Abstract: A coaxial microwave device, such as a microwave switching device, for example, having improved thermal and power handling characteristics. At least one thermally conductive short-circuit element is located between inner (input and output) and outer conductors of the microwave coaxial or switching device. Consequently, heat losses generated in the inner conductors are conductively channeled away from heat sensitive materials. Typically, quarter-wavelength elements provide a thermal path to reduce heat buildup, thus enabling the microwave coaxial device or switching device to operate at higher RF power levels without overstressing components or materials. However, short circuit elements having element lengths other than one-quarter-wavelength may be employed to offset mismatches in a transmission line, for example. Furthermore, the short circuit elements may be used singularly or in pairs to provide for improved thermal and power handling characteristics in the devices in which they are used.

Abstract: In each of the sense amplifiers of a DRAM, the common source terminal of pull-down transistors which are connected to a bit line pair is connected to a discharge line through first and second current paths. One end of the discharge line is grounded. The first and second current paths are provided with first and second switches, respectively. The first and second switches are independently controlled by a different signal. The first current path is further provided with a third switch. The third switch is turned on when the potentials of both of the bit lines are greater than a threshold, and turned off when one of the potentials is not greater than the threshold.

Abstract: An intermediate frequency filter for an intermediate frequency used in the receiver section of a digital radio communications apparatus is composed of an amplitude-flat ceramic filter incorporating two ceramic resonators, a buffer means and a single tuning circuit having the center frequency thereof within the bandwidth of the amplitude-flat ceramic filter, all being connected in series with each other. The center frequency of the single tuning circuit and Q are adjusted to approximate the amplitude characteristic of the intermediate frequency filter to that of TBT filter (0.4.ltoreq.parameter m.ltoreq.1.0).

Abstract: An electromagnetic noise filter has a plurality of U-shaped wires passing through a ferrite core. Some of the wires are singly fitted in throughholes, whereas other wires are commonly fitted in throughholes. The wires can be interconnected to provide for impedance to both differential-mode and common-mode noise.

Abstract: A transmission line structure (100) is provided which includes a resonator (110) having open ends (118) disposed on a substrate (130). The first resonator (110) includes a control voltage terminal (116) which is positioned at a point along the length where a zero potential exists at resonant frequency. Transmission zero frequency is tuned by means of a varactor (150) which is coupled to the control voltage terminal and receives a control voltage for controlling the zero frequency.

Abstract: A read only memory device comprises a memory cell array, a selector unit interconnecting one of the memory cells to an input node of a sense amplifier unit for producing a read-out signal at a read-out node, a reference unit for producing a reference signal with an intermediate voltage level between voltage levels corresponding to logic "1" bit and logic "0" bit, and a voltage comparator coupled to the sense amplifier unit and the reference unit, wherein the sense amplifier unit has a load transistor continuously supplying current to the read-out node, a transfer gate transistor for interconnecting the input node and the read-out node under the control of an inverting amplifier coupled to the input node, and a charging transistor for providing an auxiliary current path to the read-out node upon rapid decay in voltage level at the read-out node, thereby causing the read-out signal to quickly become stable.

Abstract: A dielectric filter including a plurality of coaxial type dielectric resonators having outer conductors and inner conductors is arranged so that the outer conductors are connected to each other. Also included in the dielectric filter are central conductors arranged to be brought into contact with the inner conductors of said plurality of coaxial type dielectric resonators and a dielectric substrate having thereon a plurality of substrate conductors whose number at least corresponds to the number of the plurality of coaxial type dielectric resonators, and input/output terminals provided on said dielectric substrate. The central conductors are respectively coupled to the substrate conductors provided on the dielectric substrate and inductance elements are connected to the substrate conductors which are positioned at both sides.

Abstract: Previously it was not possible to realize a ceramic duplex filter using a single monolithic ceramic block, because the isolation between the transmitter branch and the receiver branch could not be made sufficiently high. A duplex filter (1) can be realized in a single ceramic block by making, between its filters (A and B), a strip-like area (9) on the non-coated surface (5) of the ceramic block, due to which the electric and magnetic coupling between the resonators (R.sub.4, T.sub.1) of filters (A and B) on each side of the area can be adjusted to almost zero. This "electric partition" (9) provides a sufficient isolation between the filters of each branch.

Abstract: This composite electronic part comprises a dielectric layer on which earth electrodes are formed, a dielectric layer on which conductive lines are formed, and a dielectric layer on which electronic parts are pattern-formed. A plurality of the dielectric layers are so laminated that the dielectric layer with the earth electrodes is disposed next to the dielectric layer with the conductive lines. These conductive lines and earth electrodes form strip lines. A short-stub or an open-stub is formed by connecting one end of the conductive line to the earth electrode or opening that one end. A composite electronic part is obtained by connecting the short-stub, open-stub, and the electronic parts.

Abstract: A concept previously used for providing anti-rotational locking of complementary threaded devices is utilized in a RF tuning cavity to minimize anti-microphonic disturbances of the prior art caused by inconsistent ohmic contact between the prior art adjustable length threaded portions. The use of a resilient locking strip embedded longitudinally into the threads of an adjustable resonator provides substantially constant electrical or ohmic contact between the two threaded portions so as to maintain a standing wave in the tuning element. The longitudinal design of the locking strip is such as to prevent or minimize movement of the extremity of the threaded resonator which movement can also effect the resonant frequency.

Abstract: The present invention is to overcome a problem of a variation in a resonant frequency of a microwave stripline filter which may occur at a change of temperature during when the microwave stripline filter is operated. The microwave stripline filter has resonator electrodes (3 and 4) with a predetermined pattern provided between a pair of dielectric substrates (1 and 2), one of the dielectric substrates is formed by ceramic material whose temperature coefficient of resonant frequency is negative, and the other substrate is formed by a ceramic material whose temperature coefficient of resonant frequency is positive, which results in that the mutual temperature dependency to the resonant frquency in the paired dielectric substrates can be cancelled, and thus it is possible to feasibly hold the temperature coefficient of the filter device to zero. The stripline filter according to the present invention can conveniently utilized as a band-pass filter for miniature electronic circuits.

Abstract: In a directional coupler having four input/output terminals in a planar circuit using strip lines or microstrip lines, a quarter-wavelength line is connected between first and third terminals, and between second and fourth terminals, respectively, and furthermore between first and second terminals, and between third and fourth terminals, individually, a branch line is connected, having a length which is (2N+1)/4 wavelength, cascading (2N+1) pieces of quarter-wavelength lines (where N is a positive integer). These (2N+1) quarter-wavelength lines composing the branch lines are set so that lines of high characteristic impedance and lines of low characteristic impedance appear alternately.

Abstract: A dielectric resonator oscillator having a resonant structure connected to an amplifier the output of which is fed back to the input of the resonant structure. The resonant structure includes a metal cavity in which a dielectric disk is centrally mounted by a low-loss dielectric post. A pair of microstrip transmission lines extend into the cavity to provide energy outputs and inputs. Dielectric and conductive tuning screws are mounted on the cavity walls. Electrical tuning is provided via a varactor diode whose bias is adjustable. The diode may be connected in series or parallel with the microstrip transmission line.

Abstract: A tunable bandstop/bandpass filter particularly suitable for use in duplex applications where the transmit and receive bands are closely located, comprises two or more reactively coupled quarter wavelength resonators e.g. dielectric resonators. One end of each resonator is coupled to ground potential. The opposite (open-circuit) end of the resonators is coupled to adjacent resonators via coupling capacitors. Voltage controlled tuning means, e.g. a varactor and series connected capacitor, are coupled in parallel to the open circuit end of each of the resonators respectively. The stopband/passband of the filter can thus be adjusted by varying the voltage applied to the tuning means. Additionally, in the case of a bandpass filter a tunable zero (or "notch") may be introduced into the transmission response by including varactors coupled in series to the open-circuit end of the resonators.

Abstract: A dielectric filter includes a unitary dielectric block formed of a uniform, single dielectric material and having electrically conductive metallized patterns formed on front, rear and lateral walls, and on an outer bottom surface thereof. A plurality of coaxial dielectric resonators each including an open end and a central conductor are longitudinally arranged along the center of a top surface of the block and are spaced apart a predetermined distance. Frequency adjusting patterns are formed on the top surface of the block, each frequency adjusting pattern extending around an open end of a respective one of the resonators. Coupling amount adjusting patterns are also disposed on the top surface of the block, each connected to the front and rear walls and disposed between adjacent ones of the frequency adjusting patterns. At least one additional coupling amount adjusting pattern is disposed on the top surface of the block.

Abstract: An LC filter is provided which includes a first conductive sheet, a first dielectric sheet laminated on the first conductive sheet, a second conductive sheet laminated on the first dielectric sheet, a second dielectric sheet laminated on the second conductive sheet, a third conductive sheet laminated on the second dielectric sheet, and a third dielectric sheet laminated on a third conductive sheet formed as an integral body which has the first, the second and the third conductive sheets and the first, the second and the third dielectric sheets, are coiled. The first and the second conductive sheets are respectively provided with input terminals and output terminals.

Abstract: An electron tube for achieving high power at high frequency with high efficiency, including an input coupler, a ribbon-shaped electron beam and a traveling wave output coupler. The input coupler is a lumped constant resonant circuit that modulates a field emitter array cathode at microwave frequency. A bunched ribbon electron beam is emitted from the cathode in periodic bursts at the desired frequency. The beam has a ribbon configuration to eliminate limitations inherent in round beam devices. The traveling wave coupler efficiently extracts energy from the electron beam, and includes a waveguide with a slot therethrough for receiving the electron beam. The ribbon beam is tilted at an angle with respect to the traveling wave coupler so that the electron beam couples in-phase with the traveling wave in the waveguide. The traveling wave coupler thus extracts energy from the electron beam over the entire width of the beam.

Abstract: A YIG notch filter using full RF coupling loops and having a notch filter center frequency tunable as high as 18 GHz comprising a plurality of undoped YIG spheres of much smaller volume than used in the prior art and linearly arranged in a air gap. The spheres are suspended in cavities in a nonmagnetic block which are spaced much more closely than in the prior art. The 50 ohm stripline impedance inverters formed on a substrate and connecting the RF coupling loops of the spheres used in the prior art are eliminated. The quarter-wavelength impedance inverter function necessary to fabricate a notch filter is implemented by using the RF coupling loops themselves and measuring the distance from centerline to centerline of adjacent RF coupling loops. Twin insulated wires with up to one diameter separation for the RF coupling loops are preferred with the wires soldered together between the spheres.

Abstract: A dielectric heat-radiator of a thin plate form is pressed against one side of a dielectric resonator and a dielectric support is bonded to an opposite side of the dielectric resonator. The heat-radiator is supported elastically with nuts and springs by support columns each fixed at one end to a metal baseplate. The resonant frequency is adjusted by processing the electromagnetic energy transmitted through the dielectric heat-radiator. In consequence, heat generated in the dielectric resonator, upon having a high-power high-frequency signal applied thereto, is allowed to propagate efficiently to the dielectric heat-radiator having a high heat conductivity through the wide contact surface between the dielectric resonator and the heat-radiator.

Abstract: A system for coupling two resonating cavities, where the coupling system provides a form of bandpass or bandstop filtering about the desired frequency mode and helps suppress undesired modes about the desired frequency mode and higher order modes. The system for coupling the two resonating cavities includes a tuned evanescent iris, where the tunability of the iris is provided by at least one tunable resonating capacitance element embedded in the iris.