Abstract: An oscillation module includes a loop interconnection, a high-frequency output interconnection, a differential amplifier, and an output terminal, the differential amplifier is connected to the output terminal with the high-frequency output interconnection, the high-frequency output interconnection crosses the loop interconnection in a grade-separated manner, and the loop interconnection is different in thickness between a crossing part and a non-crossing part with the high-frequency interconnection.

Abstract: A tunable filter device that changes a central frequency and a bandwidth is provided. The tunable filter device may include a body forming a cavity together with a cover, a resonator attached to or integrally formed on a lower surface of the cavity, a frequency-tuning element including a head and a shaft, the shaft passed through the cover and inserted in the resonator, and a cam disposed on the head to contact the head, wherein an insertion length of the shaft is controlled by the cam.

Abstract: A parallel resonance frequency can be adjusted in order to stably and securely block different high frequency noises flowing into a line such as a power feed line or a signal line from electric members including a high frequency electrode within a processing chamber. A filter 102(1) coaxially accommodates a coil 104(1) within a cylindrical outer conductor 110, and a ring member 122 is coaxially installed between the coil 104(1) and the outer conductor 110. The ring-shaped member 122 may be a plate body of a circular ring shape on a plane orthogonal to an axial direction of the outer conductor 110 and made of a conductor such as cupper or aluminum and electrically connected with the outer conductor 110 while electrically insulated from the coil 104(1).

Abstract: An adaptor for a solid-state oscillator and related microwave adaptors includes an input segment of a conductive material, a first coaxial portion that includes a first inner conductor coupled to the input segment and a first outer shielding segment, and a capping portion coupled to the first coaxial portion to electrically couple the first inner conductor and the first outer shielding segment.

Abstract: A coaxial resonator device includes a substrate including a chip-and-wire circuit. A resonator is coupled to the substrate using a conductive epoxy. A system includes a resonator device. The resonator device includes a housing having one or more connectors, a resonator coupled to the housing a conductive epoxy, and a chip-and-wire circuit connecting the resonator to the one or more connectors.

Abstract: Doppler-inspired methods for signal generation and frequency up-conversion are provided that are compatible with CMOS technology. In accordance with an embodiment, a circuit is provided that includes two input signals that can propagate on artificial transmission lines in opposite directions, resembling the relative movement of source and observer in Doppler frequency shift; and an output signal combiner. By controlling the characteristics of the transmission lines and the input signal frequencies, the harmonic generation of active devices is utilized and combined to provide the desired high-frequency component at the output.

Abstract: The present invention is, in one aspect, a radio frequency source, comprising a gyromagnetic precession oscillator. In a second aspect, the gyromagnetic precession oscillator comprises a closed, non-magnetic, cylindrical outer conductor defining a cavity therein; an axial field solenoid wound about the outer conductor; a non-magnetic, cylindrical inner conductor disposed within the cavity and coaxially aligned with the outer conductor; a plurality of cylindrical ferrite precessors, each defining a respective bore through which the inner conductor runs; a plurality of dividers disposed within and defining a resonant chamber in the cavity; and a dielectric material filling the cavity. In a third aspect, the radio frequency source is actively tunable. In a fourth aspect, the radio frequency source that is tunable pulse-to-pulse.

Abstract: A synthesizer module/oscillator assembly includes a voltage controlled oscillator with a coaxial resonator. In one embodiment, the module measures 20.3 mm×14.8 mm×3.9 mm and the coaxial resonator is positioned on the circuit board of the module between a phase locked loop integrated circuit and a main section of the voltage controlled oscillator. The phase locked loop circuit includes a loop filter and is adapted to receive the frequency signal generated by the voltage controlled oscillator and generate an adjusted frequency signal.

Abstract: The present invention is, in one aspect, a radio frequency source, comprising a gyromagnetic precession oscillator. In a second aspect, the gyromagnetic precession oscillator comprises a closed, non-magnetic, cylindrical outer conductor defining a cavity therein; an axial field solenoid wound about the outer conductor; a non-magnetic, cylindrical inner conductor disposed within the cavity and coaxially aligned with the outer conductor; a plurality of cylindrical ferrite precessors, each defining a respective bore through which the inner conductor runs; a plurality of dividers disposed within and defining a resonant chamber in the cavity; and a dielectric material filling the cavity. In a third aspect, the radio frequency source is actively tunable. In a fourth aspect, the radio frequency source that is tunable pulse-to-pulse.

Abstract: A system and method for a novel microwave coaxial resonator oscillator using a ?ths wavelength resonator is described. The novel system and method provides a coaxial resonator for operation at high frequencies comprising a conductive resonator and a coaxial conductive outer shell electrically connected by an conductive end member, wherein the conductive resonator and outer shell are of a length approximately equal to (1/8+n/2) of the wavelength of the desired frequency, where n is a positive integer. The novel system and method provides a low noise oscillator for operation at high frequencies and reduces oscillator phase noise in high Q implementations. The novel system and method also provides for reducing the aspect ratio of a 1/8 wavelength coaxial resonator by increasing in a stepwise manner the length of the coaxial resonator by n/2 wavelengths of the resonator frequency, where n is a positive integer.

Abstract: A pulse generator includes a microwave source that delivers a pulsed signal into a resonant compression cavity equipped with a switching device for opening or closing the resonant compression cavity. The pulsed signal is stored in the resonant compression cavity when closed to be compressed therein before being delivered with a greater amplitude and a smaller width when the resonant compression cavity is open. The microwave source is of the amplifier type with an instantaneous bandwidth including the resonant frequency of the resonant compression cavity. The microwave source receives, at an input, an input signal to be amplified that is taken from the resonant compression cavity. Such a pulse generator can find particular application in high-power pulse generators.

Abstract: A circuit to generate antipodal PSK signal and a correlator circuit for recovering information from PSK (phase shift keying) UWB transmissions includes providing a circuit component characterized by a transfer function having alternating stable and unstable regions. By setting the operating point in a stable region or an unstable region, a non-oscillatory or an oscillatory output signal can be produced.

Abstract: An oscillator includes a resonance circuit, and a feedback circuit coupled to the resonance circuit. The resonance circuit includes a main resonance element circuit, and a voltage dividing circuit that divides an output voltage of the main resonance element circuit and applies a divided voltage to the feedback circuit.

Abstract: To provide a new data transmission system between a game device and related peripheral devices, and a device using same. Serial transmission data is divided into an odd-numbered bit sequence and an even-numbered bit sequence. Each bit of the odd-numbered bit sequence data is distributed respectively between pulses of a first pulse sequence signal having a constant interval, thereby forming a first pulse sequence signal (SDCKA). Each bit of the even-numbered bit sequence data is distributed respectively between pulses of a second pulse sequence signal having a constant interval, thereby forming a second pulse sequence signal (SDCKB). The respective time axes are adjusted such that the clock component of the first pulse sequence signal is located in the data section of the second pulse sequence signal, and the clock component of the second pulse sequence signal is located in the data section of the first pulse sequence signal.

Abstract: There is a manufacturing limit on how small ceramic coaxial resonators can be produced, which leads to a limit on the frequency of resonance for these resonators. One technique to quadruple the effective frequency of a ceramic coaxial resonator is to couple four resonators into a ring configuration, each of the resonators having an electrical length of 90°. Further, each of the resonators has an amplifier coupled in parallel, these amplifiers having phase shifts approximately equal to 90° and further being controlled by a tuning voltage VTUNE. In operation, four oscillation signals are generated at the same frequency but out-of-phase by a factor of 90°. When combined, the resulting signal is an oscillation signal at four times the frequency of the original oscillation signals. At the same time, one of the oscillation signals used in the combination can be sampled and be used for feedback purposes within a PLL-FS.

Abstract: A push—push oscillator is formed by (a) a resonator circuit including a transmission line having one-half wavelength and both ends of the line being left open, and a capacitance for frequency control coupled to the transmission line in parallel, and (b) two oscillators electrically identical to each other and their input sections being coupled to both the ends of the transmission line. Further, this oscillator can take out an output signal of even-order-harmonics from a midpoint of the transmission line in a transmitting direction as well as take out two fundamental waves from respective output sections of two branch oscillators. This push—push oscillator operating with a high frequency is downsized and simplified from a conventional one. Its phase-noise-characteristics and noise immunity are also improved.

Abstract: A signal generator for producing a plurality of signals having the same frequency but a constant phase difference includes first and second cavity oscillators coupled to each other via an appropriate wall and coupling apertures. A first output signal is extracted from the first oscillator at a first predefined location on the oscillator's outer wall, which location defines a first angle relative to the wall aperture which couples the first oscillator to the second. A second output signal is extracted from a predefined location on the outer wall of the second oscillator, which location defines a second angle relative to the aperture in the first oscillator. Because the two oscillators are coupled to each other, they will produce an output signal having substantially the same frequency. The phase difference between the two output signals is defined by the difference between the first and second angles.

Abstract: An improved method and system for generating quadrature phase shift keying signals for use in data transmission is provided. A pair of oscillators are slaved to the transmit frequency and produce two quadrature signal components with the same frequency but 90 degrees out of phase. The two signal components are carried to separate bi-phase switches by mirrored waveguides. Each bi-phase switch has a reflective waveguide coupler which directs the received signal into a waveguide terminated by a hard short and has a controllable shorting plane spaced approximately one-quarter wavelength from the termination point. The shorting planes are controlled by the output data signals and each introduces a 180 degree phase shift in the respective signal component when activated. The reflective couplers direct the selectively phase shifted signal components to an in-phase combiner, where they are combined to produce the quadrature phase shift keyed output signal.

Abstract: A discrete monotron oscillator for use in a high power microwave device is formed with a microwave oscillator having a half-wavelength resonant coaxial microwave cavity operating in fundamental TEM mode for microwave oscillation with an inner conductor defining a drift tube for propagating an electron beam and an outer conductor coaxial with the inner conductor. The inner conductor defines a modulating gap and an extraction gap downstream of the modulating gap. The modulating gap and the extraction gap connect the coaxial microwave cavity with the drift tube so that energy for the microwave oscillation is extracted from the electron beam at the extraction gap and modulates the electron beam at the modulating gap. For high power operation, an annular electron beam is used.

Abstract: The circuit employs two bipolar transistors, five resistors and a capacitor and can be primarily utilized as a broadband pre-amplifier and also as an oscillator or a mixer. A first transistor is connected to the circuit input and ground. A second transistor is connected to the collector of the first transistor and the supply voltage. One circuit output is connected to the second transistor. Another circuit output is connected to the first transistor via a resistor. The emitter of the first transistor is connected to the second transistor via a second resistor. A third resistor is connected between the base and collector of the first transistor. A fourth resistor is connected between the base and collector of the second transistor.

Abstract: An oscillator arranged to operate at an oscillation frequency includes a resonant structure 137, preferably a coaxial resonator, selected to resonate at a frequency, and an impedance 210, preferably a transistor 101 based common collector circuit, parallel coupled to said resonant structure 137, having a negative real part with a real magnitude and an imaginary part with an imaginary magnitude, said real magnitude being a function of said imaginary magnitude, said imaginary magnitude selected such that said real magnitude falls within 50% of a maximum at the oscillation frequency.

Abstract: A broadband, varactor-tuned shorted coax resonator is provided with a single point coupling port that facilitates coupling of discrete circuitry to the distributed resonator to form an oscillator. The coupling port is defined by adding a second shorted coax line across the end of the first. The outer conductors of the two lines are interconnected. The inner conductors of the two lines are serially coupled and define a coupling gap, either along their length or at their ends, across which discrete circuitry can be connected. In a preferred form of the invention, the discrete circuitry is positioned in a region within the periphery of one of the inner conductors in order to provide an electromagnetic shield for the circuitry.

Abstract: A broadband, varactor-tuned shorted coax resonator is provided with a single point coupling port that facilitates coupling of discrete circuitry to the distributed resonator. The coupling port is defined by adding a second shorted coax line across the end of the first. The outer conductors of the two lines are interconnected. The inner conductors of the two lines are serially coupled and define a coupling gap, either along their length or at their ends, across which discrete circuitry can be connected. In a preferred form of the invention, the discrete circuitry is positioned in a region within the periphery of one of the inner conductors in order to provide an electromagnetic shield for the circuitry.

Abstract: A crossed-field microwave power tube. Electrons are emitted from a tubular lectrode at ground potential. The electrons are accelerated by an electric field toward a high voltage anode located within the tubular electrode. A magnetic field is oriented along the axis of the tube; the magnetic field is perpendicular to the electric field. The electrons follow curved paths in the space between the tubular electrode and the anode, while producing electromagnetic radiation in a TEM mode. The TEM radiation is easily coupled from the tube.

Abstract: An IMPATT diode mounted in a double-tuned resonant cavity to exhibit stability by suppressing subharmonic frequencies is disclosed. A foreshortened quarter wavelength section is connected to the diode to form an equivalent parallel resonant circuit at one end thereof. At the other end of the quarter wavelength section is an odd-quarter wavelength tuning slug which provides a section which exhibits a second, series equivalent resonant circuit. To provide increased stability at subharmonic frequencies, a half-wavelength tuning slug is disposed adjacent to the odd-quarter wavelength section. The half wave tuning slug is virtually transparent at the operating frequency, but is a quarter-wavelength at the first subharmonic, and thus exhibits a high resistance at the subharmonic frequency.

Abstract: A solid state microwave power combiner is disclosed having a central combining cavity with a plurality of coaxial oscillator circuits disposed about and coupled to the cavity. The oscillator circuits are oriented such that their longitudinal axes are parallel with the central axis of the combining cavity. They alternate in configuration about the cavity such that adjacent oscillator circuits have their power generating diodes located on opposite sides of the cavity. In one embodiment, the coaxial lines used in the oscillator circuits have two parts of different sizes. The oscillator circuits are oriented about the cavity so that the smaller sized coaxial line part of one is adjacent the larger sized coaxial line part of the next. Both rectangular and circular combining cavities are disclosed.

Abstract: The means providing capacitive decoupling between the inside cylinder and a grid electrode are disposed at about one fourth of the wavelength of the highest operating frequency from the tube end of the inside cylinder. This is a current node, and dielectric losses at the highest frequency are thus greatly reduced. The match is less good at lower frequencies, but the corresponding dielectric losses are much less at lower frequencies. The first piston provides capacitive coupling between the first and second cavities whereby the entire outside cylinder may be maintained at ground potential.

Abstract: Improved output power performance is obtained in a millimeter-wave integrated-circuit (MIC) voltage-controlled oscillator by forming an output circuit and a bias input circuit in a suspended stripline configuration, which is subject to relatively low losses compared with microstrip designs. A Gunn diode and a varactor diode are mounted in alignment and in close proximity to each other. The suspended microstrip configuration includes a suspended substrate with a Gunn diode output circuit and a bias input circuit on one side, and a varactor diode grounding pad on the other face of the substrate. A sliding short-circuit device aligned with the Gunn diode output circuit provides tuning of the oscillator over a relatively wide range, and avoids having to trim the Gunn diode circuit components for final adjustment of the frequency.

Abstract: A small size and light weight microwave power generating apparatus in which a power MOS FET which can withstand a high voltage and large current is combined with a microwave transmission circuit having a drain side coaxial resonating system having an internal conductor connected to the drain of the MOS FET to be tuned under a cavity parallel resonating condition to an oscillating frequency and a gate side coaxial resonating system having an internal conductor connected to the gate electrode of the MOS FET and an external conductor connected to the internal conductor of the gate side coaxial resonating system via a variable capacitor. A high frequency oscillation (100-1000 MHz) is realized without the use of a magnetron by the internal capacitances C.sub.GS and C.sub.DS of the MOS FET.

Abstract: The invention is a microphonics suppression means for a high frequency resonant cavity. The resonant cavity is used in a RF oscillator to generate UHF/VHF frequencies. The resonant cavity comprises an outer wall portion, a center conductor portion, a tuning slug and a plurality of coupling probes. The coupling probes, tuning slug and center conductor are held in a fixed relationship by a microphonics suppression means made of a low dielectric material which fits over and around the center conductor and encapsulates the coupling probes and collars the tuning slug. The microphonics suppression means reduces the effect of microphonics on the output signal of the RF oscillator, thus allowing a clean output signal suitable for high power applications.

Abstract: A wideband VCO including a coaxial cavity with a negative impedance semiconductor diode and a tuning varactor mounted in a center conductor thereof. A variable bias circuit connected to the tuning varactor for tuning the VCO through a predetermined range. An output probe including a coupling varactor in contact with the center conductor. The variable bias circuit is coupled to the coupling varactor to alter the output coupling capacity as the frequency of the oscillator changes so that the output power remains substantially constant.

Abstract: An improved combiner of microwave power out of a plurality of coaxial diode oscillators is shown to be made up of a circular cylindrical cavity dimensioned to operate in the TM.sub.020 mode at a selected microwave frequency, with such oscillators being disposed about the periphery of both end planes of such cavity and each individual one of such oscillators being reentrant at an angle of 180.degree. so as to double the number of such oscillators as compared with the number of straight coaxial diode oscillators that may be disposed about the periphery of such cavity.

Abstract: A power combiner using a circularly cylindrical cavity, dimensioned to support the TM.sub.020 mode, to combine the power from coaxial diode oscillators is shown to comprise: (a) a first plurality of such oscillators disposed about the periphery of such cavity; (b) a second plurality of such oscillators disposed in coincidence with the first spatial null in the electric field in such cavity; and (c) a plurality, similar in number to the second plurality of such oscillators, of electrically conductive bridges interposed between the top and bottom walls of the cavity in-between the center conductors of the coaxial diode oscillators in the second plurlaity of such oscillators.

Abstract: A typical coaxial circuit which couples a negative resistance diode to the cavity of a power combiner consists of a metallic rod which is biased by a spring against the diode supported by a carrier which is effective to vary the position of the diode along the longitudinal axis of the rod. The rod cooperates with bores in a block to comprise, in series, between the diode and the cavity, a transmission line whose length varies in accordance with diode position, a fixed impedance transformer and a fixed length transmission line.

Abstract: A source of microwave-frequency electromagnetic energy of a specific desired frequency is generated by a device that utilizes a filter network to absorb energy of unwanted frequencies and couples energy of the desired frequency into a tunable ridge waveguide. The filter network is designed into the DC bias conductor to increase oscillator efficiency.

Abstract: A microwave oscillator circuit, suitable for use as the local oscillator in beam transmitters, radar systems and satellite TV receivers, comprises an active element (IMPATT, Gunn diode) at one end of a coaxial transmission line which is terminated at its other end by a matched load. At a suitable distance from the diode a high Q transmission cavity resonator is coupled to the transmission line via a first coupling hole.A drawback of such a circuit is that a portion of the oscillator power at the required oscillator frequency f.sub.o is dissipated in the terminal impedance Z.sub.o.This is obviated by coupling the transmission resonant cavity to the transmission line via a second coupling hole (12, FIG. 1 and FIG. 2). The distance between the first and the second coupling hole is 1/4.lambda..

Abstract: A mode filter apparatus for preventing unwanted modes in a multi-moded structure utilizing a radial plurality of resonant slots on the bottom of the filter cavity. The top of the filter cavity includes a variable height center section to provide mode selectivity in cooperation with the resonant slots.

Abstract: The components of a transistor oscillator are mounted on an end cap rotatably mounted on the outer tube of a cavity resonator which stabilizes the oscillator. The intensity with which a high frequency is applied to the cavity resonator is adjustable by rotation of the end cap.

Abstract: A high frequency industrial generator, especially suitable for supplying power to a device for heating an electric poorly conducting substance such as a fleece of a cellulose material, comprises two hollow concentrically disposed conductors each of square section and supporting respective electrode plates of an associated capacitor. All the plates are vertically disposed and lie at right angles to the walls of the respective conductors. In the middle of the electric plates there is situated a triode electron tube electrically connected to the plates to form an oscillating circuit. The anode potential and cooling water supply for the electron tube is located within a field free space inside the internal conductor. One set of electrode plates can be adjusted relative to the other to adjust the frequency and the arrangement ensures only low electrical losses are incurred.

Abstract: A microwave power combiner is shown to consist of a plurality of coaxial diode oscillators disposed on the periphery of a circularly cylindrical cavity operating in the TM.sub.020 mode, such cavity containing mode suppressor means to prevent any mode other than the TM.sub.020 from operating.

Abstract: The specification describes a solid state microwave power combiner wherein a plurality of solid state power generating devices are mounted between adjacent conical support and housing structures. These structures define the microwave electrical circuits for these devices, and also as provide a waveguiding region for propagating energy from these devices to a common output line. Both the support and housing structures have their apexes integrally joined, respectively, to input and output conductors of a common output coaxial line used for coupling power out of the combiner. This novel geometrical configuration minimizes the electrical distance between the power generating devices and the coaxial output line, maximizes the packing density of the structure and optimizes the electrical performance of RF termination elements for these devices.

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: In an oscillator or power combiner of the type operating at microwave, millimeter wave and above, apparatus for increasing the size, so that one or more active devices can be coupled to the oscillator, including a TM coaxial cavity operating at a predetermined frequency, which cavity has an output coupled thereto for removing power, and a second cavity operating at a dominant mode and coupled to the TM coaxial cavity, which second cavity assures efficient and spurious free operation of the oscillator or power combiner at the desired frequency.

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: A power combiner for solid state oscillator circuits is shown to be the combination of a central cavity and a plurality of subcavities, each one of the latter being dimensioned to operate in the TM.sub.010 mode to synchronize a plurality of solid state oscillator circuits. The central cavity and each one of the plurality of subcavities are coupled together through coaxial lines so that the central cavity in turn synchronizes the plurality of subcavities.

Abstract: In an oscillator of the type producing microwaves, millimeter waves and above, apparatus and a method for increasing the size, so that one or more active devices can be coupled to the oscillator, including a first cavity operating at a higher order mode, which cavity has an output coupled thereto for removing power, and a second cavity operating at a dominant mode and coupled to the first cavity, which second cavity assures efficient and spurious-free operation of the oscillator at the desired frequency.

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: 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: A broad-band cavity-tuned transistor oscillator includes a field effect device having capacitive feedback from source to drain and having a gate capacitively coupled to a cavity for producing an output signal that is frequency selectable according to cavity resonance, which resonance is determined by translation position of a mechanical tuning plunger coupled to the cavity and the degree of capacitive feedback.

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.