Samsung Electro-mechanics Co., Ltd.

Samsung Electronics Co., Ltd.

Kouki Tanji

Eiichiro Otobe

Tsuyoshi Sugiura

Toshihiko Yoshimasu

A voltage-controlled oscillator includes a first transistor, a second transistor, an inductive impedance element, a first variable capacitive impedance element, and a second variable capacitive impedance element. The first transistor has a source coupled to a first power source, a drain coupled to a first node, and a gate coupled to a second node. The second transistor has a source coupled to the first power source, a drain coupled to the second node, and a gate coupled to the first node. The inductive impedance element has a first terminal coupled to the first node and a second terminal coupled to the second node. The first variable capacitive impedance element has a first terminal coupled to the first node and a second terminal coupled to a third node. The second variable capacitive impedance element has a first terminal coupled to the second node and a second terminal coupled to the third node.

Voltage-controlled oscillator

There is provided an amplifying apparatus which can prevent characteristic deterioration while reducing costs. The amplifying apparatus includes a first amplifier connected between an input terminal to which a high-frequency signal is input and an output terminal through which the high-frequency signal is output, including a bipolar transistor, and amplifying the high-frequency signal input from the input terminal; a second amplifier including a bipolar transistor, amplifying the high-frequency signal input from the input terminal, and having a lower maximum output power than that of the first amplifier; and a switching unit connected between the second amplifier and the output terminal, and selectively outputting the high-frequency signal amplified by the second amplifier through the output terminal.

Amplifying apparatus

A switch is capable of performing switching, while reducing distortion with respect to amplitude of a high frequency signal. The switch includes: an input terminal to which a high frequency signal is input; a first switching unit connected between the input terminal and a first output terminal and selectively outputting the high frequency signal through the first output terminal; and a second switching unit connected between the input terminal and a second output terminal and selectively outputting the high frequency signal through the second output terminal. Each switching unit includes an impedance transformer installed on a signal line, a bipolar transistor having an emitter grounded, a collector connected to the signal line, and a base receiving current according to a control voltage applied thereto; and a bipolar transistor having a collector grounded, an emitter connected to the signal line, and a base receiving current according to the control voltage.

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Yokohama, Japan

Kouki Tanji