Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Hideyuki Oh-Hashi

Moriyasu Miyazaki

Yukihiro Tahara

Tetsu Ohwada

Yutaka Ozaki

Koji Yamanaka

Satoshi Yamaguchi

Yukio Ikeda

Naofumi Yoneda

Kazutomi Mori

Hidenori Yukawa

Akio Iida

Hideki Asao

Toshiyuki Horie

Hiroshi Osakada

Tetsuya Ohba

Masatoshi Nii

Tetsu Owada

It is an object to obtain a transmission line converter in which a rectangular waveguide provided under a transmission line may be reduced in size. In the transmission line converter including: a rectangular waveguide (); a slot () provided in a wall surface of the rectangular waveguide (); and a transmission line () which extends in a direction of a tube axis of the rectangular waveguide () and includes signal conductors (and) and a ground conductor (), the slot () is provided in a narrower wall surface of the rectangular waveguide () and has a shape in which a central portion of the slot () includes an oblique portion to the tube axis of the rectangular waveguide () and at least one of both end portions of the oblique portion includes a portion parallel to the tube axis of the rectangular waveguide (), and the wall surface of the rectangular waveguide () in which the slot () is provided is a part of the ground conductor ().

Transmission line converter using oblique coupling slots disposed in the narrow wall of a rectangular waveguide

A bandstop filter where variation in characteristics is suppressed to minimum and which realizes an increased production yield. The physical length of a line joint portion between a main line and an oscillator can be enlarged by providing an impedance non-continuous structure portion in a strip conductor of the oscillator. In comparison to the case where the impedance non-continuous structure portion is not provided, the width of a joint slit required to obtain an equal joint amount can be enlarged. When the joint slit width is enlarged, variation in filter characteristics caused by pattern accuracy can be reduced because of the enlarged joint slip width, thus improving a filter yield. This means that pattern accuracy requirement for production is loosened. Freedom in selecting a dielectric substrate is increased, which also provides an advantage that a filter can be produced using a less expensive dielectric substrate with not very high pattern accuracy.

Bandstop filter having a main line and &#xbc; wavelength resonators in proximity thereto

The present invention includes: a first main waveguide; a T-branch circuitconnected thereto; a first low-pass filterconnected thereto; a band-pass filterconnected to the first T-branch circuit; a first converterconnected to the first low-pass filterfor converting transmission lines between a waveguide and a microwave integrated circuit; an amplifierconnected to the first converter and structured by the microwave integrated circuit; a second converterconnected thereto for converting transmission lines between a waveguide and the microwave integrated circuit; a second low-pass filterconnected thereto; a second T-branch circuitconnected to the second low-pass filter and the band-pass filter; and a second main waveguideconnected to the second T-branch circuit.

High frequency module and antenna device

The prior art has a problem in which an isolation between output terminals is deteriorated when a thin film resistor is used as an isolation resistor. Such being the case, in a power divider/combiner comprising an input terminal, two output terminals, two branch lines each connecting the input terminal and one of the output terminals and having a line length that is &frac14; of a set wavelength or a multiple of integer of half a wavelength and &frac14; of the set wavelength, and an isolation resistor connected to between the output terminals, there is provided an improved power divider/combiner further comprising a transmission line interposed between each of the output terminals and the branch lines. Consequently, even when using the isolation resistor having a length that can not be ignored as compared with a wavelength of a high-frequency signal in use, the isolation between the output terminals can be ensured.

Power divider/combiner

An RF circuit module comprising a first RF semiconductor device mounted within a cavity surrounded by a wall of a first dielectric circuit board and a second RF semiconductor device mounted to a second dielectric circuit board placed on the wall A metal base is disposed on the first circuit board and a number of embedded conductors such as via holes are embedded within the wall and arranged to surround the cavity so that each having one end electrically connected to the metal base and the other end exposed and arranged to surround the cavity A metal cover is sealingly attached to the first circuit board to cover the second circuit board and the second RF semiconductor device and electrically connected at the upper surface of the wall Therefore, the first and second RF semiconductor devices are electrically shielded and hermetically sealed, providing an RF circuit module of small-sized and high-performance. The metal cover may have a plate-like shape, the first circuit board may be a high-temperature burned circuit board and the second circuit board may be a low-temperature burned circuit board, the electrical connection between the first circuit board and the second circuit board may be made through a solder bump or an anisotropic conductive sheet. The metal base may be exposed to the cavity, the first circuit board may have mounted thereon a transmission circuit and the second circuit board may have mounted thereon a reception circuit, and a high-frequency circuit device, which is not necessary to be hermetically sealed, may be mounted on the first circuit board outside of the metal cover.

RF circuit module

A frequency synthesizer, which controls the fluctuation of frequency not only of a long period but also a short period, ensures a wide frequency control range and can be realized at a low cost, can be obtained. The frequency synthesizer includes a first control circuit and a second control circuit, the first control circuit having a first variable frequency divider connected between a coupler for extracting a part of an oscillator and a main coil disposed within a magnetic circuit, a first phase detector, a first reference signal generator, a first loop filter and a first coil driving circuit and the second control circuit having a second variable frequency divider connected between said coupler and a sub-coil disposed in said magnetic circuit, a second phase detector, a second reference signal generator, a second loop filter and a second coil driving circuit in order to share the roles in such a manner that the first control circuit controls the fluctuation of the long period frequency, while the second control circuit controls the fluctuation of the short period frequency.

Stabilized frequency synthesizer

Growing community of inventors

Tokyo, Japan

Hideyuki Oh-Hashi