Abstract: A single-pole double-throw switch includes switching units which are set between a first port and a second port and between the first port and a third port, respectively, and are configured to perform complementarily. The each switching unit includes an antenna port, a circuit port, a transmission line configured to couple them, and a switching element connected between the transmission line and a ground. The switching element includes a parallel circuit including a transistor and an inductor connected in parallel, and a capacitor connected in series with the parallel circuit. The transmission line has a characteristic impedance different from a impedance seen inside the switching unit from the antenna port and a impedance seen inside the switching unit from the circuit port.

Abstract: A single-pole double-throw switch includes switching units which are set between a first port and a second port and between the first port and a third port, respectively, and are configured to perform complementarily. The each switching unit includes an antenna port, a circuit port, a transmission line configured to couple them, and a switching element connected between the transmission line and a ground. The switching element includes a parallel circuit including a transistor and an inductor connected in parallel, and a capacitor connected in series with the parallel circuit. The transmission line has a characteristic impedance different from a impedance seen inside the switching unit from the antenna port and a impedance seen inside the switching unit from the circuit port.

Abstract: An envelope detecting circuit is for generating an envelope signal of an input RF signal as described. The envelope detecting circuit includes an input terminal, an output terminal, a balun, a transistor, and an integrating circuit. The transistor, which is operated in the class B or the class C mode, receives an input signal from the balun, amplifies the input signal, and outputs an amplified signal. The integrating circuit, which is provided between the transistor and the output terminal, provides a series circuit of a resistor and a capacitor between the bias supply and ground. The transistor receives the bias through the resistor. The capacitor holds bottom levels of the amplified signal.

Abstract: An envelope detecting circuit is for generating an envelope signal of an input RF signal as described. The envelope detecting circuit includes an input terminal, an output terminal, a balun, a transistor, and an integrating circuit. The transistor, which is operated in the class B or the class C mode, receives an input signal from the balun, amplifies the input signal, and outputs an amplified signal. The integrating circuit, which is provided between the transistor and the output terminal, provides a series circuit of a resistor and a capacitor between the bias supply and ground. The transistor receives the bias through the resistor. The capacitor holds bottom levels of the amplified signal.

Abstract: A marchand balun with a reduced plane size is disclosed. The marchand balun provides two coupling units each having two transmission lines coupled to each other and having a length of ?/8, where ? is a characteristic wavelength of a signal subject to the marchand balun. The marchand balun further provides an additional unit, where two coupling unit and the additional unit are connected in series to each other. The additional unit is one of a transmission line with a length of ?/16 with one open end and a capacitor with one grounded end.

Abstract: An envelope detecting circuit is for generating an envelope signal of an input RF signal described. The envelope detecting circuit includes an input terminal, an output terminal, a transistor, and an integrating circuit. The transistor, which is operated in the class B or the class C mode, receives the input RF signal from the input terminal, amplifies the input RF signal, and outputs an amplified signal. The integrating circuit, which is provided between the transistor and the output terminal, provides a series circuit of a resistor and a capacitor between the bias supply and the ground. The transistor receives the bias through the resistor. The capacitor holds bottom levels of the amplified signal.

Abstract: A harmonic mixer that suppresses the degradation of the conversion efficiency is disclosed. That harmonic mixer includes an input transmission line, an output transmission line, and two transistors connected in parallel between the input transmission line and the output transmission line. Two transistors are complementarily driven by a local signal LO and generate an output signal RF with frequencies of 2×fLO±fIF, where fLO and fIF are frequencies of a local signal LO and an intermediate signal IF.

Abstract: A marchand balun with a reduced plane size is disclosed. The marchand balun provides two coupling units each having two transmission lines coupled to each other and having a length of ?/8, where ? is a characteristic wavelength of a signal subject to the marchand balun. The marchand balun further provides an additional unit, where two coupling unit and the additional unit are connected in series to each other. The additional unit is one of a transmission line with a length of ?/16 with one open end and a capacitor with one grounded end.

Abstract: A harmonic mixer that suppresses the degradation of the conversion efficiency is disclosed. That harmonic mixer includes an input transmission line, an output transmission line, and two transistors connected in parallel between the input transmission line and the output transmission line. Two transistors are complementarily driven by a local signal LO and generate an output signal RF with frequencies of 2×fLO±fIF, where fLO and fIF are frequencies of a local signal LO and an intermediate signal IF.

Abstract: An active attenuator is disclosed. The attenuator includes a divider to divide an input signal into two signals, a phase shifter to shift a phase of one of output signals of the divider, and a combiner to combine an output of the phase shifter with another of output signals of the divider. The phase shifter includes a coupler and two reflectors, or two amplifiers to cause a phase difference between two signals.

Abstract: An electronic circuit includes: a first resistor having a first terminal and a second terminal; a first transmission line that is coupled to the first terminal of the first resistor, has a first terminal to which a first input signal is input, and has a second terminal outputting a first output signal having a phase difference with respect to the first input signal; and a second transmission line that is coupled to the second terminal of the first resistor, has a first terminal to which a second input signal having a phase difference with respect to the first input signal is input, and has a second terminal outputting a second output signal having a phase difference with respect to the second input signal and having, the phase difference being smaller than a phase difference between the first input signal and the second input signal with respect to the first output signal.

Abstract: An active attenuator is disclosed. The attenuator includes a divider to divide an input signal into two signals, a phase shifter to shift a phase of one of output signals of the divider, and a combiner to combine an output of the phase shifter with another of output signals of the divider. The phase shifter includes a coupler and two reflectors, or two amplifiers to cause a phase difference between two signals.

Abstract: A circuit includes: a first line to which input and output signal terminals are connected; a first transistor having a first terminal connected to the first line, a second terminal connected to a ground potential, and a control terminal supplied with a first oscillation signal, the first transistor outputting the first signal and its harmonic component; a second transistor having a first terminal connected to the first line, a second terminal connected to the ground potential, and a control terminal supplied with a second oscillation signal, the second transistor outputting the second signal and its harmonic component; a first harmonic generator connected to the control terminal of the first transistor and generates a harmonic component including the harmonic component by the first transistor; and a second harmonic generator connected to the control terminal of the second transistor and generates a harmonic component including the harmonic component by the second transistor.

Abstract: An electronic circuit includes a first transistor having a first terminal grounded, a second transistor having a control terminal coupled with a second terminal of the first transistor, a first terminal grounded via a first capacitor, and a second terminal to which a DC power supply is connected, a first distributed constant line having one end connected to a first node between the second terminal of the first transistor and the control terminal of the second transistor and another end grounded via a second capacitor, a second distributed constant line having one end connected to the second terminal of the first transistor and another end connected to the first node, a third distributed constant line having one end connected to the control terminal of the second transistor and another end connected to the first node, a resistor connected between a second node between the first line and the second capacitor and a third node between the first terminal of the second transistor and the first capacitor, and a path

Abstract: An electronic circuit includes: a first resistor having a first terminal and a second terminal; a first transmission line that is coupled to the first terminal of the first resistor, has a first terminal to which a first input signal is input, and has a second terminal outputting a first output signal having a phase difference with respect to the first input signal; and a second transmission line that is coupled to the second terminal of the first resistor, has a first terminal to which a second input signal having a phase difference with respect to the first input signal is input, and has a second terminal outputting a second output signal having a phase difference with respect to the second input signal and having, the phase difference being smaller than a phase difference between the first input signal and the second input signal with respect to the first output signal.

Abstract: A circuit includes: a first line to which input and output signal terminals are connected; a first transistor having a first terminal connected to the first line, a second terminal connected to a ground potential, and a control terminal supplied with a first oscillation signal, the first transistor outputting the first signal and its harmonic component; a second transistor having a first terminal connected to the first line, a second terminal connected to the ground potential, and a control terminal supplied with a second oscillation signal, the second transistor outputting the second signal and its harmonic component; a first harmonic generator connected to the control terminal of the first transistor and generates a harmonic component including the harmonic component by the first transistor; and a second harmonic generator connected to the control terminal of the second transistor and generates a harmonic component including the harmonic component by the second transistor.

Abstract: An electronic circuit includes a first transistor having a first terminal grounded, a second transistor having a control terminal coupled with a second terminal of the first transistor, a first terminal grounded via a first capacitor, and a second terminal to which a DC power supply is connected, a first distributed constant line having one end connected to a first node between the second terminal of the first transistor and the control terminal of the second transistor and another end grounded via a second capacitor, a second distributed constant line having one end connected to the second terminal of the first transistor and another end connected to the first node, a third distributed constant line having one end connected to the control terminal of the second transistor and another end connected to the first node, a resistor connected between a second node between the first line and the second capacitor and a third node between the first terminal of the second transistor and the first capacitor, and a path

Abstract: An electronic device includes a first transmission line, a second transmission line and a ground-coupling portion. The first transmission line is composed of a first signal line transmitting a given high frequency wave signal and a first ground. The second transmission line is composed of a second signal line transmitting the high frequency wave signal and a second ground. The ground-coupling portion couples the first ground and the second ground. A phase difference between the high frequency wave signals at both ends of the ground-coupling portion is substantially integral multiple of 180 degrees.

Abstract: An electronic device includes a first transmission line, a second transmission line and a ground-coupling portion. The first transmission line is composed of a first signal line transmitting a given high frequency wave signal and a first ground. The second transmission line is composed of a second signal line transmitting the high frequency wave signal and a second ground. The ground-coupling portion couples the first ground and the second ground. A phase difference between the high frequency wave signals at both ends of the ground-coupling portion is substantially integral multiple of 180 degrees.