Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Panasonic Electric Works Co., Ltd.

Atsushi Suwa

Tadayoshi Nakatsuka

Katsushi Tara

Yoshiki Hayasaki

Takaaki Yoshihara

Tomoaki Matsushima

Takeo Shirai

Kenichi Hidaka

Masakazu Adachi

Motoo Nakagawa

Norihiro Yamauchi

Koji Sasabe

Futoshi Nishimura

Sibei Xiong

Tadashi Komatsu

A bandpass filter includes a combination of a BAW filter and a patterned planar filter with stubs. The BAW filter is composed of a plurality of piezoelectric resonators to give a specific frequency bandpass, while the planer filter is configured to attenuate frequencies near and outside the bandpass. The resonators are connected in a ladder configuration between a first signal transmission path and a ground. The planar filter includes a strip line formed on a dielectric layer to define a second signal transmission path. The BAW filter and the planar filter are formed on a common substrate with the first and second transmission paths connected to each other. The BAW filter, in combination with the patterned planar filter added with the stub, can improve a deep near-band rejection inherent to the BAW filter, exhibiting an excellent out-of-band rejection over certain adjacent frequency ranges outside of the bandpass, and therefore give a sharp and wide bandpass.

Bandpass filter and process of fabricating the same

A common terminalis connected to drains of FETsandvia a capacitorFETstoare serially connected, and inserted between a source of the FETand a terminalvia a capacitorSimilarly, each of: FETstoFETstoFETstoFETstoand FETstois inserted between the source of the FETor an FETand a corresponding one of terminalstoThis configuration allows a stray capacitance value of a transmission/reception path to be reduced at the time of transmission/reception, thereby obtaining a favorable radio-frequency characteristic.

Radio-frequency switching circuit and semiconductor device

Four switching circuit sections consisting of four FETs connected in series are provided between a plurality of input/output terminals which output and input a high frequency signal. Gate control voltages are individually applied to gate terminals of four FETs, respectively, so that an on-state and an off-state are achieved. Further drain control voltages are individually applied to drain terminals or source terminals of the FET in each switching circuit section, and a voltage according to an electric power value of the high frequency signal supplied to each of switching circuit sections is supplied as the gate control voltage and the drain control voltage.

High frequency switching circuit and semiconductor device

A field effect transistor switch circuit may include: () first, second, and third switch terminals; () a first field effect transistor, a pair of the main electrodes of which are connected respectively to the first switch terminal and the second switch terminal; and () a second field effect transistor, a pair of the main electrodes of which are connected respectively to the first switch terminal and the third switch terminal. A first resistor is connected between a control electrode and any one of the pair of the main electrodes of the first field effect transistor, and a second resistor is connected between a control electrode and any one of the pair of the main electrodes of the second field effect transistor.

Field effect transistor switch circuit

An object is to provide an antenna switch semiconductor integrated circuit which reduces a consumption current. To this end, of two control input signals which are fed to a logic circuit which controls turning on and off of a plurality of switching FETs, a control input signal for switching between a sending mode and a receiving mode is fed to an oscillation circuit, thereby making the oscillation circuit operate only during the sending mode under which the logic circuit needs a high voltage. A voltage raising circuit accordingly operates, whereby a raised voltage is supplied to the logic circuit. During the receiving mode, the oscillation circuit stops, and the voltage raising circuit stops. With a switch turned on using the logic circuit, a power source voltage is supplied directly to the logic circuit when the voltage raising circuit is not in operation. This shortens the operation time of the voltage raising circuit and reduces the consumption current.

High-frequency switch circuit and mobile telecommunications terminal device using the same

Growing community of inventors

Takatsuki, Japan

Atsushi Suwa