Matsushita Electric Industrial Co., Ltd.

Hiroyuki Yabuki

Mitsuo Makimoto

Morikazu Sagawa

Michiaki Matsuo

Kazuaki Takahashi

Munenori Fujimura

Noriaki Saito

Yoshito Shimizu

Isao Ishigaki

Yoshito Nakanishi

Motoi Ohba

Haruyoshi Endo

Masao Nakagawa

Resonatorsandare able to oscillate horizontally and vertically to substrate. Resonatoris primarily composed of a supporting portion in stationary contact with substrate, a movable portion including a contact surface making contact with resonatorand a contact surface making contact with electrode, and a crossing portion that couples the supporting portion and movable portion. Electrodeis disposed in the direction in which resonatoris spaced apart from resonator. Electrodeis disposed in the direction in which resonatoris spaced apart from resonator. Electrodeis disposed in a position that causes resonatorto generate electrostatic force in a direction different from the direction of both forces of attraction acting between resonatorsandand between resonatorand electrode

Micro device

In a cascade amplifier, the collector of a first transistor with a grounded emitter and the emitter of a second transistor are connected. A third transistor has the base grounded at radio frequency, the emitter connected to the base of the first transistor, and the collector connected to the collector of the second transistor. A fourth transistor connected to the emitter of the third transistor works as a constant current source. A bias changeover circuit supplies base biases of these transisiors. In this constitution, by using the bias changeover circuit for changing over the bias depending on the cut-off condition of the first transistor, the gain is changed over by making either the cascade amplifier or the third transistor operate.

Amplifier and radio communication apparatus using the same

A filter of microwave and millimetric bands with spurious characteristic controlled is disclosed. A filter circuit on a top surface of the substrate including resonators electromagnetically resonating and coupled at a resonance frequency at a microwave band and a millimeter wave band, for filtering an input signal from the connectors through the resonator and outputting the filtered signal through the connector. The filter circuit is contained in a metal box including a top plate confronting the top surface and the filter circuit, side walls, and a bottom plate. An inside surface of the top plate has a shape other than a flat plane to control the spurious characteristic, that is, a protrusion. The bottom plate of the metal box may be coalesced. The spurious characteristic may be controlled by a hollow portion in the top plate. The protruding portion may be provided to the side walls. The spurious frequency may be controlled by a dielectric plate in the space in the shielding. Microstrip line resonators, patch resonators, or dielectric resonators are used as the resonator.

Filter with spurious characteristic controlled

A dielectric filter includes a dielectric block having multiple through holes which are created in parallel and grooves which are created around the opening of the through holes. A conductor is formed inside the grooves and the through holes. The inside conductors and in-groove conductors are connected at the opening of the through hole surrounded with the groove. The inside conductors and an outside conductor are connected at a second end. The opening of the through hole is formed inside an open-circuit end of the dielectric block.

Dielectric filter and RF apparatus employing thereof

A push&mdash;push oscillator is formed by (a) a resonator circuit including a transmission line having one-half wavelength and both ends of the line being left open, and a capacitance for frequency control coupled to the transmission line in parallel, and (b) two oscillators electrically identical to each other and their input sections being coupled to both the ends of the transmission line. Further, this oscillator can take out an output signal of even-order-harmonics from a midpoint of the transmission line in a transmitting direction as well as take out two fundamental waves from respective output sections of two branch oscillators. This push&mdash;push oscillator operating with a high frequency is downsized and simplified from a conventional one. Its phase-noise-characteristics and noise immunity are also improved.

Push-push oscillator

A strip-line filter is provided with upper- and lower-stage resonators having the same electromagnetic characteristics. Each of the resonators has a one-wavelength square-shaped strip line and four open-end transmission lines connected to four coupling points A, C, B and D (or E, G, F and H) of each resonator which are spaced 90 degrees in electric length in that order. The square-shaped strip lines having a pair of parallel coupling lines closely placed in parallel to each other to electromagnetically couple the resonators. Therefore, the filter can be manufactured in a small size. A first microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points A and B (or E and F), and a second microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points C and D (or G and H). Therefore, resonance wavelengths of the microwaves can be longer than a line length of each square-shaped strip line. Also, the resonance wavelengths can be adjusted by trimming the transmission lines. Also, because all constitutional elements are made of strip lines, the filter can be made plane.

Plane type strip line filter in which strip line is shortened and dual

A strip-line filter is provided with upper- and lower-stage resonators having the same electromagnetic characteristics. Each of the resonators has a one-wavelength square-shaped strip line and four open-end transmission lines connected to four coupling points A,C,B and D (or E,G,F and H) of each resonator which are spaced 90 degrees in electric length in that order. The square-shaped strip lines have a pair of parallel coupling lines closely placed in parallel to each other to electromagnetically couple the resonators. Therefore, the filter can be manufactured in a small size. A first microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points A and B (or E and F), and a second microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points C and D (or G and H). Therefore, resonance wavelengths of the microwaves can be longer than a line length of each square-shaped strip line. Also, the resonance wavelengths can be adjusted by trimming the transmission lines. Also, because all constitutional elements are made of strip lines, the filter can be made plane.

Plane type strip-line filter in which strip line is shortened and dual

A strip dual mode filter includes a strip line ring resonator having a uniform line impedance and an electric length equivalent to a wavelength of a microwave, an input terminal coupled to a point A of the ring resonator, a feed-back circuit connected to points C and D and arranged in a central hollow space of the ring resonator and an output terminal coupled to a point B of the ring resonator. The points A to D are spaced by a quarter-wave length of the microwave in that order. The microwave input to the point A is resonated in the ring resonator in a first mode and is input to the feed-back circuit from the point C. Therefore, a phase of the microwave shifts by a multiple of a half-wave length of the microwave, and the microwave is output to the point D. Thereafter, the microwave is resonated in the ring resonator in a second mode orthogonal to the first mode and is output from the point B to the output terminal. Therefore, the microwave can be resonated and filtered in two orthogonal modes in the strip dual mode filter.

Strip dual mode filter in which a resonance width of a microwave is

A strip dual mode filter consists of a strip line ring resonator having an electric length equivalent to a resonance wavelength .lambda..sub.o for resonating microwaves at the resonance wavelength .lambda..sub.o according to a characteristic impedance thereof, an input coupling capacitor for transmitting the microwaves from an input terminal to a coupling point A of the ring resonator, an output coupling capacitor for outputting the microwaves resonated in the ring resonator from a coupling point B of the ring resonator to an output terminal, and a phase-shifting circuit connected to a coupling point C and a coupling point D of the ring resonator for changing the characteristic impedance of the ring resonator by shifting a phase of the microwave by a multiple of a half-wave length of the microwaves. The coupling point B is spaced a quarter-wave length of the microwaves apart from the coupling point A, the coupling point C is spaced the half-wave length of the microwaves apart from the coupling point A, and the coupling point D is spaced the half-wave length of the microwaves apart from the coupling point B.

Dual mode multistage filter

A first oscillator includes: a ring resonator; an oscillation circuit having a negative resistance active circuit coupled to a first point on the ring resonator for oscillating at an oscillation frequency and resonating the resonator; an output terminal, coupled to a second point on the ring resonator where a voltage is substantially zero with respect to the predetermined frequency when the ring resonator resonates, for outputting a resonant frequency signal, wherein even order harmonic components are outputted with the fundamental component suppressed. A second oscillator includes a ring resonator having points A to D equidistantly dividing the ring resonator, first and second oscillation circuits coupled to the points A and B respectively, first and second grounding capacitors having capacitance equivalent to those of the first and second oscillation circuits. Thus, two independent oscillators which do not affect each other are provided with a single resonator. In the first and second oscillators, grounding capacitors, a resonant capacitor may be provided to miniaturize the oscillator. Variable capacitances may be provided to prevent the point from moving with a change in the controlled oscillation frequency. Frequency synthesizers and communication apparatus including the first or second oscillator are also disclosed.

Ring resonator oscillator usable in frequency synthesizers and

A strip dual mode filter consists of a strip line ring resonator having an electric length equivalent to a resonance wavelength .lambda..sub.o for resonating microwaves at the resonance wavelength .lambda..sub.o according to a characteristic impedance thereof, an input coupling capacitor for transmitting the microwaves from an input terminal to a coupling point A of the ring resonator, an output coupling capacitor for outputting the microwaves resonated in the ring resonator from a coupling point B of the ring resonator to an output terminal, and a phase-shifting circuit connected to a coupling point C and a coupling point D of the ring resonator for changing the characteristic impedance of the ring resonator by shifting a phase of the microwave by a multiple of a half wavelength of the microwaves. The coupling point B is spaced a quarter wavelength of the microwaves apart from the coupling point A, the coupling point C is spaced the half wavelength of the microwaves apart from the coupling point A, and the coupling point D is spaced the half wavelength of the microwaves apart from the coupling point B.

Loop-shaded strip line dual mode multistage filter in which the strip

A strip dual mode filter consists of a strip line ring resonator having an electric length equivalent to a resonance wavelength .lambda..sub.o for resonating microwaves at the resonance wavelength .lambda..sub.o according to a characteristic impedance thereof, an input coupling capacitor for transmitting the microwaves from an input terminal to a coupling point A of the ring resonator, an output coupling capacitor for outputting the microwaves resonated in the ring resonator from a coupling point B of the ring resonator to an output terminal, and a phase-shifting circuit connected to a coupling point C and a coupling point D of the ring resonator for changing the characteristic impedance of the ring resonator by shifting a phase of the microwave by a multiple of a half-wavelength of the microwaves. The coupling point B is spaced a quarter-wavelength of the microwaves apart from the coupling point A, the coupling point C is spaced the half-wavelength of the microwaves apart from the coupling point A, and the coupling point D is spaced the half-wavelength of the microwaves apart from the coupling point B.

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Kawasaki, Japan

Hiroyuki Yabuki