Abstract: A temperature-compensated crystal oscillator (TCXO) comprises a voltage-controlled crystal oscillator (VCXO) having a crystal unit, a compensating voltage generator for generating a compensating voltage applied to the voltage-controlled crystal oscillator, a low pass filter inserted between the compensating voltage generator and voltage-controlled crystal oscillator, and a switching element connected in parallel with the low pass filter for short-circuiting across the low pass filter. In a manufacturing process of the temperature-compensated crystal oscillator, switching element is brought into a conducting state when an excitation electrode of the crystal unit is irradiated with an ion beam for adjusting the oscillation frequency.

Abstract: A high-frequency oscillator includes: a substrate composed of a dielectric material; a first transmission line of coplanar structure which is arranged on one principal surface of the substrate; an amplifier having an input terminal and an output terminal and which is inserted into the first transmission line such that the input terminal and output terminal connect to the first transmission line; and a second transmission line which is provided on the other principal surface of the substrate, which electromagnetically couples with the first transmission line, and which constitutes a feedback circuit with respect to the amplifier. The first transmission line is typically a coplanar line of finite length, and the second transmission line is typically a microstrip line.

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 multi-element planar array antenna has a ground conductor formed on a first principal surface of the substrate, a first and a second slot line formed in the ground conductor and intersecting each other, a first and a second microstrip line formed on a second principal surface of the substrate, and traversing the first slot line respectively at positions corresponding to both end sides of the first slot line, a third and a fourth microstrip line formed on the second principal surface, and traversing the second slot line respectively at positions corresponding to both end sides of the second slot line, and four antenna elements of microstrip line type formed respectively in intersection regions between both end sides of the first and second microstrip lines and both end sides of the third and fourth microstrip lines, respectively, on the second principal surface.

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 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 so as to provide connection between paired circuit conductor portions formed in the one principal plane.

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 high frequency oscillator for combining outputs of two oscillator to generate an oscillation output. The oscillators has a substrate, a slot line formed on a first main plane of the substrate and having both longitudinal ends, the both longitudinal ends being electrically short-circuited, a first and a second amplifier for oscillation, each disposed on one and the other side of the slot line, and having outputs of the same oscillation frequency, and an unbalanced transmission line for connecting input terminals of the first and second amplifiers to each other and for connecting output terminals of the first and second amplifiers to each other. The unbalanced transmission line traverses the slot line and forms a closed loop including the first and second amplifiers.

Abstract: A multielement planar antenna has a substrate, a plurality of antenna element pairs disposed on a first main surface of said substrate, each of the antenna element pairs including first and second antenna elements each made of a circuit conductor, a metal conductor disposed on a second main surface of the substrate, and a slot line defined in the metal conductor. Each of the antenna element pairs has a microstrip line interconnecting the first and second antenna elements. The slot line crosses the microstrip lines and is electromagnetically coupled to the microstrip lines for feeding the first and second antenna elements. The slot line is fed at its central area by a microstrip line or a coplanar line.

Abstract: A multi-element planar array antenna has a substrate made of a dielectric material or the like; a planar conductor formed on a first principal surface of the substrate; a first and a second slot line formed in the conductor and intersecting each other; a first and a second microstrip line formed on a second principal surface of the substrate, and traversing the first slot line respectively at positions corresponding to both end sides of the first slot line; a third and a fourth microstrip line formed on the second principal surface, and traversing the second slot line respectively at positions corresponding to both end sides of the second slot line; and four slot line antenna elements formed on the first principal surface respectively in intersection regions between both end sides of the first and second microstrip lines and both end sides of the third and fourth microstrip lines.

Abstract: A two-element slot line array antenna comprises a substrate having a first and a second main surface, a conductor disposed on the first main surface, a slot line formed in the conductor, and a pair of slot line antenna elements formed in the conductor. The slot line has one end side electromagnetically coupled to the pair of antenna elements, and the other end side serving as a feed end. The pair of antenna elements is arranged in parallel with an electric field plane or a magnetic field plane formed by the slot line. The pair of antenna elements and the slot line are arranged in mirror symmetry with respect to a magnetic field plane or electric field plane which starts at the feed end, so that the pair of antenna elements is excited in phase.

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 temperature-compensated crystal oscillator (TCXO) comprises a voltage-controlled crystal oscillator (VCXO) having a crystal unit, a compensating voltage generator for generating a compensating voltage applied to the voltage-controlled crystal oscillator, a low pass filter inserted between the compensating voltage generator and voltage-controlled crystal oscillator, and a switching element connected in parallel with the low pass filter for short-circuiting across the low pass filter. In a manufacturing process of the temperature-compensated crystal oscillator, switching element is brought into a conducting state when an excitation electrode of the crystal unit is irradiated with an ion beam for adjusting the oscillation frequency.

Abstract: A multi-element planar array antenna has a ground conductor formed on a first principal surface of the substrate, a first and a second slot line formed in the ground conductor and intersecting each other, a first and a second microstrip line formed on a second principal surface of the substrate, and traversing the first slot line respectively at positions corresponding to both end sides of the first slot line, a third and a fourth microstrip line formed on the second principal surface, and traversing the second slot line respectively at positions corresponding to both end sides of the second slot line, and four antenna elements of microstrip line type formed respectively in intersection regions between both end sides of the first and second microstrip lines and both end sides of the third and fourth microstrip lines, respectively, on the second principal surface.

Abstract: A high frequency oscillator has a substrate made of, for example, a dielectric material, a resonator circuit disposed on one principal surface of the substrate and formed of a finite-length coplanar line having a signal line and a ground conductor arranged along the signal line on both sides thereof, a negative resistance element for connecting between the signal line and the ground conductor, and an output line routed on the other principal surface of the substrate and electromagnetically coupled to the resonator circuit through the substrate. A Gunn diode is preferably used for the negative resistance element, and is connected, for example, in a substantially central region of the signal line. The output line preferably forms a microstrip line structure together with the ground conductor.

Abstract: A high frequency oscillator has a substrate, a resonator circuit which is disposed on one principal surface of the substrate and consists of a closed loop-shaped slot line including an inner conductor and an outer conductor, an electric boundary point set on the slot line, a two-port negative resistance element for connecting between the inner conductor and outer conductor, and an output line electrically connected to the slot line. The electric boundary point is set by connecting, for example, a stub to the resonator circuit. The stub functions as an electrically short-circuited end or an electrically open end. A Gunn diode is preferably used for the negative resistance element, and inserted at a position of the slot line resonator circuit at which impedance matching is achieved.

Abstract: A high-frequency oscillator includes: a substrate composed of a dielectric material; a first transmission line of coplanar structure which is arranged on one principal surface of the substrate; an amplifier having an input terminal and an output terminal and which is inserted into the first transmission line such that the input terminal and output terminal connect to the first transmission line; and a second transmission line which is provided on the other principal surface of the substrate, which electromagnetically couples with the first transmission line, and which constitutes a feedback circuit with respect to the amplifier. The first transmission line is typically a coplanar line of finite length, and the second transmission line is typically a microstrip line.

Abstract: A high-frequency filter for use in a superhigh frequency band such as of microwaves and millimeter waves has a substrate, a metal conductor disposed on a first main surface of the substrate, a resonator comprising a transmission line of a coplanar structure which is made of the metal conductor, and input and output lines disposed on a second main surface of the substrate transversely across the resonator and electromagnetically coupled to the resonator. The resonator may be a coplanar line resonator (coplanar waveguide resonator) or a slot line resonator. The high-frequency filter has a steep attenuating gradient in filter characteristics. The high-frequency filter may be combined with variable-reactance devices such as variable-capacitance diodes for electronically controlling the filter characteristics.

Abstract: A high frequency oscillator for combining outputs of two oscillator to generate an oscillation output. The oscillators has a substrate, a slot line formed on a first main plane of the substrate and having both longitudinal ends, the both longitudinal ends being electrically short-circuited, a first and a second amplifier for oscillation, each disposed on one and the other side of the slot line, and having outputs of the same oscillation frequency, and an unbalanced transmission line for connecting input terminals of the first and second amplifiers to each other and for connecting output terminals of the first and second amplifiers to each other. The unbalanced transmission line traverses the slot line and forms a closed loop including the first and second amplifiers.

Abstract: A high frequency oscillator suitable for implementing a push-push oscillator, a push-pull oscillator, and a four-phase push-push oscillator comprises a transmission line resonator, two active devices for oscillation connected to two resonant wave points, respectively, located on the transmission line resonator in an opposite phase relationship to each other, and a combiner line connected to an electric symmetric point of the transmission line resonator. The respective active devices constitute two oscillation systems, respectively, which share the transmission line resonator as a high frequency resonator. The combiner line combines outputs from the respective oscillation systems to generate a high frequency output.