Abstract: An inexpensive voltage control type oscillator suitable for use with a mobile radio communication system within a predetermined frequency band range. The oscillator includes a resonance circuit and an oscillation stage formed on a printed wiring board and operating such that the oscillation frequency of the oscillation stage is varied within a predetermined frequency band range by varying the resonance frequency of a parallel resonance circuit included in the oscillation stage on the basis of a control voltage. The parallel circuit comprises a strip line connected in series with a bias resistor and a chip capacitor connected parallel to the strip line. The strip line has an inductance sufficiently larger than that of the resistor and the chip capacitor has a capacitance value so determined that the capacitor resonates at a predetermined frequency in cooperation with the strip line.

Abstract: The present invention teaches an oscillator and transmitter. The balanced oscillator comprises a resonator for generating a reference signal having a resonating frequency, a first oscillator for providing a first oscillating output in response to the resonating frequency, and a second oscillator for providing a second oscillating output in response to the resonating frequency. The second oscillating output has a magnitude equal to the first oscillating output while oscillating 180 degrees out of phase with the first oscillating output. The transmitter comprises an antenna for radiating the first and second oscillating output signals.

Abstract: A phase comparator (91) makes a phase comparison between a frequency-divided signal from a frequency divider (98) and a reference oscillation signal from a reference signal oscillator (90). The phase error signal obtained from the comparison is passed through an LPF (92) to yield a frequency control signal, which is applied to a VCO (94). An oscillated signal from is frequency-multiplied by a frequency multiplier (96). The multiplied output oscillation signal SO is frequency-divided by the frequency divider (98) and output to the phase comparator (91). The multiplied output oscillation signal SO is sent out to a receiver circuit (43) and a transmitter circuit (45).

Abstract: A local oscillator system carries out a frequency switching method, in which local signals with fewer spurious components can be obtained. The local oscillator system is provided with frequency generators for generating signals with different frequencies and frequency dividers connected to the frequency generators. The dividers divide the frequency of the signals to output the frequency-divided signals while operating in an active mode and output undivided signals while the dividers are operating in inactive mode. The dividers are controlled so that one of the dividers is in the active mode and the remaining dividers are in the inactive mode. The output signals from the dividers are combined with each other to form a single output signal and then the single output signal is sent to a filter. The filter selects a component having a desired local frequency from the single output signal. Spurious components caused by unselected frequencies are removed by the filter because they are not divided.

Abstract: An oscillator circuit provides a symmetrical signal without halving the frequency of a crystal oscillator 12. The input 14 of the crystal oscillator 12 is low pass filtered, and the output 18 of the filter 16 is differential voltage compared with the input 14 of the crystal oscillator 12. The output 22 of the differential voltage comparator 20 is symmetrical and of the same frequency as the crystal oscillator 12. The crystal oscillator 12 is preferably a Pierce oscillator.

Abstract: A signal generating device according to the present invention is a device for generating a signal. The device includes a crystal oscillating element and an inverter connected in parallel with the crystal oscillating element. The device is arranged to adjust the amplitude of a signal produced at an input side of the inverter and to capacity-couple the signal produced at the input side of the inverter to an amplifier circuit so that the signal produced at the input side of the inverter is amplified. Accordingly, it is possible to realize a simple construction which includes a reduced number of terminals, which is suited to high-density mounting or is suitably formed as an integrated circuit, and which can be easily reduced in cost.

Abstract: A piezoelectric oscillator in which radiation of higher harmonic components is reduced. A piezoelectric vibrator and a semiconductor device are provided in an oscillation circuit for making the piezoelectric vibrator oscillate, as is a filter for cutting components in a predetermined frequency band or higher harmonic components of an oscillation signal outputted from the semiconductor device. The piezoelectric vibrator, the semiconductor device and the filter are packed in one package. Radiation of the higher harmonic components is reduced by placing the filter close to the oscillator, by providing a shielding or by operating portions of the oscillator output circuit with a reduced supply voltage.

Abstract: A circuit is provided for an oscillator circuit comprising a differential amplifier such as an ECL line receiver which directly, in one step outputs a symmetrical square wave signal. This is obtained by means of a symmetrical connection of the bias voltage to the input terminals of the ECL-line receiver through two substantially equally large resistors. A feedback loop comprises, as is conventional, a crystal and a trimming capacitor or a capacitor which may be controlled in some other way as well as a resistor. The capacitor will together with the resistor form a low-pass filter for the control of the oscillating condition of the circuit. Further, an overtone synthesizer is provided adapted to generate even multiples of the frequency of an input signal and it comprises a second ECL line receiver, the positive and negative output terminals of which are directly connected to each other.

Abstract: An extremely high frequency parasitic signal suppression circuit for use in a local oscillator of an extremely high frequency radio or satellite communication system to eliminate parasitic signals included in a local oscillation signal. A first direct current cut-off device consisting of a microstrip line is connected between the output terminal of a phase-locked oscillator and the input of an amplifier, and to a first low pass filter to supply a direct current source for the amplifier. A second direct current cut-off device and second low pass filter are connected to the output terminal of the amplifier in the same manner as the input terminal.

Abstract: YIG oscillator apparatus comprises both an FET-based YIG oscillator circuit and a bipolar transistor-based YIG oscillator circuit inside a single magnetic structure. Both YIG spheres are disposed in the single air gap of the magnetic structure, which is defined by a pole piece which is tapered to an elongated pole surface which is only slightly larger than necessary to cover both YIG spheres. A band reject filter is included inside the housing for rejecting second harmonics of desired oscillation frequencies only.

Abstract: This invention relates to a high-frequency oscillator constituted by a signal generator for generating a high-frequency signal and a signal output circuit for outputting the generated high-frequency signal. The signal output circuit comprises a capacitor having one terminal to which the high-frequency signal output from the signal generator is applied, and a microstrip line having one terminal, which is connected to the other terminal of the capacitor, and the other terminal set at a reference potential. This signal output circuit can be miniaturized compared with those constituted only by microstrip lines such as conventional signal output circuits. By properly setting the capacitance of the capacitor and the size of the microstrip line, a filter function can also be imparted to the circuit.

Abstract: A monolithic microwave IC oscillator includes a feedback amplifier having a field effect transistor and a varactor diode. The varactor diode has a junction capacitance that varies according to the bias voltage applied to said diode and capacitively couples the amplifier to an external load. Any variation of the capacitance of the load-coupling capacitor caused by design errors or by variations in the manufacturing process can be easily corrected when the device is used. As a consequence, the oscillator can always be operated with good oscillaitng characteristics without hindering integration of individual components and without increasing costs.

Abstract: The microwave oscillation circuit provides a transistor having the collector electrode grounded, the base electrode connected to a resonator circuit determining the oscillation frequency, and the emitter electrode connected to an output open stub. An output transmission line is placed parallel to the output open stub for the output power supplied from the output open stub to be output via an end of the output transmission line to a buffer amplifier. A resistor having an impedance equal to a characteristic impedance of the output transmission line connects a stub circuit to an open end of the output transmission line. The stub circuit exhibits an infinite impedance at the oscillation frequency. At the oscillation frequency, the resistor floats due to the infinite impedance of the stub circuit so that all the oscillation power supplied from the output open stub is output to the buffer amplifier, without being consumed by the resistor.

Abstract: An oscillator operational in the millimeter wave and microwave range, including frequencies greater than 60 GHz, is provided with reduced phase noise by enhancing Q of the resonant circuitry by reactively terminating fundamental frequency oscillation and increasing stored fundamental frequency energy in the resonant circuitry. A two frequency system is provided with constructive reflection of energy at fundamental frequency back to the resonant circuitry, and with isolation of fundamental frequency energy from the output load. Energy to the output load is obtained from the in-situ generated second harmonic of the active element. Phase noise is reduced by enhancing Q by more than an order of magnitude.

Abstract: A varactor tuned oscillator (10), VCO, operational in the millimeter wave range including frequencies greater than 30 GHz, includes a lumped element active circuit (12) with a negative resistance, a lumped element tuning circuit (16) coupled to the active circuit and providing resonant circuitry in combination therewith, and a VCO output (26) reactively terminated at the fundamental frequency of oscillation and generating a higher order output harmonic at least as high as the second order. The reactive termination at fundamental frequency eliminates the intrinsic diminishing effect on tuning range of resistive loading, to extend tuning range and provide an ultrabroadband VCO. The VCO output (26) is resistively loaded at the higher order harmonic. The output is obtained from the higher order harmonic generated in-situ in the active element (14). Measured performance included continuous tuning from 46 to 66 GHz, a 20 GHz tuning range, with a maximum power output of +6 dBm.

Abstract: A harmonic frequency selecting circuit is provided that simply and effectively provides a desired harmonic frequency output signal and that eliminates the need for frequency multiplier circuits. The harmonic frequency selecting circuit includes an oscillator circuit for generating a fundamental frequency signal and a plurality of harmonic frequency signals of the fundamental frequency signal. A phase modulator circuit is coupled to the oscillator circuit for selectively variably attenuating the generated fundamental and harmonic frequency signals. A bandpass filter circuit is coupled to the phase modulator circuit for selecting a predetermined harmonic frequency output signal.

Abstract: A tuned oscillator is disclosed which consists of an active element for oscillation, a ferrimagnetic resonant element connected to part of feedback of the active element, and a matching circuit connected to the active element. The matching cirucit is designed to reflect the fundamental wave produced by the ferrimagnetic resonant element and active and pass the second harmonic wave. Consequently, the magnetic circuit has its load reduced in applying a D.C. magnetic field necessary for frequency tuning to the ferrimagnetic resonance element.

Abstract: A low noise crystal controlled oscillator utilizes a single low impedance modular amplifier in conjunction with matching low impedance fixed element subcircuits to achieve predictable and repeatable frequency stability. A low component count enhances circuit reliability.

Abstract: A magnetically tuned resonant circuit having improved noise performance includes a ferrimagnetic or gyromagnetic body such as a YIG sphere which is disposed within r.f. structure, The r.f. structure is disposed between a pair of pole pieces of a biasing magnet and flux return path. Several techniques are described for reducing fluctuations in magnetic fields through the gyromagnetic body. The gyromagnetic body is isolated from conductive surfaces, or the bulk of conductive surfaces in the region adjacent to the magnetic body are reduced. Further, a technique is also described which provides a break in the electrical continuity around the r.f. structure. Each of these technique reduce the magnitude of thermally induced eddy current flow in conductive regions adjacent to the resonant body. It is believed that such eddy current flow produce random magnetic field variations which produce random variations in the frequency characteristics of conventional magnetically tuned resonant circuits.

Abstract: Phase locked, pulsed oscillator apparatus, for example, for radar use, comprises a pulsed r.f. oscillator, a pulse repetition frequency (PRF) generator and a pulse shaping network. The PRF generator pulsed output signal of frequency, f.sub.1, is reshaped by the pulse shaping network to provide to the input gate of the r.f. oscillator a train of triggering pulses each having a very fast rise time, t.sub.r, which caues the triggering pulses to exhibit significant harmonic power near the r.f. oscillator's free running frequency, f.sub.FR. The reshaped pulses provided by the pulse shaping network gate the r.f. oscillator on and off and cause coherency of the pulsed oscillator output signal relative to the PRF generator output signal. The reshaped pulse rise time, t.sub.r, is preferably less than about 3-4, and more preferably is about two, times the oscillator output signal period, l/f.sub.FR. The peak turn on voltage, V.sub.p, of the reshaped pulses is preferably about twice the average voltage, V.sub.

Abstract: A prescaler input circuit for a frequency converter unit uses a strip line type of directional coupler to isolate the prescaler unit from the frequency converter unit, eliminate beat interference and erroneous frequency dividing operation, and provide a simple and economical structure. The coupler has the prescaler input line inductively coupled to a local oscillator injection element and grounded through a resistor. An earth line is arranged in proximity to the injection lead to provide impedance matching for the coupler.

Abstract: The present invention provides apparatus and a method for determining and correcting frequency offset for use in a frequency synthesizer to provide external control and DC frequency modulation of the synthesizer output frequency. The technique provides DCFM capability by unlocking a phase-lock loop (PLL) which provides the synthesizer reference frequency and making the PLL oscillator (VCO) tune line available for external inputs. Utilizing a frequency counting circuit, the exact output frequency of the VCO is determined. The desired VCO frequency is compared with the actual VCO frequency to derive an error signal proportional to any offset in the VCO frequency resulting from unlocking the PLL. The error signal is then utilized to compensate (the synthesizer output signal) for any frequency change as a result of unlocking the PLL.

Abstract: Odd harmonic generator includes two amplitude limiting amplifiers and a frequency selective signal combining network. Sinusoidal signal at frequency of chrominance subcarrier is applied to inputs of both amplifiers. The first amplifier provides signal comprising fundamental and odd harmonic frequency components. The second amplifier provides signal comprising a fundamental frequency component and odd harmonic frequency components that are comparatively much smaller than the odd harmonic frequency components of the first amplifier's output signal. Signals are combined so that fundamental frequency components offset. Output signal at third harmonic of chrominance subcarrier frequency is used as clock signal for CCD comb filter in a color TV receiver.

Abstract: An electronically tunable solid-state microwave frequency source comprises a transmission-absorption filter incorporated within a magnetic structure. The transmission-absorption filter is employed with a tunable solid-state oscillator and tunable solid-state multiplier to provide a continuously tunable microwave signal source with enhanced spurious signal attenuation over a multiple-octave tuning range. The filter structure comprises a sphere of monocrystalline garnet such as yttrium iron garnet (YIG) and two coupling loops disposed in the field region of an adjustable field DC magnet. The coupling loops are disposed orthogonal to the magnetic field and to each other. In a specific embodiment the first coupling loop is operative to receive at its input the fundamental frequency signal and at its output is grounded, and the second coupling loop is operative to receive a harmonic input signal at its input and to convey a desired output signal at its output.

Abstract: A high frequency generator including a frequency generator and a multiplier, the multiplier including a diode, which multiplies the output frequency of the frequency generator, and shuts off or reduces an output by suspending or suppressing the multiplying operation through the control of a bias voltage applied to the diode used in the multiplier. The system for cutting off the output by controlling the multiplier is very effective for simplifying the circuit structure and reliably turning off the output.

Abstract: A local oscillator circuit includes an inner conductor to which a pick up coil is inductively coupled. The pickup coil is further connected with a capacitor to form a resonance circuit. The resonance frequency of the resonance circuit is set higher than those frequencies in the frequency band of the local oscillator so as to pick up oscillation signals into steady level over the frequency band.

Abstract: A time-delay-triggered TRAPATT oscillator comprising a length of delay line with a TRAPATT diode at one end and a matching filter at the other end, and a constant resistance directional filter at the output end of the matching filter.

Abstract: A broadband high frequency signal generator is disclosed having a low and a high frequency swept signal source connected to a YIG tuned frequency multiplier. One end of an output coupling loop for the YIG is connected to ground through a PIN diode, and the low frequency signal source is connected to the junction of the output coupling loop and the PIN diode. When the PIN diode is caused to conduct, signals from the high frequency source are passed through the YIG tuned multiplier to an output in the conventional manner. When the PIN diode is not conducting, signals from the low frequency source are passed to the output through the output coupling loop.

Abstract: An oscillator is disclosed having a one-stage amplifier and a quartz crystal resonator which operates in series resonance with a L-C oscillating circuit. An oscillating circuit which is tuned to a harmonic of the oscillator frequency is also provided which is connected via a filter device to an output of the amplifier stage. A switching device is provided which short circuits the oscillating circuit tuned to a harmonic as and when required.

Abstract: A linear sensitivity voltage controlled crystal oscillator of the type including a resonator coupled to a negative resistance generator. The resonator comprises a crystal connected in series with a voltage variable capacitance device. The response of the resonator is linearized by the addition of an inductance across the voltage variable capacitance device. A resistor is shunted across the crystal to prevent oscillation at spurious resonances of the resonator.

Abstract: A microwave signal generator having improved noise spectral characteristics employs a plurality of amplifier-frequency multiplier circuits in combination with a very stable VHF oscillator. Instead of lumping the amplification and frequency multiplication together, each in a single stage, a plurality of amplifiers and multipliers are interleaved, as described herein, resulting in reduced FM noise generation.

Abstract: A radar system using a resonant circuit pulsed generator such as a magnetron with a nonresonant filter using directional couplers to split the power output of the generator into two signal channels and to directionally recombine the channels after the channels have passed through different delay times, with the differential delay between the channels being selected to direct the desired frequency components of the generator to a first output port and undesired sidebands or other spurious signals of the generator to a second port.