Abstract: An output terminal 6 is provided at the connecting point 5 between the collector terminal of a transistor 1 and an open-ended stub 4 by connecting the open-ended stub 4 to the collector terminal of the transistor 1, the open-ended stub 4 having a line length equal to a quarter of the wavelength of a signal of frequency 2N·F0 or 2N times the oscillation frequency F0. In addition, an output terminal 9 is provided at a connecting point 8 located at a distance equal to a quarter of the wavelength of a signal of oscillation frequency F0 from the end of an open-ended stub 7 by connecting the open-ended stub 7 to the base terminal of the transistor 1, the open-ended stub 7 having a line length longer than a quarter of the wavelength of the signal of oscillation frequency F0.

Abstract: A switch circuit includes: a first input and output terminal; a first inductor connected with the first input and output terminal; a capacitor connected with the first inductor; a second input and output terminal connected with the capacitor; a first MEMS switch connected with one end of the capacitor; a second MEMS switch connected with the other end of the capacitor; and a second inductor connected between the first MEMS switch and the second MEMS switch, and satisfies a relationship of f=1/(2??CL1)=1/(2??CL2), where L1 is an inductance of the first inductor, L2 is an inductance of the second inductor, C is a capacitance of the capacitor, and f is a use frequency.

Abstract: A voltage-controlled oscillator has a tuned circuit for controlling the oscillation frequency. The tuned circuit has a variable-capacitance element whose capacitance varies in response to a control voltage and a negative capacitance circuit whose impedance frequency characteristics have opposite characteristics to those of a normal capacitance, and which is connected to the variable-capacitance element. The configuration enables increasing the variation ratio corresponding to the control voltage of the combined capacitance composed of the variable-capacitance element and negative capacitance circuit, thereby broadening the oscillation frequency band.

Abstract: An output terminal 6 is provided at the connecting point 5 between the collector terminal of a transistor 1 and an open-ended stub 4 by connecting the open-ended stub 4 to the collector terminal of the transistor 1, the open-ended stub 4 having a line length equal to a quarter of the wavelength of a signal of frequency 2N·F0 or 2N times the oscillation frequency F0. In addition, an output terminal 9 is provided at a connecting point 8 located at a distance equal to a quarter of the wavelength of a signal of oscillation frequency F0 from the end of an open-ended stub 7 by connecting the open-ended stub 7 to the base terminal of the transistor 1, the open-ended stub 7 having a line length longer than a quarter of the wavelength of the signal of oscillation frequency F0.

Abstract: A switch circuit includes: a first input and output terminal; a first inductor connected with the first input and output terminal; a capacitor connected with the first inductor; a second input and output terminal connected with the capacitor; a first MEMS switch connected with one end of the capacitor; a second MEMS switch connected with the other end of the capacitor; and a second inductor connected between the first MEMS switch and the second MEMS switch, and satisfies a relationship of f=1/(2??CL1)=1/(2??CL2), where L1 is an inductance of the first inductor, L2 is an inductance of the second inductor, C is a capacitance of the capacitor, and f is a use frequency.

Abstract: A voltage-controlled oscillator has a tuned circuit for controlling the oscillation frequency. The tuned circuit has a variable-capacitance element whose capacitance varies in response to a control voltage and a negative capacitance circuit whose impedance frequency characteristics have opposite characteristics to those of a normal capacitance, and which is connected to the variable-capacitance element. The configuration enables increasing the variation ratio corresponding to the control voltage of the combined capacitance composed of the variable-capacitance element and negative capacitance circuit, thereby broadening the oscillation frequency band.

Abstract: A resistor 8 for dividing a voltage applied to an anti-parallel diode pair 5 for mixing a DC pulsed signal and a local oscillation signal LO is disposed in pulse modulation circuitry. Therefore, the ratio of the output power of an RF pulsed signal outputted to an RF pulse output terminal 7 at the time of the ON state and the output power at the time of the OFF state can be increased.