Abstract:
A miniature microstrip/cavity oscillator which is mechanically tunable over a wide range of microwave frequencies and maintains high frequency stability over changes in temperature. The oscillator consists of a RF (resonant frequency) determining element, a microstrip circuit board means, and a capacitive coupling probe coupling the microstrip circuit board means to the RF determining element. The RF determining element is constructed of various materials with different coefficients of linear expansion to eliminate expansion and contraction effects due to temperature changes.
Abstract:
A voltage-variable capacity diode is coupled through a one-third wavelength transmission line to a resonant cavity. The capacity of the diode is varied by a modulating voltage so as to change the resonant frequency of the cavity, and hence the resonant frequency of an oscillator. The transmission line causes the resonant frequency of the cavity to vary more linearly over a relatively wide band as a function of the modulating voltage.
Abstract:
A tuner circuit includes a first IF signal generating a first oscillation signal, a local oscillator circuit outputting a local oscillator signal, a mixing circuit mixing the first IF signal and the oscillation signal to generate a second IF signal, and a first substrate on which at least the local oscillator signal is formed. The local oscillator circuit includes an oscillation circuit and a coaxial resonator connected to the oscillation circuit for correcting the influence of change in oscillation frequency owing to moisture and secular change. The coaxial resonator includes an impedance variable trimmer portion for adjusting the oscillation frequency, a central conductor provided at a fixed position with respect to the first substrate, and an insulator for providing insulation between the impedance variable trimmer and the central conductor. The impedance variable trimmer portion and the central conductor are adhered to one another via the insulator after adjusting is completed.
Abstract:
A microstripline resonator in which a desirable resonant frequency can be adjusted with less deterioration in Q and less production process steps is characterized in that a hollowed-out portion is formed in an electrode portion provided on an insulating substrate base. A width-narrowed portion is provided between the side edge of the electrode portion and the hollowed-out portion for adjusting the resonant frequency of the microstripline resonator.
Abstract:
In a voltage controlled oscillator, a dielectric resonator is mounted on a circuit board and a metal case is mounted on the circuit board to shield the dielectric resonator. The dielectric resonator comprises a C-shaped first electrode which is provided in a dielectric body, second and third electrodes which are arranged on upper and lower sides of the first electrode, a signal connecting pattern which is extended from the first electrode toward a side surface of the dielectric body, and earth connecting patterns which are extended from the first, second and third electrodes toward the side surface of the dielectric body, to provide predetermined impedance between the earth connecting pattern and the signal connecting pattern. The dielectric resonator is arranged with the second and third electrodes in parallel with a major surface of the circuit board, and the second electrode is upwardly exposed. A portion of the second electrode portion at a predetermined position is adapted to be trimmed so as to regulate the resonance frequency of the dielectric resonator, so as to regulate the oscillator frequency of the voltage controlled oscillator. The dielectric resonator can be miniaturized with no reduction of its Q-value.
Abstract:
The present invention relates to a microwave oscillator to be applied to radiosonde. The microwave oscillator in accordance with the present invention is constructed on a plane base plate of dielectric material (insulation material) on whose both sides conductor sheets are provided. The resonance circuit, which is the most important part of the microwave oscillator, is mounted fixedly on the one side of the base plate and electrically connected to the conductor sheet provided on the other side of the base plate. The element for determining the resonance frequency of this resonance circuit assumes a three dimensional form, whereby two bent conductor plates are combined into a case shaped body, whose one side is constructionally and electrically connected to the conductor sheet provided on the one side of the base plate.The transistor, which is an active element of the resonance circuit, is constructionally and electrically connected to a part of the case shaped metal body.The circuit elements for forming the oscillator circuit, such as resistors, the condensers and the transistor and so on are mounted on the other side of the base plate.
Abstract:
Disclosed is a millimeter wave waveguide structure adapted for operation with negative resistance devices, such as solid state avalanche breakdown diodes, at frequencies up to about 170 GHz or higher. A central portion of the structure is formed by a cylindrical metallic impedance transformer and bias pin which has a major face thereof substantially parallel to a common lower waveguide wall of the structure. A negative resistance device is DC coupled between this common waveguide wall and one edge of the impedance transformer, so that the impedance transformer also provides the required DC bias to the negative resistance device. Other portions of the waveguide structure include a first upper waveguide wall, immediately adjacent one side of the impedance transformer, and this wall, together with the common lower waveguide wall, forms a tuning cavity into which a sliding tuning short is positioned. Another portion of the waveguide structure includes a second, upper waveguide wall immediately adjacent the opposite side of the impedance transformer, and this wall together with the common lower waveguide wall, confines millimeter wave power from the negative resistance device to a predetermined path and direction. Suitable waveguide transition means are coupled to the second upper waveguide wall for coupling the above structure to a full height waveguide.
Abstract:
An oscillator (100) includes a resonator (218) having a mirco-strip (217). The micro-strip (217) couples an inductive component (221) to a capacitive portion (219). To tune the oscillator (100), a number of cuts are made on the pad (221) in order to restrict the signal flow. The width of these cuts determine the degree of restriction posed on the signal flow. This controllable restriction of the signal flow provides the circuit (100) with enhanced tunability.