Murata Manufacturing Co., Ltd.

Ikuo Tamaru

Hiroyuki Sasaki

Hirokazu Yazaki

Hiroshi Masuda

Akira Kato

Kiyoshi Aikawa

Makoto Fujita

Akiyoshi Kinoshita

A directional coupler splits an input signal received by an input terminal into four signals to be output to output terminals. The directional coupler includes couplers and phase shifters. The coupler is connected to the input terminal and splits the input signal into two signals to be output to terminals. The coupler splits a signal from the terminal into two signals to be output to the output terminals. The coupler splits a signal from the terminal into two signals to be output to the output terminals. The phase shifter is connected between the terminal and the coupler and advances the phase of the signal from the terminal. The phase shifter is connected between the terminal and the coupler and delays the phase of the signal from the terminal. The phase difference between output signals of the phase shifters is 180°±10°.

Directional coupler

To provide a directional coupler in which a coupling characteristic is made even flatter. There are included an input terminal, an output terminal, a coupling terminal, a termination terminal, ground terminals, a main line, a first sub line, and a second sub line. The main line is electromagnetically coupled to sub lines (first sub line, second sub line). A phase conversion unit (low pass filter) is connected between the first sub line and the second sub line. Between a point between the coupling terminal and the termination terminal, and the ground terminals, a resonant circuit is connected in which an inductor, a capacitor, and a resistor are connected in series.

A directional coupler that achieves flattening of a coupling characteristic and size reduction or miniaturization is used in a predetermined frequency band and includes a first terminal, a second terminal, a third terminal, a fourth terminal, a main line, and a sub line. The main line is connected between the first terminal and the second terminal. The sub line is connected between the third terminal and the fourth terminal. In the sub line, a low-pass filter is provided.

An electronic component includes a capacitor having a desired capacitance value and a laminate including a plurality of laminated insulating material layers. Land electrodes are provided on a bottom surface of the laminate. Internal conductors face the land electrodes, respectively, across the insulating material layer within the laminate, have areas larger than those of the land electrodes, respectively, and contain the land electrodes, respectively, when seen in a planar view from a z-axis direction. A capacitor conductor is provided on the positive direction side of the capacitor conductors in the z-axis direction and faces the capacitor conductors.

Electronic component

A directional coupler used in a predetermined frequency band includes a main line connected between a first terminal and a second terminal. A first sub line is connected to a third terminal and is electromagnetically coupled to the main line. A second sub line is connected to a fourth terminal and is electromagnetically coupled to the main line. A low pass filter is connected between the first sub line and the second sub line and causes a phase shift to be generated in a passing signal passing therethrough in such a manner that the phase shift monotonically increases within a range from about 0 to about 180 degrees with increasing frequency in the predetermined frequency band.

A directional coupler includes in a laminate block, a first main line, a first sub-line, a second sub-line, and a second main line sequentially provided in a lamination direction of layers. Further, each of the first main line, the first sub-line, the second sub-line, and the second main line is divided into at least two divided coil conductors. Furthermore, at least two divided ground conductors are provided between the first sub-line and the second sub-line.

A multilayer bandpass filter includes a first capacitor electrode of a first stage LC parallel resonator, a second capacitor electrode of a second stage LC parallel resonator, and a third capacitor electrode of a third stage LC parallel resonator. Via electrodes and a line electrode define an inductor electrode of the first stage LC parallel resonator. Via electrodes and a line electrode define an inductor electrode of the second stage LC parallel resonator. Via electrodes and a line electrode define an inductor electrode of the third stage LC parallel resonator. The inductor electrodes of the three LC parallel resonators are arranged so loop planes thereof are disposed about a center axis extending in a stacking direction of dielectric layers. This permits setting of electromagnetic coupling between the LC parallel resonators of an input and an output stage, and allows a filter's attenuation characteristics to be freely set.

Multilayer bandpass filter

In a directional coupler, a first low pass filter includes a first coil that is connected between a first outer electrode and a main line and has a characteristic in which attenuation increases with increasing frequency in a certain frequency band. A second low pass filter includes a second coil that is connected between a second outer electrode and the main line and has a characteristic in which attenuation increases with increasing frequency in the certain frequency band. A high pass filter is connected, in parallel to the main line, between a point between the first coil and the first outer electrode and a point between the second coil and the second outer electrode and has a characteristic in which attenuation decreases with increasing frequency in the certain frequency band.

In a directional coupler, sub-lines or main lines are electromagnetically coupled to each other to degrade isolation characteristics. A capacitor is located between the sub-lines or between the main lines to cause the isolation characteristics to have poles in order to improve the isolation characteristics of the directional coupler.

A directional coupler that has a degree of coupling that is close to constant and is to be used in a predetermined frequency band includes a main line between a first outer electrode and a second outer electrode. A sub-line is provided between a third outer electrode and a fourth outer electrode and is electromagnetically coupled with the main line. A low pass filter is provided between the third outer electrode and the sub-line and has a characteristic in which attenuation increases with increasing frequency in a predetermined frequency band.

A balanced-to-unbalanced transformer includes a +90&#xb0; phase shift circuit, which is disposed between a branch point connected to an unbalanced terminal and a first terminal, and a &#x2212;90&#xb0; phase shift circuit, which is disposed between the branch point and a second terminal. A first inductor is connected between the first terminal and a power supply terminal, and a second inductor is connected between the branch point and the power supply terminal. A power-supply-terminal-side capacitor is connected in shunt between the power supply terminal and a ground. A second-terminal-side series inductor is connected in series between the branch point and the second terminal.

Balanced-to-unbalanced transformer and amplifier circuit module

An oscillator includes an oscillating active element having a first main electrical-current path, a buffer-amplifying active element that is of the same type as the oscillating active element, the buffer-amplifying active element having a second main electrical-current path, and a load impedance for the buffer-amplifying active element. The first main electrical-current path, the second main electrical-current path, and the load impedance are connected in series between a power-supply terminal and ground in that order, and the node of the buffer-amplifying active element and the load impedance is a signal outputting point.

Ocillator and electronic device using same

A piezoelectric oscillator includes a piezoelectric element, and an oscillation circuit connected to one of two terminals of the piezoelectric element. One terminal of first capacitance element of which the other terminal is grounded is connected to at least one of the two terminals of the piezoelectric element. A series circuit including a resistor, which has adjustable resistance, can be adjusted and a second capacitance element is connected in parallel to the first capacitance element.

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Nagaokakyo, Japan

Ikuo Tamaru