Abstract: In a high power oscillator for frequencies on the order of microwave and above, a method and apparatus for tuning the oscillator in response to a control voltage applied thereto by utilizing a relatively low power varactor diode in a harmonic cavity coupled to the oscillator and without loss of efficiency.

Abstract: An improved pulsed power supply for a solid state diode oscillator is shown. In the preferred embodiment a voltage equal to the threshold voltage of a negative resistance diode oscillator is applied continuously through an appropriately sized resistor and at least one normally nonconducting transistor is connected in parallel with such resistor, the transistor being arranged to be turned to its conducting state when a driver produces a control pulse, thereby to cause the negative resistance diode oscillator to oscillate.

Abstract: A microwave oscillator in which the power supplied by 2N microwave diodes such as avalanche or Gunn effect diodes is added. The diodes are connected together in two by sections of strip lines which enables magnetic coupling between these diodes and a dielectric resonator, with the diodes in each couple operating in phase opposition.

Abstract: An improved solid state transmitter (and elements therefor) adapted particularly well to pulsed operation at radio frequencies is disclosed. Such transmitter includes the combination of: A crystal-controlled oscillator producing a continuous wave output signal which, ultimately, determines the frequency of each transmitted pulse; a first oscillatory circuit, including a resonant cavity and at least one normally quiescent coaxial oscillator incorporating an IMPATT diode; a second oscillatory circuit, including a resonant cavity and a plurality of normally quiescent coaxial oscillators, each one of such oscillators incorporating an IMPATT diode; and an improved modulator for periodically actuating all of the IMPATT diodes in such a manner that a pulsed output of the first oscillatory circuit is produced which remains locked to the then existing continuous wave signal out of the crystal-controlled oscillator and the pulsed outputs of the coaxial oscillators in the second oscillatory circuit similarly are locked.

Abstract: A power combining device for combining the microwave power from a plurality of solid state devices comprises a housing defining a resonator cavity with a plurality of co-axial microwave circuits, including a microwave diode at one end of each circuit and a tapered adjustable attenuator at the other end thereof, which are positioned annularly about the resonator cavity so that the energy generated therein is combined within the cavity and transmitted by way of a common outlet. The power combiner is provided with a broad range of bandwidth adjustment by providing for the adjustment of many of the parameters of the system including the length of the circuits, the damping of the circuits, and length of the resonator cavity, and the degree of coupling to adjacent circuits.

Abstract: An attenuation equalizer, having a constant resistance is comprised of a distributed constant line having a given impedance and electrical length connected to both the input and output terminals of the equalizer, and an additional constant line having a given impedance and electrical length connected to the input and output terminals through resistors of a given resistance.

Abstract: A fast-switching pulse modulator for generating a high-power output pulse in response to a low-power input pulse to apply a bias signal to a microwave apparatus having a high efficiency avalanche semiconductor diode such as a TRAPATT diode or IMPATT diode formed of GaAs. The modulator uses a transistor operating in a switching mode. The transistor is biased to a non-conducting state preferably by a negative D.C. bias voltage and switched to a first conducting mode upon application of the positive input pulse to the transistor. At this first conducting mode the transistor switches current from zero to a low-current level during which no RF output signal exists. Upon application of a threshold signal to, for example, the TRAPATT diode, the diode is triggered into the TRAPATT mode generating thereby an RF output pulse. As the diode is triggered into the TRAPATT mode the transistor is switched to a second conducting mode at a high current level.

Abstract: A pulse generating circuit is provided by charging from a DC power source through charging resistor to a capacitor; detecting the preset value of the charging condition of the capacitor; discharging the charge of the capacitor through a main thyristor by triggering the main thyristor and generating a pulse output to a load by the discharging current. The pulse generating circuit comprises a shunt circuit for dividing the voltage of the DC power source beside the circuit for charging the capacitor whereby the potential of the shunt point is compared with the charged voltage of the capacitor through a three terminal trigger element and the trigger element is turned on when the charged voltage of the capacitor becomes substantially equal to the voltage of the DC power source to obtain the trigger output of the main thyristor.

Abstract: A stabilization system for IMPATT diode microwave oscillators, comprising: means for electrical and mechanical support of said IMPATT diode, forming the return conductor of the feeding, the thermal dissipator and the terminal of a transmission line; a power supply feeding conductor for said diode comprising a substantially filamentary conducting element, inductively associated for a portion thereof to a ferrite, said ferrite being characterized in having high losses in the frequency spectrum where spurious oscillations might appear, and practically neglectable losses at the operating frequencies of said IMPATT diode.

Abstract: An injection-locked ultra-high frequency solid-state oscillator employs an injection locking method in which an ultra-high frequency output power from a solid-state oscillator is stabilized by injecting an output signal from another stable oscillator. The signal injected into the solid-state oscillator has an optional frequency low enough as compared to that of the output power from the solid-state oscillator and is supplied through a bias supplying circuit or the like. Injection of such low-frequency signal produces sideband waves around the oscillation-wave from the solid-state oscillator while one of such sideband waves is trapped by a high-Q cavity resonator provided in the vicinity of a solid-state oscillating element of the solid state oscillator. The oscillation wave from the solid-state oscillator becomes low noise with the sideband wave trapped, and the frequency of the oscillation wave from the solid-state oscillator is made variable in obedience to the variation of the injection signal frequency.

Abstract: An improved solid state transmitter (and elements therefor) adapted particularly well to pulsed operation at radio frequencies is disclosed. Such transmitter includes the combination of: A crystal-controlled oscillator producing a continuous wave output signal which, ultimately, determines the frequency of each transmitted pulse; a first oscillatory circuit, including a resonant cavity and at least one normally quiescent coaxial oscillator incorporating an IMPATT diode; a second oscillatory circuit, including a resonant cavity and a plurality of normally quiescent coaxial oscillators, each one of such oscillators incorporating an IMPATT diode; and an improved modulator for periodically actuating all of the IMPATT diodes in such a manner that a pulsed output of the first oscillatory circuit is produced which remains locked to the then existing continuous wave signal out of the crystal-controlled oscillator and the pulsed outputs of the coaxial oscillators in the second oscillatory circuit similarly are locked.

Abstract: An oscillator for very high microwave or millimeterwave frequencies employs a pair of negative-resistance semiconductive devices, each mounted in its own resonant cavity. The two cavities are coupled together by an iris in their common wall. An output waveguide is coupled symmetrically to both sides of the common wall to load both cavities equally. An adjustable mode-control element projects into the cavity to the near vicinity of one of the devices to induce the oscillator to start in the desired mode. Additional dielectric or metallic tuners in the cavities provide a wide variation of frequency.

Abstract: An accumulating cavity microwave oscillator having a plurality of coaxial circuit mounted negative resistance diodes coupled to the cavity wherein the plurality of coaxial circuits may be mounted in concentric circles or in other symmetrical or non-symmetrical configurations and one or more coupling mechanism outputs may be utilized. No output is required to be located at the center of either the accumulator or the auxiliary cavity thereby allowing cavity tuners to be mounted there. The coupling coefficient in the coaxial circuits is equal to one plus the coupling coefficient of the output probes in order to present a relatively constant load to the diodes over the operating frequency range, thereby maximizing the usable operating frequency range.

Abstract: A circuit for microwave oscillators or amplifiers, yielding the maximum microwave power from negative resistance diodes feeding into one and the same waveguide section. Diodes are arranged in pairs symmetrically at the level of one and the same right section of the waveguide but outside the waveguide cavity. In the case where two diodes are used, these are screwed into clamps arranged in chambers opening into the cavity. Cylinders effect impedance matching between waveguides and diodes and are supported mechanically by a shaft which supplies the direct voltage for the circuit.

Abstract: A tunable radiation source employing the stimulated Raman-scattering process is disclosed. The source generates several orders of Stokes radiation in an optical-fiber oscillator cavity, which Stokes radiation may be independently tuned by incorporating separate tuning elements for the several Stokes orders. Several different arrangements of fiber and tuning elements are disclosed.

Abstract: A bias circuit for a large pulse-width, broad-bandwidth radio-frequency avalanche device comprising a power supply coupled to the device through a bias line. The bias circuit includes a resistive network shunted across the bias line and ground to dampen spurious submicrowave oscillations.

Abstract: A balanced circuit for IMPATT amplifiers and oscillators, which includes at least one pair of anti-series connected matched avalanche diodes electrically connected to the junction of a balanced and an unbalanced transmission line is disclosed. The diodes which are pumped by a large-signal input, are d-c biased to operate in the avalanche condition. A parametrically generated pair of unwanted idler frequencies are separated so that one component of the parametric-pair flows in the balanced line, and the other component flows in the unbalanced line. A central branch of the unbalanced line portion is resistively loaded to overcome the parametrically induced negative resistance of the diodes operating in the avalanche condition, and to suppress all incipient unwanted parametrically generated frequencies. The resistance loading, which is frequency independent, has little effect on the impedance presented to the diodes at the large-signal frequency.

Abstract: The present invention relates to microwave circuits for operating on microwave radiations. It consists in combining a dielectric resonator and a microwave diode in a hybrid or integrated circuit, in order to provide a circuit which will operate without any external elements other than a direct current supply for the transmitter and a local microwave radiation for the receiver.

Abstract: A housing defining a first cavity forming a transmission line and a negative impedance semiconductor device terminating one end of the transmission line in a negative impedance, the housing further defining a second cavity resonant at a predetermined frequency and a means of electromagnetically coupling between the transmission line and the second cavity to couple energy therebetween, a reactive element formed between said negative impedance semiconductor device and the housing to provide a shunt susceptance to parallel resonate with the susceptance of the semiconductor device at the desired frequency and bias, and load isolator connected to the opposite end of the transmission line for transmitting RF output pulses to the RF load and for applying a DC bias thereto normally at a first level and periodically reduced to a second level for a short duration, said semiconductor device operating as a series resonant circuit with the DC bias at the first level to cause energy to be stored in the resonant cavity and

Abstract: A receiver module including a mode launcher, a band pass filter, a local oscillator and a balanced mixer for use in the frequency range 1 GHz to 1,000 GHz, wherein the components are all connected by an insular waveguide transmission line having a conductive image plane, a dielectric waveguide attached to the image plane by a thin film of plastic, the thin film being low loss in character and having a low permittivity compared with that of the dielectric waveguide, the ratio between the thickness of the thin film and the square root of the cross-sectional area of the dielectric waveguide being in the range from about 0.02 to about 1.0.

Abstract: A locked hybrid junction power combiner comprises in its simplest version a single hybrid junction (0.degree., 180.degree. and 90.degree.) and an appropriate phase shifting element combining three one port oscillators (one master oscillator strongly locking the other oscillators). The combiner can be extended to combine any odd number of oscillators. Combining efficiency approaching 100% and locking figure of merit exceeding that of the master oscillator have been experimentally observed. Isolating the master oscillator from the hybrid by a circulator, the LHJ combiner can generate high microwave powers with spectral purity of the master oscillator; e.g. Impatt diode power capabilities may be combined with Gunn diode spectral purity. The combiner with an ordinary E-H waveguide hybrid junction can be employed to generate ultra-high microwave powers by combining high power tube sources.

Abstract: Stimulated Raman scattering (SRS) at kHz pulse repetition rates is substantially improved with a laser configuration in which the Raman oscillator mirrors within the laser resonator are removed and the laser mirrors are used for both the laser and the Raman (Stokes) resonators. This sharing of the laser resonator by the Raman oscillator has increased the average power and stability of the first and second Stokes wavelengths, has reduced optical wear on the mirrors, and has resulted in a substantially simplified resonator design.

Abstract: A solid state klystron comprising a switching regulator, power source, tuning adapter, and solid state oscillator utilizing supply voltages identical to those of a standard tube-type klystron.

Abstract: An avalanche transistor (three terminal avalanche device) is provided with a p.sup.+ electrode, for example, added to an n.sup.+ - n - n.sup.+ structure. A reverse bias junction is provided by a first voltage source connected between the p.sup.+ electrode and one of the n.sup.+ electrodes. The magnitude of the reverse bias is such as to cause impact ionization. Forward bias voltage is provided by a second source connected between the other n.sup.+ electrode and the p.sup.+ electrode. Input or control signals are applied in series with the second source to add or subtract from the voltage level of the second source, controlling the number of minority carriers injected into the n.sup.+ - n - n.sup.+ structure to cause a change in breakdown voltage and operating point of the device.

Abstract: A pulse generator with a low duty factor includes a capacitor arranged to alternately be charged via a first current path and discharged via a second current path, the second current path has a thyristor element with its anode-cathode circuit connected across the capacitor and is arranged to be activated by a predetermined capacitor voltage and to be deactivated by a second thyristor element. A resistor network has a first resistor means connected between the anodes of the thyristor elements and two second and third resistor means arranged to connect a pole of the capacitor to the anode of the first thyristor element and to the anode of the second thyristor element respectively. The second thyristor element is arranged to be provided with a trigger voltage generated across a cathode load of the first thyristor element.

Abstract: There is disclosed a time-dispersion tuned Raman oscillator which makes use of the frequency-dependent transit time of Stokes radiation through a long optical fiber. Time-dispersion tuning is effected by synchronizing Stokes radiation of the desired frequency with a pump pulse. This synchronization may be accomplished either by adjusting the delay of the feedback pulse relative to a pump pulse or by adjusting the repetition rate of the pulsed pump laser.

Abstract: An improvement in a prior art microwave diode coaxial oscillator circuit comprising an unloaded fundamental frequency cavity for prevention of energy loss in the matching termination at the resonant frequency of the circuit and a second harmonic resonant cavity for controlling second harmonic loading of the diode and for reducing noise in the output signal.

Abstract: A parametrically-stable microwave circuit comprises in cascade a negative resistance diode, a stabilizing network, and a complementary type filter. The complementary type filter presents a substantially constant impedance to the stabilizing network from low frequencies to the operating frequency by selectively coupling the diode microwave signals to a dummy load or to a circuit load. With its termination thus controlled, the stabilizing network may be designed to suppress spurious parametric oscillations by presenting to the negative resistance diode a predetermined impedance over a broad range of frequencies.

Abstract: An operating parameter such as temperature or pressure is digitally quantized into a plurality of constant-duration first pulses of corresponding amplitude. The first pulses are employed, over the duration of the first pulses, to continually charge a capacitor, which in turn is coupled across an oscillatory discharge path including a diac or other threshold-operated, negative resistance electronic element. The diac is triggered on when the voltage across the capacitor exceeds a predetermined value, and is triggered off again when the voltage thereacross during discharge corresponds to a second predetermined diminished value across the capacitor, thereby effecting the capacitor discharge as a series of constant amplitude relatively short duration pulses whose number is proportional to the amplitude of the first pulse. Advantageously, the second pulses are coupled via a pulse transformer to a full-wave rectifier, and are then routed to a suitable processor for further utilization.

Abstract: A microwave oscillator comprises a wave-guide having a closed end with a semiconductor diode having a negative differential resistance for the frequency used placed in the wave-guide spaced from the closed end and electrically connected to two elements protruding inwardly from opposite walls of the wave-guide, with one of the elements being electrically isolated from the wall and having an unsymmetrical, rotatable body. The wave-guide may be conical if desired.

Abstract: A dielectric waveguide oscillator includes a microwave producing diode, a strip resonator, and a dielectric waveguide butted against one end of the strip resonator.

Abstract: A Transverse Electromagnetic Field (TEM) transmission line or lines with a negative impedance semiconductor device at one end and a lossy radio frequency (RF) load impedance at the other end, a TEM resonant transmission line with output power coupled therefrom, and an opening for coupling energy from the TEM transmission line or lines to the TEM resonant transmission line at the desired frequency with the Q of the oscillator being determined by the amount of coupling provided.

Abstract: A temperature compensated cavity oscillator comprising a resonant coaxial cavity of which the outer conductor is constructed of dissimilar materials. The end walls and adjacent portion of the outer conductor of the coaxial cavity are made of a first conductive material having a first temperature coefficient of expansion. Interposed between the first conductive material of the outer conductor, the middle portion of the outer conductor is made from a second conductive material having a second temperature coefficient of expansion. A tuning rod is displaced through the middle portion of the cavity and capacitively coupled to a center coaxial conductor to provide mechanical tuning of the oscillation frequency and for varying the frequency of the cavity with temperature such that the temperature characteristics of the oscillating element are compensated to produce a substantially stable oscillating frequency.

Abstract: A microwave oscillation device of the invention comprises a cut-off waveguide having a cut-off characteristic with respect to a frequency used. At one end of this cut-off waveguide is provided a coaxial line member, at one end of which is provided a microwave absorber and at the other end of which is disposed an oscillation element. Within said cut-off waveguide is disposed a dielectric resonator so as to be electromagnetically coupled to the oscillation element of the coaxial line member in terms of lumped constant and to an output waveguide provided at the other end of the cut-off waveguide in terms of distributed constant.

Abstract: Disclosed is a dielectric image guide integrated circuit including first and second sections of image guide of preselected cross-sectional areas joined by an image guide transition section of variable cross-sectional area and all mounted on the surface of an image or ground plane. The image guide transition section has a cavity therein for receiving microwave/millimeter wave energy from the first section of the image guide, and this energy is coupled into a diode mounted within the cavity where it is either detected or frequency converted by the diode. Advantageously, the diode may be mounted on a metal cover which is positioned atop the cavity in the waveguide transition section, and it receives its operating bias from a bias pin connection extending through an opening in the ground plane and including a wisker contact to the diode.

Abstract: A frequency tunable microwave apparatus including a semiconductor TRAPATT diode generating a microwave signal at its fundamental, second and third harmonic frequencies. Energy is extracted at the second harmonic frequency and a certain impedance loading is provided at the fundamental frequency and third harmonic by a variable impedance hybrid idler circuit. The hybrid idler circuit comprises a distributed transmission line serially connected to a lumped variable capacitor. Variations in the capacitance of the variable capacitor tune the fundamental frequency without substantially varying the impedance loading conditions of the diode allowing energy to be extracted at the second harmonic frequency throughout the tunable frequency range.

Abstract: A varactor tuning apparatus for tuning a strip transmission line radio frequency device, wherein the device having predetermined operating characteristics includes an active element such as an avalanche diode and a resonant conductive strip section. The tuning apparatus comprises a separate varactor circuit having a varactor mounted on a dielectric substrate including a resonant conductive strip. The varactor circuit is RF coupled to the strip transmission line of the device to provide for tuning the device by varying the reactance of the strip transmission line by electrically changing the capacitance of the varactor.

Abstract: A low noise frequency source utilizes a varactor diode to form a parametric crystal oscillator which may be frequency multiplied to the desired microwave frequency, for radar applications.

Abstract: A thermo-ionic diode with a very noise figure, using a special semiconductor structure, is provided. The structure comprises, upon a P.sup.+ doped silicon substrate, a succession of N-doped layers whose thicknesses and impurity ratios are designed to optimize the noise figure, a final P.sup.+ type layer covering the structure. The injecting junction of the diode is located at the transition between the said P.sup.+ layer and the nearest N type layer having a weak doping.

Abstract: An active millimeter wave integrated circuit including a thin non-metallic waveguiding layer mounted on an image plane and having an opening therein which exposes a given area of the image plane. An active solid state device, such as a millimeter wave diode, is mounted on the exposed area of the image plane, and millimeter wave energy is coupled to and from the device into the waveguiding layer by way of both a metallic ribbon (or wire) bonded to the active device and a connecting metallization pattern atop the waveguiding layer. This metallization pattern may assume various geometries corresponding to functional components such as low-pass filters, resonators, stepped or tapered metallized transitions, and the like, and also provides the desired impedance matching and efficient energy coupling between the active device and the waveguiding layer.

Abstract: A microwave semiconductor amplifier or oscillator system in which a semiconductor device has an avalanching region at a junction and a heat sink having a higher thermal conductivity than said avalanching region in close thermal contact with the said junction. The avalanching region has a width substantially less than 10 times the thickness of said avalanching region but a length substantially greater than said width. The heat sink is made substantially wider than that of the avalanching region so that heat generated in the avalanching region during operation of the system and moving into the heat sink will have a substantial component thereof moving parallel to the junction, thereby decreasing the thermal resistance between the heat source and the heat sink and hence permitting an increased power output from the system.

Abstract: A microwave power generator comprises a cavity resonator and at least two oscillators built using transmission lines and negative resistance diodes, magnetically coupled to the resonator. At least one additional oscillator is added and electrically coupled to the resonator at a point where the electric field is at a maximum, increasing the volumetric power delivered by the generator, by 50%.

Abstract: A two-inductor varactor tunable solid-state microwave oscillator comprising a series tunable circuit wherein one inductor is serially connected with a negative resistance active element, an impedance load, and a varactor. The circuit is tuned by changing the reactance of the circuit by varying electrically the capacitance of the varactor. The second inductor is connected in parallel with the varactor to increase the range of reactance change of the series circuit effected by the variation in capacitance of the varactor to provide thereby for a wider frequency tuning range.

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.

Abstract: Novel apparatus is provided which permits the combination of the peak pulse power from a pair of avalanche diode oscillators, each diode driving a respective one of two symmetrically suspended airstrip transmission lines which are coupled to a common output connector.

Abstract: Novel apparatus is provided which permits the additive combination of the peak pulse power from multiple avalanche diodes operating in the IMPATT mode without spurious signal generation and includes the use of radially disposed combinations of avalanche diodes and coaxial transmission line resonators feeding a common signal output coupler.

Abstract: A modulator for monochromatic beam of radiation, such as a laser beam, consists of a semiconductor crystal body. A sufficient potential is applied to the body to produce a moving zone of resistivity and potential gradient varying from the remainder of the body. The zone may result, for example, from the Gunn effect or the piezoelectric effect. The zone also has optical properties differing from the remainder of the body, so that a beam directed at the crystal can be modulated by the moving zone.

Abstract: The invention utilizes a four-port hybrid junction in which a signal to be amplified or a low level stable reference signal is coupled to a first port in which a pair of similar or matched amplifiers or oscillators are coupled to the respective second and third ports of the hybrid, and in which the resulting amplified or coherent stabilized power of the two amplifiers or oscillators is provided at the fourth port of the hybrid junction.

Abstract: This microwave circuit incorporates a transistor structure that provides either a two port amplifier or an injection frequency locked oscillator. This circuit eliminates circulators employed with Gunn and Impatt diode amplifiers and injection frequency locked oscillators. The collector-base junction is reverse biased so that the collector region functions either in the Impatt mode or in the transferred electron mode. An RF input signal is applied across the forward biased emitter-base junction. With a load across the collector-base junction having a conductance equal to the absolute value of the negative conductance generated by the collector region, the circuit functions as an oscillator at a frequency which is injection locked to the frequency of the input signal. With a load of increased conductance to suppress oscillations, i.e. overload the collector region, the circuit functions as an amplifier.

Abstract: A plasma thyristor circuit is provided for generating high power, ultra-short duration electrical signals. A silicon semiconductor body has first, second and third impurity regions therein with a PN junction formed at the transition between the first and second or the second and third impurity regions. The second impurity region has an impurity concentration of less than about 5 .times. 10.sup.14 atoms/cm.sup.3, and a width of greater than about 80 microns. The ratio of the punch-through voltage of the second impurity region to the reverse breakdown voltage of the PN junction is between 0.3 and 0.7. Power sources apply both a reverse bias voltage across the body greater than said punch-through voltage and less than said reverse breakdown voltage, and a current to the body having a density greater than the saturation current density of the second impurity region.