. The resonators serving respectively as an input stage and an output stage are each formed with an external connection electrode positioned on the peripheral surface other than the adjoining surface in proximity to an exposed end face and insulated from an outer conductor layer. An inner conductor layer of the resonator serving as an intermediate stage is removed over only a suitable region from an exposed end face thereof so as to approximately match the resonance frequency of the intermediate-stage resonator to the resonance frequency of the input-stage and the output-stage resonators. The dielectric filter may include at least three coaxial dielectric resonators which are bonded as arranged side by side.

Abstract: The invention provides a process for producing solid electrolyte capacitors by forming a dielectric oxide film and a first cathode layer of solid conductive substance over the surface of an anode body of valve metal, and forming a second cathode layer of conductive high polymer on the first cathode layer by electrolytic oxidative polymerization. In forming the second cathode layer, the pH of the electrolyte to be used for electrolytic oxidative polymerization is maintained within a predetermined range by adding an acid or alkali to the electrolyte. Since the pH of the electrolyte remains substantially unaltered by the polymerization according to the invention, the electrolyte is repeatedly usable while permitting the resulting second cathode layers to retain the desired electric conductivity.

Abstract: A process for producing a dielectric filter by bonding coaxial dielectric resonators of predetermined size as arranged side by side. The process comprises forming interstage coupling windows by removing an outer conductor layer from the same region of each of adjoining surfaces of the resonators to be adjacent to each other, and bonding the resonators as arranged side by side in proximity to each other on a smooth-surfaced table with an electrically conductive bonding material applied to at least one of the outer conductive layers remaining on the adjoining surfaces.

Abstract: The object of the invention is to provide a process for producing an organic solid electrolyte capacitor which is diminished in leakage current, and an apparatus for use in practicing the process. The process includes the steps of completing a capacitor element by forming a dielectric oxide film over an anode body of valve metal and subsequently forming a cathode layer of solid conductive organic material over the oxide film, subjecting the capacitor element to an aging treatment, and forming a shell around the capacitor element.

Abstract: An antitheft system embodying the invention comprises an alarm unit 2 attached to a commodity for producing an alarm on receiving a detection signal or an alarm activating signal while stopping the alarm on receiving an alarm stopping signal, and a signal generator provided on a cashier's counter for producing alarm activating signals and alarm stopping signals alternately. When the commodity is handed by the customer to the clerk at the cashier's counter, with the alarm unit 2 attached to the commodity, the alarm unit 2 intermittently produces an alarm on receiving alarm activating signals and alarm stopping signals alternately, thereby enabling the clerk to reliably recognize that the alarm unit 2 is attached to the commodity. When the clerk thereafter removes the alarm unit 2 from the commodity, the production of alarm is forcibly ceased.

Abstract: This invention relates to solid electrolyte capacitors and is intended to decrease the contact resistance between the body of the capacitor and lead frames and the internal resistance of these components The invention provides a process for producing a solid electrolyte capacitor by forming a dielectric oxide film on an anode body of valve metal, forming a cathode layer of solid conductive substance on the oxide film to prepare a capacitor element, coating the cathode layer of the capacitor element with a carbon layer, coating the carbon layer with a silver paste layer to prepare a capacitor body, and bonding a lead frame to the silver paste layer of the capacitor body with a silver adhesive. While the capacitor element coated with the carbon layer and a silver paste are being vibrated relative to each other, the capacitor element is dipped in the silver paste and withdrawn therefrom in the direction of the vibration, whereby the carbon layer is coated with the silver paste layer.

Abstract: A nullification device of the invention comprises a nullifying signal generator 15 for producing a nullifying signal, and a controller 14 for measuring a predetermined period of time and on/off-controlling a mode change switch 16 provided between the signal generator 15 and a transmitting antenna 18. On the other hand, an activation device comprises a generator 23 for producing an activating signal for the nullification device. The activation device and the nullification device have connection terminals a, b and a', b', respectively, where the devices are in contact with each other, with the nullification device placed in a accommodating recess in the activation device.