Abstract: An injection-locked high-frequency oscillator has an annular transmission line, and m (m>1) units of oscillating amplifiers, and is provided with an oscillation closed loop formed with the transmission line and the oscillating amplifiers, the oscillating frequency thereof being determined by an electric length of line of the oscillation closed loop. When n≧1 is defined, and when the wavelength corresponding to the oscillating frequency is defined as &lgr;, the electric line length from any one oscillating amplifier to the neighboring oscillating amplifier is set to be n&lgr; by taking delay time due to the oscillating amplifiers into consideration, and further into in-phase points on the oscillation closed loop, synchronizing signals having, respectively, a frequency that is 1/mn of the oscillating frequency are injected.

Abstract: A multielement oscillator employing a higher mode planar resonator being provided with the planar resonator and a plurality of oscillating elements. The planar resonator has a substrate, a resonation circuit conductor provided on a first principal plane of the substrate, a grounded circuit conductor provided on a second principal plane of the substrate, and being provided with a high-order resonance mode due to an electric field generating between paired plurality of positive and negative potential points and a magnetic field associated with the electric field. The oscillating elements are being connected, in at least one principal plane of the first and second principal planes of the substrate, to a plurality of identical potential points of the planar resonator as to provide connection between paired circuit conductor portions formed in the one principal plane.

Abstract: A temperature-compensated crystal oscillator is provided with an IC (integrated circuit) having a power supply terminal, an output terminal, and an automatic frequency control (AFC) voltage input terminal. In the temperature-compensated crystal oscillator, at least one oscillation circuit is integrated and the frequency-temperature characteristic of a quartz crystal unit is compensated. The temperature-compensated crystal oscillator includes one or more damping resistors for reducing the resonance acuteness of parasitic resonance circuits which result from inductance produced when mounting the IC on a wiring board and stray capacitance existing in the vicinity of each terminal of the IC. The dumping resistors are connected to at least one of the power supply terminal, output terminal, and automatic frequency control voltage input terminal.

Abstract: A planar circuit has a substrate, a planar circuit conductor disposed on a first main surface of the substrate, a ground conductor disposed on a second main surface of the substrate for creating a high frequency resonator based on an electromagnetic wave field in cooperation with the planar circuit conductor, and a circuit element disposed on an opening formed in at least one of the planar circuit conductor and ground conductor to electronically control the electromagnetic wave field. The circuit element may be a variable reactance element such as a varactor diode, or a switching element. The circuit element can variably control the electromagnetic wave field which defines the resonator, so that the resonator can be controlled, for example, to resonate at a variable frequency.

Abstract: A quartz-crystal oscillator comprises an oscillating stage and a buffering stage. The oscillating stage has a resonance circuit including a quartz-crystal unit and a capacitor, and an inverting amplifier amplifying a resonance frequency component of the resonance circuit due to feedback oscillation. The buffering stage is provided for outputting the output of the oscillating stage by reducing the amplitude thereof, and has first and second MOS FETs of the same conductive type arranged in series between a power supply and a reference potential. A signal at the output terminal of the inverting amplifier is impressed to the gate of the first MOS FET, a signal at the input terminal of the inverting amplifier is impressed to the gate of the second MOS FET, and an output signal is obtained from a connecting point of the first and second MOS FETS.

Abstract: A crystal oscillator has a quartz-crystal unit, a first oscillating capacitor connected between a first end of the crystal unit and a reference potential point, a second oscillating capacitor connected between a second end of the crystal unit and the reference potential point, a CMOS inverter connected parallel to the crystal unit, and a feedback resistor connected across the inverter. The crystal oscillator can easily be incorporated into integrated circuits and has an increased variable oscillation frequency range. The crystal oscillator also has an adjustable capacitive assembly having selectable capacitances which is connected parallel to a combined capacitor comprising the first and the second oscillating capacitors.

Abstract: A temperature-compensated crystal oscillator with good phase noise characteristics has a crystal unit, a voltage-variable capacitive element inserted in a closed oscillating loop including the crystal unit, and an amplifier for keeping oscillation in the closed oscillating loop. The frequency vs. temperature characteristics of the temperature-compensated crystal oscillator can be compensated for by the temperature compensating voltage input thereto. The temperature compensating voltage is applied to an anode of the voltage-variable capacitive element, and a voltage to prevent a current from flowing through the voltage-variable capacitive element is applied to a cathode of the voltage-variable capacitive element. The voltage-variable capacitive element preferably comprises a variable-capacitance diode.

Abstract: A voltage-controlled oscillator (VCO) using a transistor, capable of-using a capacitor for DC blocking with small capacitance and achieving a large amount of change in the oscillating frequency. The voltage-controlled oscillator comprises a transistor for oscillation and amplification, first and second nodes, a quartz-crystal element inserted between the first and second nodes, a first capacitor connecting the first node with a base of the transistor, a second capacitor connecting the second node with a collector of the transistor, a first variable capacitance diode connected to the first node, a second variable capacitance diode connected to the second node, and means for applying a control voltage to the first and second variable capacitance diodes.

Abstract: A voltage-controlled oscillator (VCO) using a transistor, capable of using a capacitor for DC blocking with small capacitance and achieving a large amount of change in the oscillating frequency. The voltage-controlled oscillator comprises a transistor for oscillation and amplification, first and second nodes, a quartz-crystal element inserted between the first and second nodes, a first capacitor connecting the first node with a base of the transistor, a second capacitor connecting the second node with a collector of the transistor, a first variable capacitance diode connected to the first node, a second variable capacitance diode connected to the second node, and means for applying a control voltage to the first and second variable capacitance diodes.