Mitsubishi Denki Kabushiki Kaisha

Tetsu Ohwada

Moriyasu Miyazaki

Naofumi Yoneda

Tsutomu Endo

Hideyuki Oh-Hashi

Koji Yamanaka

Yukio Ikeda

Kazutomi Mori

Kazuhiro Mukai

Tamotsu Nishino

Akio Iida

Toshiyuki Horie

Yutaka Ozaki

Hiroshi Osakada

Hiromasa Nakaguro

Shiroh Kitao

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

It is an object of the present invention to realize a low-pass filter that has an increased number of stages of filter elements and can obtain a large combined capacitance with a simple configuration of a plane circuit, can set an attenuation pole in the vicinity of a pass band and has a steep out-of band attenuation characteristic. In order to attain such an object, three or more top end open stubs, which are set to have a large electric length in a range in which a length of is shorter than &frac14; of a wavelength of a pass frequency, are disposed substantially in parallel so that their respective open ends face an identical direction to thereby form a combined line, and a high impedance line that is shorter than the wavelength of the pass frequency is connected to at least one part among parts between neighboring ends on the opposite side of open ends of the top end open stubs.

Low-pass filter

An antenna device including matching circuits corresponding to reflection coefficients of antenna elements determined by taking into account the couplings between the antenna elements occurring when the antenna elements are excited with corresponding excitation amplitudes and excitation phases at each of operational frequencies.

Antenna device provided with matching circuits adapted for reflection coefficients

A low-pass filter includes metal stub conductors mounted on a signal conductor at midpoints of adjacent high impedance sections of the signal conductor. The metal stub conductors prevent the occurrence of resonance between the high impedance sections, thereby providing a large attenuation value over a wide frequency band above the cutoff frequency of the low-pass filter.

Antenna device

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Tokyo, Japan

Tetsu Ohwada