Abstract: A millimeter wave microstrip transmission line is coupled to a solid state echanically tunable cylindrical resonating coaxial cavity millimeter-wave oscillator by means of a probe extending linearly from the microstrip through an access slot in the cylindrical cavity wall into the zone of optimum electric field strength in the oscillator cavity to effect the translation of a TEM wave from the resonating cavity to the microstrip line at optimum power transfer and without wave mode change.

Abstract: A very high frequency oscillator (4-22 GHz) including field effect transistor and first and second YIG sphere resonators whose reactant frequencies are displaced, which gives the oscillator a wide frequency range. The first YIG sphere is doubly coupled to the source and gate of the transistor, which gives the oscillator good linearity (.perspectiveto.10.sup.-3) over its frequency range. The second YIG sphere is coupled to the gate by a coupling wire which also couples to the first YIG sphere.

Abstract: Microwave dielectric resonator apparatus which, for example, may be a microwave oscillator frequency stabilized by a dielectric resonator or may be a microwave filter whose critical frequency is determined by a dielectric resonator, has the dielectric resonator environmentally protected in a hermetic chamber. As the hermetic integrity of the chamber would be destroyed by having a tuning slug therein at the end of a screw threaded into a tapped hole through a chamber wall for rotation by a screwdriver outside the chamber, the tuning slug is instead located within a non-hermetic chamber at the end of a screw threaded into a tapped hole through a wall of the non-hermetic chamber serving also as an outer wall of a housing enclosing both chambers. The chambers have an interface which is transparent to microwave fields and proximate the dielectric resonator and tuning slug.

Abstract: A tuned oscillator is disclosed which comprises an active element, a resonator electrically connected to the active element and made of a magnetic material using ferro-magnetic resonance phenomenon, and a magnetic circuit for applying a magnetic field to the resonator. The resonator is made of an YIG (yttrium, iron and garnet) thin film magnetic resonance element formed by a thin film forming technique and utilizes an uniform mode ferro-magnetic resonance in the YIG thin film, and operating under the application of magnetic field of the magnetic circuit.

Abstract: A improved microwave dielectric oscillator module which is provided with a removable temperature compensated dielectric resonator channel element is described. The removable temperature compensated dielectric resonator channel element cooperates with an electrically shielded housing. A substrate is mounted within the housing. Microstrip or stripline conductive patterns deposited on the substrate couple energy from the removable dielectric resonator to the remainder of the oscillator circuitry. The oscillator achieves wideband operation utilizing a GaAs FET transistor as the oscillators active element in conjunction with an intergral trombone-line phase adjuster.

Abstract: A directly modulated microwave source for use in communications equipment is disclosed. The arrangement, fabricated in an open ended waveguide comprises an oscillator section operating in the TE.sub.101 mode and an impedance matching section providing adjustable coupling to a load. A suitable active element is a Gunn diode, post mounted in proximity to the closed end of the waveguide for H field coupling. Modulation in frequency or phase is achieved by a varactor diode, also post mounted, positioned approximately 2/3 of the length of the waveguide from the closed end. A vertically adjusted post for the load coupling adjustment, is placed adjacent the varactor post, but nearer the opening. The two adjacent posts define the boundary between sections and provide H field coupling to the varactor diode. Temperature stabilization means and frequency tuning means are located respectively on the upper and lower surfaces of the waveguide at anti-nodial portions of the oscillator section.

Abstract: A microwave cavity oscillator comprises a waveguide blocked at both ends, an active device enclosed in the waveguide and a dielectric powder or other fluid filling the remaining space in the waveguide. The microwave cavity oscillator is useful, for example, as in a discontinuity detector system.

Abstract: The interior of a metal housing is divided by a dielectric substrate into two compartments. At least one of the compartments is kept air-tight. The substrate carries thereon a semiconductor active element chip for oscillation within the air-tight compartment and a dielectric resonator within the other compartment. The chip and the resonator, electromagnetically coupled with the chip, constitute a microwave oscillator whose oscillation frequency can be stabilized. A metal screw is threaded into that wall of the housing which defines the other compartment in a predetermined positional relationship to the resonator. The metal screw is rotatable to vary the distance between the screw and the resonator and, thereby, the oscillation frequency.

Abstract: An oscillator-mixer arrangement including a dual-gate field effect transistor of the Schottky type for supplying an intermediate frequency output signal. The output signal is obtained by subtractively mixing a high frequency input signal and a signal produced in the arrangement. The input signal is applied to the first gate electrode (G.sub.1), the produced signal is controlled by the second gate electrode (G.sub.2), and the output signal is recovered at the drain electrode (D), while the source electrode (S) is directly connected to ground. A micro-strip line having a characteristic impedance Z.sub.O which is electromagnetically coupled to a dielectric resonator and loaded by an impedance (Z.sub.O) is connected to the second gate electrode (G.sub.2). The arrangement is intended to be included in a receiver front end assembly for very high frequency waves, typically of a frequency of 12 GHz, used for broadcasting radio-television programs by artificial satellites.

Abstract: A rotatable tuning body is driven by a positioning motor such as a stepper motor, for varying the tuning frequency of a magnetron. The motor rotor is situated within the evacuated space of the magnetron and is integrated with the tuning body. The motor stator is fixed to the magnetron envelope, and preferably forms part of the vacuum-tight envelope.

Abstract: An apparatus and method is disclosed for providing a planar disc resonator oscillator/amplifier which consists of a planar radial disc resonator, a substrate having a hole extending therethrough, a negative impedance device, and a conductor having a predetermined width. The oscillator/amplifier having an external quality factor dependent upon the width of the conductor and upon the distance between the centers of the planar radial disc resonator and the negative impedance device.

Abstract: A dielectric resonator stabilized oscillator structure and method for adjusting the oscillating characteristics of the oscillator which includes mounting the dielectric resonator to a cover housing member which can be positionally varied to move the resonator in a plane parallel to a semiconductor device and transmission line circuitry comprising the oscillator. The semiconductor device and transmission line circuitry are disposed within a bottom housing assembly to which the cover housing member is fixedly mounted to after adjustment and optimizing of the oscillator characteristics is conducted. The cover member includes openings therethrough which are oversized with respect to corresponding threaded openings in the bottom housing assembly thereby allowing the adjustment of the dielectric resonator by moving the cover member while screws are threaded through the openings thereof into the bottom assembly and also fixedly mounting of the cover member to the bottom assembly.

Abstract: A filter reflection image guide oscillator and a line scanning device. The device includes a brass metal heat sink base on which a dielectric waveguide is mounted. A resonant cavity is defined in the dielectric waveguide and an oscillator diode, Gunn or IMPATT, for example, is located in the resonant cavity. The resonant cavity is enclosed by a metal cover with a post which is made to extend into the resonant cavity to contact one electrode of the oscillator diode. The top surface of the waveguide includes a perturbation surface consisting of parallel and spaced metal stripes which are laterally positioned along the length of the waveguide. The spacing of the metal stripes defines the function performed by the device. When the stripes are at 1/2.lambda..sub.z spacings (.lambda..sub.z is the guide's longitudinal wavelength), a filter reflection image guide oscillator is provided and the perturbation surface is non-radiative. Only a small portion of the energy radiates out of the front of the waveguide.

Abstract: A microwave solid-state oscillator includes a casing hermetically enclosing a microwave oscillation device and a dielectric resonator electromagnetically coupled with the microwave oscillation device, an output terminal leading out an oscillation output from said casing, and a microwave terminal electromagnetically coupled to the dielectric resonator, one end of which is connected to a microwave line having a terminating admittance at the outside of the casing.

Abstract: A millimeter wavelength oscillator combining a mechanically tunable resonating cavity oscillator element with an electronically tunable solid state diode element provides a basic stable steady wave energy source with fine-tuning capabilities not possible with a resonating cavity oscillator alone, and with an apparatus structure which is light in weight, compact, mechanically sturdy, and with easily accessible and quickly replaceable component parts.

Abstract: An electronic varactor tuner is integrally combined with a mechanically tuned Gunn oscillator to provide an increased tuning range in a light weight, compact, rugged combination with easily and quickly replaceable components.

Abstract: A power combiner circuit for combining a plurality of signals to provide output power to a load over a broad range of operating frequencies includes a resonant cavity and a plurality of negative resistance diodes which couple such signals into the resonant cavity. Each one of the negative resistance diodes is disposed in a corresponding one of a like plurality of coaxial oscillators. In a first embodiment of the invention, the end of the cavity coupled to the load includes a plurality of members which provide a plurality of resonant structures and which are used to reduce variations in the impedance of the cavity over the operating range of frequency. In a second embodiment of the invention, each one of the coaxial oscillators includes a plurality of ring members used to match the impedance of the diode to that of the cavity and to reduce variations in the impedance of the cavity over the operating range of frequency.

Abstract: A box-shaped metal microwave oscillator is provided having two pairs of substantially parallel, confronting inner surfaces, the second pair perpendicular to the first pair to define an oscillator cavity. The forward end of the cavity is walled off with a slotted wall to permit only a portion of the oscillator energy to be emitted. The spacing of certain of the walls and the location of the oscillator components to the wall is described.

Abstract: The spatial power combiner disclosed here is used to efficiently combine the power sources, which incorporate two-terminal negative resistance devices, in a coherent manner such that a high power output with a stable and definite frequency and phase is obtained, the sources to be combined being arranged in an array configuration.

Abstract: An integrated circuit tunable cavity oscillator for extremely high freque operation in image line waveguide. The oscillator includes a metal base with a cylindrical bore, a dielectric or semiconductor waveguide mounted atop the metal base and having a bore which is continuous with the metal base bore. A Gunn or IMPATT diode is assembled in the metal base bore on top of a drum which is urged upwards toward the waveguide bore by a spring located behind the drum. From above, cavity tuning means including a top disk and a threaded screw cover the waveguide bore and push the diode into the metal base bore to define the cavity height of the coaxial cavity of the oscillator. The waveform, which is set up in the recessed cavity in the metal base, is launched into the waveguide. Thus, a ruggedized, low cost, tunable (by a tuning screw) and low weight oscillator for millimeter wave image line or microstrip operation is obtained. Furthermore, the oscillator diode and cavity defining hardware are easily replaceable.

Abstract: A stable, low noise voltage-to-current converter is provided to control the tuning current in YIG tuned devices such as YIG tuned transistor oscillators. The circuit provides stable tuning current which is substantially noise free.

Abstract: An oscillator formed in a rectangular waveguide (1) with both mechanical and electronic tuning comprises an oscillator device (4) spaced from a movable short-circuit termination (2) with a varactor diode (5) therebetween, the effective electrical spacing between the oscillator device (4) and the varactor (5) being approximately an integral number of half-wavelengths at the operating frequency. The varactor (5) extends into the waveguide (1) from one broad wall thereof and engages a transverse member (10) extending between the narrow walls so that only part of the height of the waveguide (1) at that region is obscured. This enables the operating frequency and hence the extent of coupling of the varactor (5) to the oscillator cavity, and thus the electronic tuning range, to be varied by adjusting the position of the short-circuit (2).

Abstract: An oscillator having the ability to oscillate at a plurality of discrete frequencies in response to an applied digital signal is disclosed. A crystal-controlled, resonant circuit utilizing passive components as frequency determining elements and a PIN diode switching scheme allows the oscillator to demonstrate a tendency for each of the plurality of discrete frequencies to drift equally in response to temperature changes. A two-transistor, emitter coupled amplifying section uses a current mirror for biasing and provides an impedance matching network.

Abstract: An oscillator includes two transistors or like devices having their emitters connected to a common of a power source. The two transistors or like devices are interconnected with the base of the first connected to the collector of the second and the base of the second connected to the collector of the first. An inductance is placed across the base-collector connectors and a circuit through the oscillator is completed via a lead to one of the base-collector connectors.

Abstract: A microwave oscillator suitable for millimeter wavelengths comprises a Gunn diode (3) coupled to a waveguide (1) by a resonant-cap structure (5,6). The diode (3) generates microwave energy both at a fundamental frequency f.sub.o which is below the cut-off frequency of the waveguide (1) and at a second harmonic frequency 2f.sub.o above cut-off. To control the generation of microwave energy at 2f.sub.o, energy at f.sub.o is coupled into the waveguide (1) from an adjacent further waveguide (9) above its cut-off, by means of an electric probe (8) extending close to the cap (5). The probe (8) may couple in a locking signal at or close to the free-running value of f.sub.o from another oscillator having better noise performance and electronic tuning, thereby locking 2f.sub.o to twice the frequency of the locking signal, or alternatively may couple to a varactor-tuned cavity resonant at f.sub.o.

Abstract: In a distributed IMPATT structure, power is coupled out through a side contact. That is, in previously proposed distributed IMPATT structures, the gain medium (the active region of the IMPATT) operates as a transmission line. The prior art has attempted to couple output power from the gain medium through an end contact, i.e., through a contact which is perpendicular to the primary direction of energy propagation (and also to the direction of maximum elongation) of the active medium. In the present invention, a sidewall contact extends in a direction which is parallel to the principal direction of propagation of the energy in the active medium. Thus, the sidewall contact plus the active region together can be considered as a single transmission line. This extended transmission line is also connected to a second distributed semiconductor element which functions as a varactor.

Abstract: The invention relates to an ultra-high frequency oscillator (11-14 GHz) having a plurality of transistors, stabilized on at least one of their electrodes by a microstrip line coupled to a dielectric resonator. The oscillator according to the invention groups the transistors on the periphery of an insulating substrate, which centrally supports a single dielectric resonator common to all the transistors. The microstrip lines have two end portions, which are not coupled and are parallel to the field lines of the resonator, and a coupled central portion, perpendicular to the field lines. The transistors and microstrip lines are coplanar. The output is by a coaxial cable at the center of the substrate or by a microstrip line coplanar to the substrate.

Abstract: A double dielectric resonator (1) having lower and upper preferably cylindrical dielectric elements (3, 5, respectively) is used to stabilize an oscillator operating at microwave frequencies. The dielectric elements (3, 5) are separated by a distance (d) which is greater than zero but less than an amount that will eliminate magnetic coupling between the dielectric elements (3, 5), and preferably less than an amount that will push the oscillator into a nonlinear region of the frequency versus separation (d) curve. The major axes (43, 45, respectively) of the dielectric elements (3, 5) are aligned, or else parallel but offset slightly. The invention may be used with reflection type, parallel feedback, and series feedback oscillators.

Abstract: A stabilized microwave oscillator having a selected operating frequency range, composed of a rectangular waveguide dimensioned to have a cutoff frequency above the selected operating frequency range, at least one active semiconductor element and components connected for supplying a direct operating voltage to the element, mounted in the rectangular waveguide, a transmission resonator, and a coupling device coupling the rectangular waveguide to the resonator, the coupling device including a waveguide section having a length of about .lambda./2, where .lambda. is the wavelength of the center frequency of the operating frequency range, and dimensioned at least in part to operate as an evanescent mode waveguide and/or a waveguide having a cutoff frequency in the vicinity of the upper end of the selected operating frequency range.

Abstract: A microwave cavity oscillator has a semiconductor device, for example a transistor for exciting the cavity to oscillate. The device is mounted upon a substrate which is itself mounted, conveniently soldered, upon a carrier which is releasably secured in a chamber adjacent the cavity. The carrier and substrate are mounted so that the device is coupled to the cavity via a hole extending therebetween and can be removed and installed as a sub-assembly to facilitate tuning and other adjustments in a test bed. In preferred embodiments one end of the carrier is located in spigot-and-socket fashion in a recess surrounding a hole communicating with the cavity. The other end of the carrier is urged by spring means to positively and accurately locate the carrier relative to the cavity. A part of the substrate extends through the hole and into the cavity. The transistor is mounted on the part within the hole and the part within the cavity serves as a capacitive coupling probe.

Abstract: An improvement in a microwave oscillator using a GaAs FET as the active element is shown to include a phase detector responsive to a portion of the positive feedback signals applied to a resonator having a high Q and to a portion of the signals out of the GaAs FET, shifted by 90.degree., to obtain signals to degenerate noise internally formed in the GaAs FET.

Abstract: A modulated elongate cavity oscillator with minimized modulation nonlinearities includes a first cavity having dimensions which determine the fundamental resonant frequency of the oscillator, a gain element disposed in said first cavity that provides amplification to sustain oscillation, and a varactor diode disposed in said first cavity for modulating the fundamental frequency. A first waveguide is coupled to the first cavity for absorbing modes higher than the mode of the fundamental frequency which have an electric field maxima concurrent with the longitudinal center line of the first cavity. A second waveguide is coupled to the first cavity for absorbing modes higher than the mode of fundamental frequency which have an electric field minima concurrent with the longitudinal center line of the first cavity, whereby the first and second waveguides provide effective attenuation of higher order modes such that modulation nonlinearities due to the existence of higher order modes are substantially eliminated.

Abstract: A stable electromagnetic oscillator (30) comprises an amplifying element (3) in feedback association with a dual mode resonant cavity (12) that provides a double pole bandpass filter function. Two orthogonal modes (1 and 2) of electromagnetic energy resonate within the cavity (12). An output from the amplifying element (3) excitationally couples into the first mode (1), while the second mode (2) couples into the input of the amplifying element (3). The output (8) of the oscillator (30) is obtained from the first mode (1). Optional injection lock can be used for greater stability by means of coupling a stable a.c. reference (9) into the cavity (12) in alignment with the second mode (2). Optional electronic frequency tuning comprises a phase or frequency comparator (11) and a reference a.c. source (13), producing a d.c. feedback signal fed to varactor diodes (10). Coupling ports (4, 5, 6, 7) of the cavity (12) can be, e.g., irises, capacitive probes, coaxial probes, or any combination thereof.

Abstract: The oscillator includes a two-terminal device (1) as an active element and an impedance-matching network (4) for matching the two-terminal device to a load (A). The impedance-matching network is formed by a coupler (4) having four terminals (2, 3, 7, 8) two of which (7, 8) are terminated with impedances (5, 6) whose values are chosen depending on the output power or frequency to be adjusted or are varied as desired. Another of the terminals is connected to the active two-terminal device (1), and the fourth terminal (3) is the oscillator output.

Abstract: A microwave oscillator with TM01.delta. dielectric resonator is disclosed. The oscillator operates with a TM01.delta. mode as contrasted with prior art techniques of TE01.delta. mode. This provides for an improved tuning range in excess of 10% of the operating frequency.

Abstract: Two collocated, weakly coupled probes, on loop and one dipole, detect the magnetic and electric fields inside a maser cavity. Signals from the probes are compared in phase, and the signal output from the phase detector is applied to a varactor, the reactance of which is coupled into the cavity by a microwave coupler. Alternatively, the varactor may be placed inside the cavity. Any deviation of phase from 90.degree. as detected by the phase detector will then produce an error signal that will change the reactance coupled into the resonant cavity to change its reactance, and thus correct its resonance frequency. An alternative to using two probes is to use a single disk probe oriented to detect both the magnetic and electric fields, and thus provide the error signal directly.

Abstract: Magnetic circuit for an yttrium-iron garnet crystal (11) resonator for an oscillator, formed by a first cylindrical pole piece (12) comprising a coil (13) provided around an axial core (14) and a second cylindrical pole piece (15) having a flat bottom (16), the yttrium-iron garnet crystal (11) being placed in a gap (17) defined by an end (18) of the axial core (14) and the part (19) of the flat bottom facing the end (18). According to the invention, a circular groove (20) is arranged in the flat bottom (16) around the part (19) facing the end (18) of the axial core (14).

Abstract: A planar oscillator (9, 109) having a dielectric cavity (25, 125) and which is operative at microwave frequencies, said oscillator consisting of a dielectric material base (10, 110) one surface of which has, superposed thereto, a continuous layer (11,111) of a conductive material which coats portions of said face; the remaining portions (10A, 10B, 110A', 110A", 110B) of the surface have, superposed thereto, strips of a conductive material (12,13,14,112,113,114) which are separate from each other and are electrically connected to an active element (19, 119), a dielectric cavity (25,125) adhering to the opposite surface of the dielectric material base (10,110), the layer of conductive material (11,111) providing a grounding plane and the strips of conductive material (12,13,14,112,113,114) providing transmission and output lines for the oscillator.

Abstract: A primed oscillator for microwave amplification includes a single tank conductor (16) coupled to a coupling conductor (17) by an interdigitated coupler (26). The coupling conductor (17) is connected to the cathode of an IMPATT diode (22) which is triggered by the application of a back-biasing trigger pulse that biases it into its negative-resistance region. When a keying pulse is applied to the IMPATT diode (22), the diode couples power through the interdigitated coupler (26) to the tank circuit (16) to cause oscillations that are initially in phase with any incoming signals, but the frequency of the oscillations is determined by the configuration of the tank circuit (16), not by the frequency of the incoming signal. If the incoming signal is near enough to the resonant frequency, and if the duration of the keying pulses is short enough, the output of the primed oscillator appears to a band-limited receiver to be an amplified version of the input signal.

Abstract: Stray capacitance is reduced in a wideband tunable oscillator network by arranging the resonant circuit as one or more series circuit branches wherein a variable capacitance such as a varactor diode is interposed between two substantially identical inductors. In the disclosed VHF-UHF oscillator, the inductors are realized by TEM transmission lines of the stripline variety. The stripline is formed by a multilayer printed circuit board arrangement and two resonant circuit branches are interconnected in a manner that permits biasing of the varactor diodes without the use of blocking capacitors in the resonant circuit path.

Abstract: A transmission line microwave oscillator having two degrees of freedom wherein the real portion, R.sub.in, of the input impedence seen by the active device is adjustable by changing the coupling coefficient between and active device and a resonator and where the external quality, Q.sub.EXT, of the oscillator is adjustable by changing the coupling between the resonator and an output transmission line.

Abstract: A distributed inductive reactance is coupled to a terminating impedance at the interface of a combiner probe with a resonant cavity. The distributed reactance is implemented by a metal insert having a cavity interface and having a coupling portion, which is coaxial with a cylindrical dielectric and with a cylindrical cavity in an end of the terminating impedance.

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 frequency stabilized oscillator includes a rectangular resonant cavity having a ground or short circuit wall, an H wall, and a top wall having an inductive window therein. A solid-state oscillating device such as a GUNN diode is attached at one end thereof to the short circuit wall, and a disk type dielectric resonator is supported from the short circuit wall and is located substantially adjacent the solid-state oscillating device so as to electromagnetically couple with the oscillating device. The inductive window is located so as to be in substantially overlying relationship with the dielectric resonator. A strip conductor is attached to the upper end of the oscillating device and extends through the H wall to the exterior of the oscillator to thereby provide a DC supply terminal for the oscillating device. The H wall of the resonant cavity is isolated from the DC supply applied to the strip conductor by means of a thin insulating layer between the strip conductor and the H wall.

Abstract: A very simple oscillator circuit, using a FET pair with RF coupled, DC isolated gates, selectively operates at two widely separated microwave frequencies. The two FETs are DC isolated so that one of them can be pinched off (to act as a passive element) while the other remains active. Thus, for example, a two-FET push-push oscillator operating at 20 GHz can switch downband, when one FET is pinched off, to act as a fundamental mode oscillator at 121/2 GHz. The circuit is integrable. In alternative embodiments, more than two FETs are used, for switching over a wider frequency range when one or two of them is pinched off.

Abstract: The microwave oscillator, including a transistor (1), e.g. a field-effect transistor, includes a first resonating circuit (2) connected to a first terminal and a second resonating circuit (3) connected to a second terminal of said transistor, each resonating circuit including a microstrip (4,6), to which is coupled a dielectric resonator 5,7, both resonators of both resonating circuits being similar and operating at the same resonating frequency, third terminal of said transistor defining a power output. The oscillator provides two outputs of lower power but with a high Q.sub.ext, and an output of higher power with a medium Q.sub.ext.

Abstract: A proximity detection system is disclosed including an oscillator circuit which has an electromagnetic resonator characterized by a hollow metallic chamber, an oscillator having negative resistance characteristics fixed in the chamber, and a source of direct current connected in series with the oscillator and the chamber. A radiating iris opening is provided in the chamber of a size and disposition such that oscillation of said oscillator circuit means is damped except in the proximate presence of an object before the iris. A detector responsive to a characteristic change in output in the oscillator circuit produced by the oscillation thereof such as an operational amplifier or comparator produces an output indicative of the presence of an object.

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 microwave oscillator has a cavity resonator enclosed by conducting walls and containing a microwave oscillator element therein. A biasing device applies a bias voltage to the microwave oscillator element to generate a microwave signal. A microwave coupling circuit takes the microwave signal from the resonator in a direction which is perpendicular to the direction of the propagation of the microwave signal in the resonator and applies the taken-out microwave signal to an output means. The microwave coupling circuit is located at a position corresponding to one of the nodes of the electric field appearing in the cavity. The coupling circuit also is preferably at a position on the resonator wall which is a quarter wavelength away from the oscillator element. The undesired signals can be effectively suppressed in the output means, by -44 dB, or more, without making use of a filter.

Abstract: A length of conventional hollow waveguide having an interior rectangular cavity has openings in the broad walls along a common axis. A diode support structure positions a negative resistance diode in the waveguide through one opening. A DC bias conductor structure positions a bias conductor through the other opening and into contact with the diode to provide a DC bias thereto. These two structures are secured together and to the conventional waveguide structure.