Abstract: A dielectric resonator oscillator utilizing transmission-type injection-locking for frequency stabilization is disclosed as including a transistor, two microstrip lines, and a dielectric resonator. One microstrip line is coupled to the transistor, while the other microstrip line receives the broadband signal. The dielectric resonator is positioned adjacent to and between the first and second microstrip lines and is operable for coupling an injection-locking signal into the transistor for locking the oscillation frequency of the oscillator. The two microstrip lines are preferably oriented at right angles so that various sizes of the dielectric resonator can be accommodated.

Abstract: A voltage controlled oscillator is tuned with a network comprising two varactor diodes and two transmission lines. By selecting appropriate values of varactor capacitance and transmission line length and width the overall reactance of the network is such that, when a varactor tuning voltage is varied, the output frequency of the voltage controlled oscillator will vary in an fashion with respect to the tuning voltage. Such a voltage controlled oscillator is gain compensated and exhibits a controlled modulation sensitivity over a range of frequencies. If the required frequency range of the oscillator is known beforehand, an alternate embodiment of the invention may be employed in which one of the varactor diodes is replaced with a fixed capacitor having a suitable value for the desired frequency range.

Abstract: In a dielectric resonator controlled oscillator with frequency multiplication, a line (12) has an open end and another end connected to a gate electrode of an FET (11) with a dielectric resonator (13) electromagnetically coupled to the line at a location along a total length of the line. The total length is selected to make a combination of the line and the dielectric resonator have a substantially zero impedance for a higher harmonic frequency when seen from the gate electrode. More specifically, the total length is selected so as to be equal to about three quarters of a wavelength which a frequency multiplied oscillation, such as a frequency doubled oscillation, has in the line. The location is selected so as to optimize the oscillator for a fundamental oscillation of a fundamental frequency determined by the dielectric resonator.

Abstract: A microwave oscillator has a sealed, dielectric case that encloses a dielectric resonator adjacent a circuit conductor. Discrete conductive elements are removably mounted to the exterior of the case within a magnetic field generatable by the resonator. The oscillator may be tuned by selectively removing the discrete conductive elements from the case.

Abstract: A high-frequency modulator which is linearly modulated in a frequency range around a center frequency and comprises a high-gain field effect transistor whose output is fed-back to the input from a coupler constituted by two relatively fine lines which are sufficiently remote from each other to provide that at the input of the transistor the majority of the high power available at its output is reinjected, and thus a high external Q factor is obtained. The modulation circuit which is arranged in parallel with the feedback network includes a varicap which is arranged in series with three line elements and a fixed capacitor calculated for optimizing the linearity of the frequency modulation as a function of the control voltage of the varicap. The circuit may be used for example, in equipment such as radio altimeter sources or proximity fuses, auto-directional systems and long-range radar.

Abstract: A microwave oscillator of the type in which a dielectric resonator is disposed inside a conductive housing, characterized in that a conductive rod-like member is disposed inside the housing and arranged in parallel with the axis of the dielectric resonator with one end connected electrically to the housing and the other end left free. Preferrably, the rod-like member is made so thin as to interrupt little the magnetic flux generated by the dielectric resonator, and the resonance frequency of the housing is selected lower than that of the dielectric resonator.

Abstract: A band reflection type oscillator includes a GaAs-FET having a source, a gate and a drain in which the drain is connected to ground. A stripline is connected to the gate, and a dielectric resonator is provided adjacent the stripline in a magnetically coupled relationship therewith. A stripline stub is electrically connected to the drain and positioned adjacent the resonator in a magnetically coupled relationship therewith, thereby defining a positive feedback circuit through the drain, said stripline stub, the resonator and the stripline to the gate. By the positive feedback circuit, the oscillation stability is improved.

Abstract: A dielectric resonator microwave oscillator in which the gate of a FET is connected to a resonance circuit. An inductor is connected to the drain of the FET, and the output is taken from the source of the FET. This dielectric resonator microwave oscillator has enhanced negative resistance and positively starts the oscillation even when there is a low reflection coefficient of the resonance circuit. Using a circuit which consists of a capacitor and inductor between the source and the output terminal, a further increasing of negative resistance at the gate of the FET is obtained.

Abstract: A signal converter comprises a filter formed of a first ferromagnetic resonator which supplied with an input signal that is to be converted and produces a filtered signal having a first frequency, a local oscillator formed of an active element and a second ferromagnetic resonator connected to the active element, produces an oscillating signal having a second frequency, a mixer receives and mixes the filtered signal and oscillating signal and produces a converted signal, the first ferromagnetic resonator is formed of a first ferrimagnetic crystal, a microstrip line magnetically coupled to the ferrimagnetic crystal and a first D.C. bias magnetic field means which applies a first D.C. bias magnetic field to the first ferrimagnetic crystal, the second ferromagnetic resonator is formed of a second ferrimagnetic crystal, a second microstrip line is magnetically coupled to the second ferrimagnetic crystal, and a second D.C. bias magnetic field means which applies a second D.C.

Abstract: A microwave frequency oscillator capable of being linearly swept over a wide frequency range around a central frequency comprising a field-effect transistor with a high gain, the output of which is fed back to the input from a coupler consisting of two relatively narrow striplines located close together. A wobbulator circuit is fitted in shunt to the feedback network comprises two voltage variable capacitors in series between three line components designed to optimize the frequency modulation linearity in relation to the voltage variable capacitance diode control voltage. The oscillator is useful in equipment requiring extreme linearity such as radio-altimeter sources.

Abstract: An oscillation circuit comprises a resonator and frequency switching means for switching oscillating frequencies of the resonator, said frequency switching means including a capacitor and an electrical switching element in series, said electrical switching element having a small capacitance as compared to that of said capacitor and a conductive voltage larger than a peak voltage of the oscillation circuit output applied across the electrical switching element. Preferably, the electrical switching element is a diode.

Abstract: A self-oscillating mixer is disclosed, and includes two bipolar transistors coupled as a Darlington pair, where the base of the first transistor receives an input signal, and where the common collectors of the transistors generate an output signal; and a feedback resonator operable for coupling signals at the local-oscillator frequency from the output side of the transistors to the input side of the transistors. Such a self-oscillating mixer can provide signal conversion gain at microwave frequencies.

Abstract: A UHF oscillator circuit includes a plurality of first leadless, or "chip", surface mounted components machine positioned on a first side of a printed circuit (PC) board and a plurality of second lead-bearing components mounted on a second side of the PC board and coupled in circuit through the PC board to the chip components in an arrangement which substantially reduces circuit fabrication costs. Comprised of a majority of automatically positioned surface mounted chip components and making use of a minimum number of lead mounted discrete components, the low Q values of the surface mounted components are compensated for by an external surface mounted feedback capacitor coupled across the collector-emitter junction of a common base transistor to provide oscillator tuning over a frequency range greater than an octave.

Abstract: An oscillator with a dielectric resonator capable of providing a designated output and being suited for mass production comprising an insulating substrate, a strip structure, a dielectric resonator located adjacent to the strip structure, the last two being mounted on the substrate, and an oscillatory transistor connected to one end of the strip structure. The strip structure consists of two spaced strip sections interconnected by an electrically-conductive bridge-shaped connector section having a conductor part, which is located further away from the insulating substrate and closer to the dielectric resonator than the two strip sections.

Abstract: A microwave oscillator having very low phase noise characteristics has a reflection oscillator circuit coupled to a right-circular cylindrical resonant cavity designed to operate in the TE.sub.011 mode. The resonator length L and inner diameter D are restricted to a range of values such that (D/L).sup.2 is less than 2.5 but greater than 1.7. To suppress the TM.sub.111 resonant modes in the resonator, two techniques are employed. A single tuning post is disposed on either resonator end plate at a point where the TM.sub.111 electric field Z-component is a maximum. The post length is adjustably fixed to maximize the output microwave power at the cavity output port. Each end plate also has a continuous gap separating each plate from the housing to suppress electric field currents of the TM.sub.111 mode flowing on the inner surface of the resonator.

Abstract: A broadband high frequency power oscillator employing a GaAs FET transistor and a two-port coupling network whose input port is connected across the drain and source terminals of the GaAs FET. The coupling network consists of 3 branches in T- or .pi.-configuration. One branch includes a matching network and the load. The other two branches are purely reactive and each includes at least one independently tunable reactance element, such as a varactor.

Abstract: A high frequency oscillator having an oscillation transistor connected to a resonant strip line unit consisting of a main strip line member and an auxiliary strip line member. The auxiliary strip line member is connected in parallel with or isolated from the main strip line member by a switch diode for switching the characteristic impedance of the strip line unit so as to generate a reception or transmission carrier wave output. A varactor diode connected to the strip line unit has its capacitance changed through an applied control voltage for channel switching. A modulating signal input terminal is directly connected to a portion of the auxiliary strip line member for modulating an FM transmission signal independently of the value of the control voltage applied to the varactor diode.

Abstract: A microwave resonance circuit device including plural microstrip lines provided on one side of a dielectric substrate. A dielectric resonator is mounted on the reverse side of the substrate from the microstrip lines and is disposed so as to have a coupling relation with a first one of the microstrip lines. A ground conductor is arranged on the reverse side of the substrate so as to overlap substantially one-half of the width of the first microstrip line extending in a direction away from the dielectric resonator, and to overlap entirely the other microstrip lines. A transistor is mounted on the same side of the substrate as the microstrip lines and connected therewith to form an oscillator circuit.

Abstract: An integrated microwave oscillator as which the generated frequency is stabilized by a dielectric resonator with high quality factor and stability. The positive feedback is assured not only by the dielectric resonator coupled to a line connected to a terminal of the active device, but also by a microstrip resonator connected in parallel to a second line connected to a second terminal of the active device. The signal generated is extracted from the third terminal of the active device.

Abstract: A switchable multi-frequency dielectric resonator oscillator that generates microwave energy at any of several available frequencies is disclosed. The oscillator includes a transistor that is operable for oscillation at a frequency determined by a feedback resonator connected to its control terminal, and switching means for selectively connecting any one of a plurality of feedback resonators to the control terminal of the transistor. The oscillation frequency of the oscillator is determined by the resonant frequency of whichever of the feedback resonators is connected to the control terminal of the transistor through the switching means. It is preferred to utilize dielectric resonators as the feedback resonators, a field effect transistor as the transistor, and PIN diodes as the switching means.

Abstract: A microwave varactor network wherein parametric oscillation modes are suppressed by coupling the varactor, with very low intervening impedence, to a bias regulator circuit (preferably an emitter follower circuit) through which the varactor bias voltage is supplied. The emitter follower is biased to always be carrying current, which improves its response time in compensating any transient bias voltage variations which appear across the varactor.

Abstract: A dielectric-resonator-stabilized, Gallium-Arsenide-FET, negative resistance oscillator operating in the microwave region incorporating an improved form of dielectric resonator whose resonant frequency is tuned by the addition or removal of metal from the surface of a dielectric tuning plate in the resonator, and a method for tuning the oscillator to the desired frequency range with the resonator in place by use of a laser-trimming device are disclosed.

Abstract: A voltage controlled oscillator of the type wherein a variable capacitance diode is connected in parallel with a distributed parameter line functioning as a resonance circuit, whose capacitance varies in response to voltage control. To vary the resonance wavelength of the distributed parameter line a condenser is connected in series therewith, and the condenser is short-circuited by a switching diode. A coaxial dielectric line, strip line, coaxial cable, etc. may be used as the resonance circuit element by dividing the distributed parameter line into two parts and employing these elements as the divided parts.

Abstract: A modulatable oscillator for radio frequencies is disclosed in which the single resonant tank includes a tightly coupled varactor diode for wideband modulation and frequency control. Nonlinearities introduced by the varactor diode are compensated by predistortion of the modulated signal yielding a predetermined modulation characteristic which is maintained over temperature.

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: A microstrip L-band bipolar dielectric resonator stabilized oscillator (DRO) devised in a moderate size (2'.times.5".times.3.6"), low-cost, reproducible circuit. Embedment of back to back varactors in the DRO provide voltage tuning for phase lock application without compromise of noise performance. Extremely low phase noise with a low l/f noise corner is achieved and the DRO is essentially constant in frequency and output power over temperature, all due to unique circuit configuration. An internal buffer amplifier and dc regulatory circuits provide a DRO that is insensitive to frequency pulling due to load changes and power supply voltage leads. New standards of performance are accomplished that permit simplified stalo configuration with lower phase noise.

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: 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 circuit is described in combination with a dielectric-resonator-stabilized oscillator operating at microwave frequencies in which a PIN diode serves to shunt the reflected output signal of the stabilizing resonator from the input of the oscillator circuit into a load to turn the oscillator off. By biasing the diode in a reverse or forward direction, the oscillator is made to start or stop oscillating, respectively. This has the effect of switching the output of the oscillator on and off while eliminating thermal transients associated with de-energizing the active element of the oscillator circuit itself, or the necessity for inefficient microwave switches which may pass some signal through.

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: 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 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: 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: In a controlled signal generator or specifically a microwave frequency signal generator, which requires a quieting capacitor, improved switching speed without degrading noise performance is provided by switching out the quieting capacitor during frequency changes, precharging it to the new condition, and then reconnecting it for normal operation. Other error causing current drains are also compensated for.

Abstract: A power oscillator for transmitter equipment operating at hyperfrequencies such as microwave links and radar. A plurality of elementary oscillators are coupled in parallel. Each elementary oscillator comprises a field effect transistor (FET) (11) connected in the common drain configuration with a first microstrip (51) connected to its gate and a second (21) connected to its source. Adjacent gates are interconnected by first resistances (R1) and adjacent sources by second resistances (R2). The resistances serve to balance the oscillators and to suppress parasitic oscillation. The free ends of the gate microstrips (21) are interconnected to synchronize the oscillators and the free ends of the source microstrips (51) are interconnected to constitute the oscillator outlet. The FETs may be disposed in a line or in a ring.

Abstract: A push-pull microwave oscillator circuit, including two transistors, for producing the second harmonic of a fundamental frequency at a symmetry point of the circuit which is connected to the bases of the transistors through identical arrangements of circuit elements. The circuit includes tuning means coupled to at least one of the transistors, an output and an input. The output, which is utilized to provide to a phase comparison means an output signal at the fundamental of the second harmonic frequency, is coupled to the base of at least one of the transistors by a capacitive impedance. The input, which is utilized to receive a tuning signal produced by the phase comparison means in response to the output signal, is coupled to the tuning means.

Abstract: A microwave oscillator and a combination microwave oscillator/single balanced mixer for a satellite television receiver includes a cylindrical dielectric resonator located on one side of a ground plane formed by a conductive foil on a substrate with microstrip transmission lines formed by foil patterns on the opposite side of said substrate. A gallium arsenide FET is disposed in a hole through said substrate with its source electrode connected to the ground plane and its drain and gate electrodes coupled to first and second transmission line strips, portions of which are following the contours of said dielectric resonator. Two sets of coupling slots are formed in the ground plane for permitting magnetic coupling between the dielectric resonator and the opposite transmission line strips. In one embodiment an additional coupling slot in the ground plane couples the dielectric resonator to an output transmission line strip.

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: A microwave transistor oscillator/doubler comprising a Field-Effect Transistor with Terminals G, D and S in combination with a coupling network connected to the terminals G, D and S and composed of microstrip lines with lengths equal to a quarter wavelength at the second harmonic of a fundamental frequency. The doubler further comprises a bias circuit for supplying appropriate voltages to the FET terminals, and an impedance coupler for coupling from the FET D-S terminals to a waveguide load. The coupling network optimizes feedback at the second harmonic between the D-S and G-S ports of the FET to prevent destructive harmonic feedback interaction with the desired signal while providing optimum conditions for feedback at the fundamental frequency. The bias circuit is connected to the coupling network and includes a second network of transmission line elements of lengths equal to a quarter wavelength at the fundamental in order to prevent dissipation of the fundamental frequency therein.

Abstract: An IMPATT diode oscillator wherein the diode is coupled to a first transmission line in turn coupled to a bias port at one end and to a coupled line transformer formed with a second transmission line at the other. A stabilizing load is coupled to the first transmission line between the diode and the bias port. A first tunable resonator controlling the fundamental frequency of the oscillator and a second tunable resonator controlling the second harmonic frequency of the oscillator are coupled to the first transmission line between the diode and the stabilizing load so that independent control of the fundamental and the second harmonic is attained in a temperature stable device.

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 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: 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 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: A microwave oscillator circuit with an FET, a dielectric resonator and a micro-strip line has a capacitive reactance element connected between the source terminal of the FET and ground or between the source and drain terminals of the FET, so that the oscillation frequency fluctuations due to the power supply voltage fluctuations or the ambient temperature variations can be suppressed.