Abstract: A transmitter circuit includes an output impedance and a buffered oscillator. The buffered oscillator includes a resonator for generating a reference signal and an amplifier coupled with the resonator for amplifying the reference signal. A first resonant tank generates an oscillating output signal in response to the amplified reference signal. A buffer circuit buffers the oscillating output signal and lowers the output impedance.

Abstract: An oscillation circuit of phase-shift type includes a surface acoustic wave filter in a feedback circuit, the surface acoustic wave filter having first and second one-port surface acoustic wave resonators of different resonance frequencies connected in a ladder configuration. The oscillation circuit has a high C/N ratio with a large bandwidth of variable frequency and can be fabricated in a small size with low costs.

Abstract: Disclosed herein is a magnetostatic wave device that employs a single-crystal thin film of the formula Y.sub.3-x M.sub.x Fe.sub.5-y N.sub.Y O.sub.12 (where M denotes at least one member selected from La, Bi, Lu, and Gd, N denotes at least one member selected from Al, In, and Sc, and x and y are defined as 0<x.ltoreq.1.0 and 0<y.ltoreq.1.5, respectively) which is formed by liquid phase epitaxy on a single-crystal substrate of Gd.sub.3 Ga.sub.5 O.sub.12, characterized in that said single-crystal thin film has a lattice constant larger than that of said single-crystal substrate, with the difference (.increment.a) between the two lattice constants being in the range defined by 0.0004 nm.ltoreq..increment.a.ltoreq.0.001 nm. It has good characteristic properties (e.g., low insertion loss and ripple).

Abstract: A transmitter system for transmitting an output signal having an output level and a signal to noise ratio. The transmitter system comprises a balanced oscillator comprised of a resonator for generating a reference signal, and for creating a parasitic impedance. Moreover, the balanced oscillator comprises a first oscillator comprising a first amplifier for amplifying the reference signal, and a first feedback circuit for generating a first oscillating output signal in response to the reference signal amplified by the first amplifier. Similarly, the balanced oscillator comprises a second oscillator comprising a second amplifier for amplifying said reference signal, and a second feedback circuit for generating a second oscillating output signal in response to the reference signal amplified by the second amplifier.

Abstract: A digitally-controlled SAW stabilized FSK oscillator circuit having an oscillator and a single-port SAW resonator with a predetermined circuit resonant frequency and being coupled to the oscillator for establishing a first oscillator output frequency, F.sub.SAW. A bipolar transistor has at least one predetermined shunt capacitance value, C, that is placed in electrical series with the single-port SAW resonator when the transistor is in the OFF state and a closed switch that replaces the capacitance when the transistor is in the ON state to cause the first frequency, F.sub.SAW, to be generated by the oscillator when the transistor is ON and to cause a second frequency, F.sub.2, to be generated by the oscillator when the transistor is in the OFF state.

Abstract: A crystal-controlled oscillator circuit is modified by the present invention by replacing the crystal with the first signal port of a two-port SAW resonator filter that has a low-loss primarily inductive characteristic and taking the oscillation output from the other port of the filter to provide an oscillator frequency with harmonics that are reduced significantly when compared to the output of a crystal-controlled oscillator.

Abstract: A low-power, self-quenching superregenerative receiver utilizes a single-port SAW device coupled to an RF oscillator to establish the frequency of oscillation at the output of the RF oscillator. A diode detector is coupled from the oscillator output for detecting a predetermined amplitude of the oscillation output signal. A time-constant circuit is coupled from the signal detector for generating an oscillator quench signal when the oscillator signal is detected and the oscillator quench signal has a predetermined duration set by the time-constant circuit. A feedback circuit couples the oscillator quench signal to the RF oscillator to cause the RF oscillator to switch to a non-oscillating condition only during the predetermined duration of the RF oscillator quench signal. The RF oscillator then switches to the oscillating condition and the system repeats itself.

Abstract: A high stability clock oscillator circuit that has no inductors in the oscillator circuit itself. In the preferred embodiment neither the collector, the base, nor the emitter of the transistor is grounded and the oscillator output is taken from the collector of the transistor. In an alternate embodiment the collector is AC grounded and the output is taken across a load resistor coupled between the emitter of the transistor and ground. The resulting oscillator is a high stability oscillator that can be used as a dock oscillator in high frequency circuits.

Abstract: An oscillation circuit and an oscillation method for generating a high-frequency signal in which NPN transistors are differentially connected to each other. The signal output from the collector of a first NPN transistor is positively fed back to the base of a second NPN transistor via a first capacitor, and the signal output from the collector of the second NPN transistor is positively fed back to the base of the first NPN transistor via a second capacitor. A one-port-type SAW resonator is connected to the collectors of the NPN transistors via the capacitors for blocking the flow of direct current. Thus, it becomes possible to generate a high-frequency signal with a high degree of accuracy.

Abstract: A balanced and buffered oscillator and transmitter arrangement includes a first and second oscillator, each of which include a resonator for generating a reference signal, an amplifier for amplifying the reference signal, a resonant tank for generating an oscillating output signal in response to the amplified reference signal, and a buffer circuit for buffering the respective oscillating output signal such that the effects of a parasitic impedance are minimized.

Abstract: An oscillator-transmitter (100) includes an input tank circuit (101) coupled between a first amplifier (103) and a second amplifier (105) configured in an oscillator arrangement. An output tank circuit (107, 109, 111 ), for radiating radio-frequency energy, is coupled between outputs (106, 110) of the first and second amplifiers (103, 105). The output tank circuit (107, 109, 111) radiates energy provided by both the first and second amplifiers (103, 105).

Abstract: Multiple resonator stages are connected in series to form a closed loop. Each of these cascaded resonator stages includes at least a high frequency resonator and an amplifier. The amplifier amplifies the output of the high frequency resonator. Each stage also includes a power divider connected to the amplifier output. The power divider has at least two outputs. One of the two power divider outputs serves as an output of the oscillator formed by the cascaded resonator stages. The other output of the power divider is connected to the input of the next high frequency resonator stage. The oscillator further includes a phase shifter connected between two of the high frequency resonator stages to achieve a closed loop phase shift of N(360) degrees at the oscillator operating frequency, where N is an integer. The high frequency resonators may be acoustic resonators such as surface acoustic wave resonators (SAWR).

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 component-module-adapted oscillating circuit arrangement adapted to form a signal with a high frequency and a narrow frequency range includes a signal amplifying circuit, a signal generating circuit with a resonance element, required electrical wiring, and required matching network. On one surface of a carrier substrate belonging to the component module, electrically conductive surface sections are formed and distributed in such a way that they can coact in a firm and electrically conductive manner with corresponding contact surfaces of the resonance element. An integrated circuit is attached to the surface sections adjacent to the surface sections intended for the resonance element. This integrated circuit includes the required amplifying circuit. The contact surfaces of the resonance element are connected to the contact surfaces of the carrier substrate by bonding or the like.

Abstract: An FSK modulator including an amplifier for oscillation has a surface acoustic wave resonator connected in series with a switching circuit formed without a variable-capacity diode but including a semiconductor switch and one or more fixed-capacity capacitors. When an input signal is received, the switch causes a capacitor or combination of capacitors to become connected in series with the surface acoustic wave resonator, providing oscillations with two frequencies to effect FSK modulation.

Abstract: An oscillating circuit includes a resonator for outputting a signal, an amplifier for amplifying the signal output from the resonator, and a radiator for transmitting a radio wave by resonating the signal amplified by the amplifier. The amplifier has a transistor connected to the resonator and a fixed inductor applying an alternating current load to the transistor. The transistor outputs a signal to be adjusted by the fixed inductor to finely adjust the frequency of the radio wave.

Abstract: A balanced oscillator and transmitter circuit is provided which includes a pair of balanced Colpitts-type oscillators for generating an enhanced power radiating output signal. The balanced oscillators share a series resonance input tank. Each oscillator has an amplification stage which preferably includes a Colpitts-type configured transistor. The transmitter circuit further includes first and second output tanks having first and second radiating elements which may include a pair of inductors. An oscillating current signal is generated by the oscillator and is commonly transmitted through the pair of radiating elements. Each radiating element transmits radiating output signals which are combined and summed in total to provide an efficient radiating output signal. Alternately, the first and second output tanks may include a center-tapped transformer coupled to a third radiating element.

Abstract: Low time-bandwidth product linear frequency modulated chirp pulses are repetitively generated as contiguous subpulses to form a pulse of extended duration with each subpulse respectively mixed with one of a plurality of stepped intermediated frequencies so that the bandwidth of the contiguous subpulses is increased to the frequency bandwidth of all of the stepped intermediate frequencies such that the contiguous signal formed has a linearly varying frequency over the increased bandwidth and increased pulse duration, providing a large time-bandwidth product linear frequency modulated chirp waveform particularly useful in radar systems.

Abstract: A SAW oscillator circuit including a housing having disposed therein a surface wave propagation supporting substrate with a pair of transducers coupled by surface waves propagating through the substrate and electronic circuitry connected to the pair of transducers and arranged to provide, with the connected resonator, the SAW oscillator circuit. A weight is attached to the resonator. The housing is susceptible of vibratory deflections which induce vibratory deflections in the substrate and the weight suppresses the vibratory deflections induced in the substrate of the resonator. With such arrangement, while sufficiently thick externally mounted stiffeners are not used because of space limitations, the effects of vibratory deflections induced in the substrate of the insufficiently thick, or un-stiffened housing are compensated by the weight attached to the resonator.

Abstract: A surface acoustic wave resonator has a plural number N of interdigital transducers arranged in a sequence on a piezoelectric substrate to generate N surface acoustic wave signals with a predetermined frequency f.sub.0 and having phase difference of 2.pi./N radian therebetween. Oscillation circuits are individually connected to the N interdigital transducers and generate N oscillation signals with the same frequency f.sub.0 and having phase difference of 2.pi./N radian therebetween. These oscillation signals are multiplied together to generate a signal with frequency N times the predetermined frequency f.sub.0.

Abstract: A voltage controlled surface acoustic wave oscillator includes an integrated circuit and a two port resonator connected as a feedback element around the integrated circuit. The integrated circuit includes a phase shifting network and an amplifier directly connected to the phase shifting network.

Abstract: A tunable oscillator circuit (200) includes surface acoustic wave transducer (303) disposed on a piezoelectric substrate (301) having a high SAW coupling coefficient. The SAW transducer is (303) non-reflective and self-resonant comprising a pair of electrodes with interdigitated fingers. A tuning mechanism, such as a varactor, is coupled across the transducer allowing for output frequency tuning of the oscillator circuit.

Abstract: A gain stage for providing an automatic phase shift is provided. In particular, the gain stage detects whether an oscillation signal appears at its inputs. If an oscillation signal is not detected, then the gain stage inverts output signals occurring at outputs of a first amplifier before being respectively applied to inputs of a second amplifier. This has the overall effect of implementing a 180.degree. phase shift of a signal appearing at the outputs of the gain stage with respect to a signal appearing at the inputs of the gain stage.

Abstract: A semiconductor device having a semiconductor substrate or an insulation layer, an integrated circuit on each of the opposite sides, or main surfaces, of the semiconductor substrate or insulation layer, and a path for an ultrasound signal interconnecting the integrated circuits. The path is afforded by an ultrasonic transducer on each of the opposite sides of the semiconductor substrate or insulation layer. A plurality of paths may be provided in the same semiconductor substrate or insulation layer without crosstalk by transmitting ultrasound signals having different frequencies through the respective paths. The paths may be one-way or two-way. The ultrasonic transducers each contain a piezoelectric material; the thickness of the piezoelectric material in the ultrasonic transducer, at least on the receiver side in each path, is such that the resonant frequency of the ultrasonic transducer corresponds to the frequency of the ultrasound signal signal transmitted through the path.

Abstract: A coupled resonator filter oscillator having an impedance matching network coupled between an amplifier and a filter. The impedance value of the amplifier varies due to amplifier gain compression. The network maintains a constant impedance to the filter when said amplifier's impedance changes to preserve the filter's original transfer function.

Abstract: An SW resonator has a substrate of piezoelectric material. Two reflectors are applied onto the one substrate side. Input and output transducers are situated between the reflectors. The SW resonator is expanded to form an SW resonator having three electrical gates by arranging an additional transducer between the reflectors.

Abstract: An integrated tunable resonator (100) includes a common semiconductor carrier (110). Formed on the common semiconductor carrier (110) is an integrated voltage variable capacitor (104). A bulk acoustic wave resonator is formed on the common semiconductor carrier (110) and coupled to the voltage variable capacitor (104). In one aspect of the present invention, a thin film resonator (106) is coupled to the voltage variable capacitor (104) both of which are formed on a common semiconductor substrate (110). The combination of these three elements provide for a tunable integrated resonator (100). In another aspect of the present invention, a surface acoustic wave resonator (522), formed on a common semiconductor carrier (514), is coupled to a voltage variable capacitor (520) in order to provide a tunable resonator (500).

Abstract: A microwave voltage controlled oscillator (12) and isolation amplifiers (14, 16) are formed as a monolithic circuit on a single GaAs substrate. Only a single external inductor (34) is required to set the oscillation frequency. Optionally, an external resonator (38) may be used instead of an inductor. Off-chip active bias control (LIMin, 18) is provided for convenient frequency tuning.

Abstract: A transceiver has an RF oscillator stage shared by the receiving and transmitting modes. The RF oscillator has a feedback loop incorporating a SAW delay line. A switching arrangement selectively couples the antenna to the transmission circuit and optionally couples the antenna to the receiving circuit. The RF oscillator stage is isolated from switching perturbations by small capacitors at the input and at the output of the oscillator.

Abstract: A delay device comprises a semi-conductor chip having acoustic charge transport channel disposed therein; a contact operably connected to and disposed at one end of the channel for injecting an electronic signal into the channel; a transducer for generating a single frequency, large amplitude acoustic surface wave through the channel for thereby transporting the electronic signal through the channel; a plurality of electrodes operably associated with the channel and disposed along the propagation path of the surface acoustic wave for non-destructively sensing the electronic signal; switches monolithically disposed on the chip and operably connected to the electrodes for preselecting any one of the electrodes, thereby extracting a delayed replica of the signal from the channel; and an output circuit for processing the extracted signal for generating an output.

Abstract: A SAW stabilized oscillator includes a phase locking circuit which is phase locked to a lower frequency reference signal having an odd order difference with respect to the fundamental frequency of the SAW oscillator. A mixer is disposed in the phase locking circuitry and is used as a sub-harmonic phase detector by mixing the fundamental with an odd harmonic of the reference signal.

Abstract: An electrically tuned super-regenerative receiver (10) comprises a feedback type oscillator having a signal output and a signal input, phase shift components (30) connected in a feedback loop for coupling the signal output to the signal input to cause oscillations, and a quench oscillator (35) coupled to the signal input for switching the oscillator between an oscillating and a non-oscillating condition. A variable capacitance device (40), such as a varactor diode, is connected between the signal output and a reference potential (21), and a microprocessor (105) provides a tuning voltage (42) which is applied at the signal output for varying the current in the varactor diode, thereby varying the oscillator center operating frequency. The oscillator center operating frequency is detected by a spectrum analyzer (112) and compared to a desired center operating frequency by a controller (118).

Abstract: A voltage controlled oscillator includes a resonant circuit formed of an impedance in series with a voltage variable capacitance. The impedance consists of a surface acoustic wave resonator in parallel with either an inductance coil or another acoustic wave resonator.

Abstract: A surface acoustic wave device having interdigitated transducers comprised of an improved metalization system including copper and titanium doped aluminum transducers. A method of producing the interdigitated transducers includes deposition of the metals on a quartz substrate and subsequent heat treatment. The metalization system provides SAW devices having improved long-term frequency stability, particularly when operated at high power levels. The surface acoustic wave device may be incorporated in a feedback loop of an amplifier to form an oscillator circuit.

Abstract: An optical oscillator uses a monochromatic light beam passing through a poelectric crystal subjected to acoustic vibrations which cause the emission of a diffracted light beam. The undiffracted beam is detected by photodetecting means and generates a first voltage signal. The diffracted beam is passed through a unit for delaying the passage of the beam, e.g. a fiber optics loop, and detected by photodetecting means to generate a second voltage signal. The signals are combined and fed to a control unit which allows a radio frequency signal to reach the piezoelectric crystal, causing acoustic vibrations. The time delay and voltage output relationships in the loop associated with the diffracted beam cause oscillation and control the frequency of such oscillations. The oscillations can be amplitude and frequency modulated by variation of appropriate circuit parameters.

Abstract: In an oscillator of the invention, the shape and position of each chip and wiring between the chips are optimally designed. Since a SAW element and an IC which have satisfactory reliability are arranged in the same package, the oscillator is not greatly influenced by external electromagnetic induction, is not unstably oscillated, and has satisfactory reliability.

Abstract: A Colpitts oscillator has an integrated circuit. The integrated circuit includes a transistor having an equivalent large size, a bypass capacitor connected between a collector of the transistor and a ground, a first feedback capacitor connected between a base and an emitter of the transistor, a second feedback capacitor connected between the emitter of the transistor and the ground, and an emitter follower connected to the emitter of the transistor. In a package, a stray reactance and a bonding wire are designed so as to agree with an element value and a Q value which can be used as parts of a resonator. A surface elastic wave resonator disposed outside the integrated circuit is connected between the base of the transistor and the ground. The oscillator is voltage controlled by a variable capacitance diode connected in series with the resonator.

Abstract: A modulator includes a plurality of piezoelectric resonators, a plurality of oscillator circuits, arranged in a one-to-one correspondence with the plurality of piezoelectric resonators, for generating different frequency signals in correspondence with corresponding piezoelectric resonators, and a switching circuit for selecting a predetermined frequency signal from the plurality of different frequency signals on the basis of a value of a digital signal to be modulated, and for outputting the selected frequency signal as a modulation signal.

Abstract: An electronically controlled oscillator capable of operating in the rf/microwave frequency range, and using a stacked crystal filter as the frequency determining element in the oscillator. A non-linear element including an appropriately biased high frequency amplifier has the stacked crystal filter connected in its feedback path and provides a loop gain of greater than 1 to meet one aspect of the Barkhausen criteria. An electronically variable impedance, such as a hyperabrupt junction varactor, is connected in the feedback loop along with the stacked crystal filter to controllably insert a phase adjustment into the feedback path, to be compensated by a phase adjustment by the stacked crystal filter, thereby to controllably maintain a loop phase shift which is an integral number of 2.pi. radians at the oscillator frequency, and to vary the oscillator output frequency about the frequency of the stacked crystal filter in a controllable fashion.

Abstract: An improved epitaxial single crystal wafer suitable as a working element of magnetostatic wave devices is proposed which comprises a substrate single crystal wafer of a rare earth gallium garnet, e.g., gadolinium gallium garnet, neodymium gallium garnet and samarium gallium garnet, and an epitaxial layer formed thereon having a chemical composition, different from conventional yttrium iron garnet, Y.sub.3 Fe.sub.5 O.sub.12, of the formula(Y.sub.1-x M.sub.x).sub.a Fe.sub.8-a O.sub.12 or (Y.sub.1-x M.sub.x).sub.a (Fe.sub.1-Y Q.sub.y).sub.8-a O.sub.12,in which M is an element selected from the group consisting of bismuth, lanthanum, gadolinium and lutetium, the subscript a is a positive number in the range from 3.0 to 3.1, the subscript x is a positive number in the range from 0.01 to 0.9, Q is an element selected from the group consisting of aluminum, gallium, indium and scandium and the subscript y is a positive number in the range from 0.1 to 0.2.

Abstract: A first transistor is connected in grounded-collector-emitter-follower configuration to generate a high enough negative resistance to overcome the oscillating resistance of the crystal resonator connected to the base electrode. A second transistor connected in grounded-base configuration serves as a buffer and impedance transformer between the low impedance output of the first transistor and the high impedance of a load. An inductor connected between the resonator and the first transistor input and a variable capacitance approximating the shunt capacitance of the resonator connected across the first transitor input form an impedance inverter which absorbs the resonator shunt capacitance and converts the effect of the resonator to a parallel tuned circuit that can be broadly tuned.

Abstract: In an oscillator of this invention, a differential amplifier circuit is constituted by connecting the collectors of first and second transistors to one terminal of a DC power source respectively through first and second resistors, the emitters of the first and second transistors to the other terminal of the DC power source through a common current-source, and the bases of the first and second transistors to a bias circuit for applying a bias voltage, at least one port of a piezo-electric device having at least two ports on a single substrate is connected between the collectors of the first and second transistors, and the remaining port is connected between the bases of the first and second transistors. The transistors can be field effect transistors, and the common current-source can be a resistor. In this oscillator, since no DC voltage is applied across transducers of each port, degradation of a piezo-electric device can be prevented.

Abstract: An oscillator and a resonator included in the oscillator are operated at a requency that is not the resonator frequency but that is off resonance at a frequency where the resonator has a minimum acceleration sensitivity and the desired oscillator output frequency is then electronically produced using electronic frequency synthesis techniques.

Abstract: A microwave surface acoustic wave resonator stabilized oscillator includes an amplifier having an input terminal and an output terminal and a feedback circuit disposed around said amplifier for providing a closed loop about said amplifier having an integral multiple of 2.pi. radians of phase shift and excess small signal gain at a frequency f.sub.o. The SAW resonator is disposed in the feedback means and is selected to operate in a fundamental mode of operation and provides a resonant circuit having a resonant frequency f.sub.o. The feedback circuit around the amplifier causes the loop to oscillate at a frequency at which the phase shift is an integral multiple of 2.pi. radians and which has excess small signal gain. As the circuit starts to oscillate, the overall gain in the loop is compressed and the loop amplifier is forced to operate in a non-linear region.

Abstract: An oscillator with a surface acoustic wave filter connected in its feedback path. The oscillator includes an attenuator in the feedback path for attenuating to a predetermined level an oscillating signal fed back to the surface acoustic wave filter from an amplifier used to excite the oscillation. The attenuation is sufficient to prevent damage to the acoustic wave filter.

Abstract: This invention relates to a tactile sensor that is particularly suitable for use in robotics. The tactile sensor enables a robot, cybernetic device, or other appropriate automatic mechanism to sense an object, to measure the force of contact, and to determine the force necessary to seize the object. Acoustic surface waves propagated along the surface of an insulating plate within the sensor, and disrupted by contact with the sensor, are used to achieve this purpose.

Abstract: A microwave oscillator circuit having a voltage controlled oscillator for producing a controllable frequency microwave signal and a high overtone bulk acoustic resonator coupled to receive the signal is provided with a light source for directing a light beam onto the resonator such that the light is diffracted in response to the presence of acoustic waves produced in the resonator by the microwave signal. Diffracted and undiffracted portions of the light beam are measured and compared to provide an indication of resonance phenomena within the high overtone bulk acoustic resonator. This technique is particularly applicable to frequency agile stable local oscillators in radar equipment. Optical data extraction is completely non-invasive with respect to the microwave circuit functions, resulting in unimpaired stable local oscillator operation.

Abstract: A voltage controlled oscillator circuit having an amplifier coupled in series with a feedback circuit and having adjustable voltage means coupled to the phase shifting element means for varying the phase shift of the phase shifting element output signal thereby varying the frequency of oscillation of the oscillator circuit.

Abstract: A phase shift oscillator formed with a surface acoustic wave coupled resonator in series with an amplifier and wherein the coupled resonator has a substantially 180.degree. phase shift occurring between the 3dB points of the frequency response curve of the coupled resonator.

Abstract: A superregenerative detector utilizing a single transistor and having a surface acoustic wave device in the feed back loop coupling the output to the input to cause oscillation wherein the surface acoustic wave device is a low loss delay line formed as a single phase unidirectional transducer on a quartz substrate.