Abstract: A circuit includes a first node, a second node, a third node between the first and second nodes, a first field effect transistor coupled between the first and third nodes, a second field effect transistor coupled to the third node including a second gate terminal coupled to a second resistor, a third field effect transistor coupled to the third node including a third gate terminal coupled to a third resistor, a first capacitor coupled to the second field effect transistor, a second capacitor coupled to the third field effect transistor, a third capacitor coupled between the second and third nodes, and a fourth field effect transistor coupled between the second and third nodes.

Abstract: A circuit includes a first node, a second node, a third node between the first and second nodes, a first field effect transistor coupled between the first and third nodes, a second field effect transistor coupled to the third node including a second gate terminal coupled to a second resistor, a third field effect transistor coupled to the third node including a third gate terminal coupled to a third resistor, a first capacitor coupled to the second field effect transistor, a second capacitor coupled to the third field effect transistor, a third capacitor coupled between the second and third nodes, and a fourth field effect transistor coupled between the second and third nodes.

Abstract: A communication device includes a transmission signal processing unit, a driver amplifier coupled to the transmission signal processing unit, a selector coupled to the driver amplifier, a first attenuator coupled to the selector and an output portion of the communication device, a second attenuator coupled to the selector and the output portion of the communication device, and a controller coupled to the selector and the driver amplifier to switch between the first attenuator and the second attenuator based on a notification signal.

Abstract: An attenuator includes a first terminal, a second terminal, a first circuit coupled between the first and second terminals and including a field effect transistor including a gate terminal coupled to a resistor, a second circuit coupled between the first circuit and the second terminal, coupled to the first circuit via a node, and including another field effect transistor including another gate terminal coupled to another resistor, and a third circuit coupled to the node. The resistor and the another resistor are coupled to different nodes respectively.

Abstract: An attenuator includes a first node, a second node, a first circuit coupled between the first and second nodes, a second circuit coupled between the first circuit and the second node, and coupled to the first circuit via a third node, a third circuit coupled to the third node, and a variable capacitor coupled to the third node and configured to regulate an attenuation characteristic of the attenuator such that a flat attenuation characteristic can be achieved within a predetermined frequency range.

Abstract: An attenuator includes a first terminal, a second terminal, a first circuit coupled between the first and second terminals and including a field effect transistor including a gate terminal coupled to a resistor, a second circuit coupled between the first circuit and the second terminal and coupled to the first circuit via a node, and a third circuit coupled to the node.

Abstract: An attenuator includes a first terminal, a second terminal, a first circuit coupled between the first and second terminals and including a field effect transistor including a gate terminal coupled to a resistor, a second circuit coupled between the first circuit and the second terminal, coupled to the first circuit via a node, and including another field effect transistor including another gate terminal coupled to another resistor, and a third circuit coupled to the node. The resistor and the another resistor are coupled to different nodes respectively.

Abstract: A communication device includes a transmission signal processing unit, a driver amplifier coupled to the transmission signal processing unit, a selector coupled to the driver amplifier, a first attenuator coupled to the selector and an output portion of the communication device, a second attenuator coupled to the selector and the output portion of the communication device, and a controller coupled to the selector and the driver amplifier to switch between the first attenuator and the second attenuator based on a notification signal.

Abstract: The attenuation characteristics of an attenuator largely changes depending on the frequency of an input signal. Accordingly, a difference between the amounts of attenuation of gains of each two attenuators included in a communication device is not constant. In communications using the wireless USB, the difference needs to be in a range of 2 dB±1 dB. Thus, the communication device does not meet the standards of the wireless USB unless the difference between the amounts of attenuation of the attenuators is adjusted. In this regard, provided is a communication device including first and second attenuators that attenuate a signal. The second attenuator is provided with a regulator circuit that adjusts a relation between an amount of attenuation of the signal through the first attenuator and an amount of attenuation of the signal through the second attenuator.

Abstract: An attenuator includes a first terminal, a second terminal, a first circuit coupled between the first and second terminals and including a field effect transistor including a gate terminal coupled to a resistor, a second circuit coupled between the first circuit and the second terminal and coupled to the first circuit via a node, and a third circuit coupled to the node.

Abstract: An attenuator includes a T-type two terminal pair network including first and second terminals, first, second and third circuits, wherein the first terminal receives an input signal to be attenuated, wherein the first circuit is connected between the first and second terminals, wherein the second circuit is connected between the first circuit and the second terminal and is connected to the first circuit via a node, wherein the third circuit is connected to the node, and a capacitor connected to the node, wherein the capacitance value of the capacitor is variable.

Abstract: An attenuator includes a T-type two terminal pair network including first and second terminals, first, second and third circuits, wherein the first terminal receives an input signal to be attenuated, wherein the first circuit is connected between the first and second terminals, wherein the second circuit is connected between the first circuit and the second terminal and is connected to the first circuit via a node, wherein the third circuit is connected to the node, and a capacitor connected to the node, wherein the capacitance value of the capacitor is variable.

Abstract: The attenuation characteristics of an attenuator largely changes depending on the frequency of an input signal. Accordingly, a difference between the amounts of attenuation of gains of each two attenuators included in a communication device is not constant. In communications using the wireless USB, the difference needs to be in a range of 2 dB±1 dB. Thus, the communication device does not meet the standards of the wireless USB unless the difference between the amounts of attenuation of the attenuators is adjusted. In this regard, provided is a communication device including first and second attenuators that attenuate a signal. The second attenuator is provided with a regulator circuit that adjusts a relation between an amount of attenuation of the signal through the first attenuator and an amount of attenuation of the signal through the second attenuator.

Abstract: In the existing technique in which the attenuation characteristic of an attenuator is adjusted by a voltage value, there are problems that a scale of a circuit of the attenuator increases because a new circuit for supplying voltage such as a step-down circuit becomes necessary, and that a thermal noise and a shot noise are mixed in an output signal of the attenuator. To solve the above-mentioned problems, provided is an attenuator comprising a T-type two terminal pair network including first and second circuits connected in series, and a third circuit connected in shunt between these first and second circuits. A shunt capacitor is connected between the first and second circuits independent from the third circuit.