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 high frequency pulse-time modulation (PTM) signal generator employs four or more high frequency oscillators which are mutually locked uniquely either in a symmetric mode or an antisymmetric mode by means of a plurality of electronic phase shifters. The output signals from the oscillators are cascaded together to form a PTM output through control of the electronic phase shifters which shift the mutual locking of the oscillators back and forth between the symmetric and antisymmetric modes. Magic-tees or other combining elements are employed to combine the oscillator output signals so that an output pulse is generated when the oscillators are locked in the symmetric mode and a zero level output is generated when the oscillators are locked in the antisymmetric mode.

Abstract: A high-power oscillator which uses a quasi-optical ring resonator to prov the feedback required for oscillation allows energy to travel in one direction only within the resonator and suffers little loss of energy during operation. The oscillator is built by inserting an array of amplifiers, tuned to a desired frequency, into the quasi-optical ring resonator formed by three reflective mirrors. The mirrors are spaced such that the total loop phase shift is equal to an integer multiple of 360 degrees at the desired frequency and, by proper selection of the amplifiers, the loop gain is set to be greater than or equal to one.

Abstract: An injection-locked variable-frequency high-power microwave frequency generator includes an injection source, a circulator, and an oscillator. The circulator includes an injection port to the injection source, an oscillator port to the oscillator, and a transmission port. The circulator directs the injection signal from the injection source into the oscillator and directs the oscillator output out the transmission port. The oscillator includes an IMPATT diode and a microstrip matching circuit. The matching circuit provides the sufficient conditions for broadband (9.1-9.5 GHz) oscillation of the diode. To this end, the matching circuit provides three resonators having three different but closely coupled resonant frequencies. The matching circuit also serves as a transformer, providing impedance matching to the circulator. A high-power output can be chirped or otherwise controlled by electronic control of the injection frequency.

Abstract: An array of unit oscillators interconnected with one another in that the transistors of the oscillators are connected to common lines. Separate lines in proximity provide coupling capacitance for feedback to sustain the oscillation of the unit oscillators. The separate lines also form a grid which results in an antenna for emanation of the oscillators, radiation The array can effectively function at extremely high frequencies (i.e., greater than 30 GHz). The array is specially designed to accommodate monolithic implementation.

Abstract: A microwave power combiner includes a first plate having disposed in a first surface thereof a first plurality of grooves and a second plate having disposed in a first surface of said second plate a second plurality of grooves, with said second plate being mated to said first plate and with said first plurality of grooves in the first plate disposed in alignment with the second plurality of grooves in the second plate to provide a plurality of waveguide regions. The waveguide regions are further disposed to provide a plurality of hybrid Ts preferably matched hybrid Ts or magic Ts which are selectively interconnected to form an integrated combiner structure. A first surface of the plate is used to mount a plurality of IMPATT diode modules whereas the second opposite surface of the composite plate is used to mount a heat sink thereby providing a thermal path between the diode modules through the composite plates to the heat sink.

Abstract: A microwave oscillator/power combiner incorporates two microstrip transmission lines, each coupled electromagnetically to an output transmission line. Each of the microstrip transmission lines incorporate active diodes such as IMPATT or GUNN diodes which generate RF energy when acted upon by a DC voltage. The output transmission line is coupled to ground to allow the output end of the transmission line to be adjacent to the active diodes. The two microstrip transmission lines are coupled to a high Q tank circuit through a Wilkinson power divider. The high Q tank circuit is preferably a dielectric resonator. The oscillator may be cascaded to increase power output.

Abstract: Disclosed is a circuit for power combining electromagnetic energy in the millimicrowave frequency band where the electromagnetic energy is produced by two substantially identical varactor tuned microstrip oscillators where the power combining circuit has less than perfect isolation properties allowing a fraction of the output of one to be fed back to the other so that the two become locked in frequency.

Abstract: A plurality of millimeter wave power sources are arranged in a planar mat array located in a wave-beam resonator including two reflecting surfaces which are large in terms of the operating wavelength. One surface comprises a planar reflector located in relatively close proximity to the source array, while the other reflector is located in front of the array at a relatively larger distance and being partially transparent and curved, with the curvature being expressed by a pair of focal lengths which define a curvature in two perpendicular axial planes. Each source is comprised of an IMPATT or GUNN diode coupled to a short dipole or closed current loop structure, all lying in a plane parallel to the planar reflector and transverse to the longitudinal central axis of the resonator.

Abstract: A composite diode module is provided having an impedance matching member integrally formed within the module. The module includes a base member, a heat sink holder member having an aperture, a gold plated diamond heat sink which is disposed in the aforementioned aperture, and an encapsulant holder member having a second aperture. IMPATT diodes are disposed in dielectric spacers bonded to one end of the heat sink in alignment with the second aperture. A bias pin member is then bonded on the second end of the IMPATT and an encapsulant having selected electrical properties is provided in the second pair of apertures to secure the diode and to provide the diode module with a predetermined impedance characteristic. In a preferred embodiment, the module includes a pair of IMPATT diodes. With this arrangement, the module may be used in power combiners.

Abstract: A method and arrangement for enhancing the level of supplied microwave energy including a resonant ring capacitively coupled to a microwave coupling device effective for connecting to a microwave transmission line, the arrangement being mounted in a shield structure. Amplification is effected by IMPATT diodes capacitively coupled to the resonant ring. The microwave coupling device is variably setable with respect to the transfer structure, thereby promoting the establishment of impedance matching therebetween.

Abstract: An injection-locked waveguide oscillator comprises a first diode (3) having a free-running fundamental frequency above the local cut-off frequency of the waveguide (1) and a second diode (4) having a fundamental frequency below and a higher harmonic above the local cut-off frequency. The first diode (3) may be an IMPATT diode and the second diode (4) a Gunn diode. The free-running fundamental frequency of the first diode (3) is close to the higher harmonic of the second diode (4) so that the second diode (4) injection-locks the first (3). Locking in the reverse sense is inhibited by the inherent loss in conversion from the higher harmonic to the fundamental in the second diode (4), thus avoiding the need for a circulator or isolator. The two diodes (3, 4) preferably are mounted in a common waveguide (1) for a simple compact structure.

Abstract: A metallic support supports a number of semi-conductor devices surrounded by an annular dielectric substrate which in turn supports a circuit including at least two microstrip lines and a metallic circular output element. The small thickness and high dielectric constant of the substrate are selected to permit a reduction in width and in length of the microstrip lines which are folded-back in a curvelinear fashion and placed on the substrate along circular arcs which are concentric with the output element.

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: 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 plurality of negative resistance devices is spaced below a cylindrical center conductor of a single coaxial cavity. Each negative resistance device has a bias device connected to it by a bias wire. Extending radially through the outer wall of the coaxial cavity is a coax cable with an RF coupling probe. A tuning screw is place axially through the interior of the center conductor for tuning the frequency of the power combiner.

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 radio frequency numerically controlled oscillator comprising N one bit adders each providing sum and carry outputs to one of N two bit registers. Sum, carry and frequency selection inputs are combined by each adder to form sum and carry outputs. These results are held by the associated register when triggered by a clock input. A fast parallel adder/latch is employed which has two stages connected serially to generate sums on opposite phases of a two phase clock.

Abstract: A mm wavelength power combiner comprising an open resonator comprising a r of confronting concave reflectors which can be either spherical or parabolic. The resonator dimensions are many times the wavelength of the energy sources to be combined. A plurality of mm wave energy sources are applied to the resonator in such a way that the great majority of the energy bounces back and forth between the reflectors near the axis thereof in the fundamental or Gaussian mode. The design minimizes multimoding and diffraction losses.

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: At least two oscillators (20) are power combined using planar transmission lines, e.g., microstrip, stripline, or suspended substrate. A portion (42) of each oscillator (20) is preferably implemented in suspended substrate while an impedance matching portion (24) is preferably implemented in microstrip. Each oscillator (20) comprises a two-terminal negative-resistance active device power source (22) such as a negative resistance diode. The sources (22) are all operated in phase in the even mode. Stabilizing resistors (8) connect adjacent oscillators (20) to keep the sources (22) in phase. A diplexer (29, 33) within each oscillator (20) isolates the RF output (and RF input when injection locking is employed) from the individual DC biases used for sources (22), controls out-of-band impedances, and isolates oscillators (20) from each other. The outputs of the oscillators (20) are summed at a common junction (12) via planar transmission line spokes (10) having equal lengths.

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 combiner for power combining electromagnetic energy is disclosed. At least two electromagnetic cavities are positioned having intercavity coupling among all cavities: each cavity is tangent to all other cavities and/or external transmission line connections are employed to enhance/provide intercavity coupling. Each cavity contains within it at least one power generating device. An input/output port is connected via a nonreciprocal device to an output load and an injecting oscillator which usually has a lower power level than that of the free-running combiner and a higher spectral purity. The cavities are intentionally tuned to at least two different frequencies. For the two cavity and three cavity embodiments, a greater bandwidth is obtained compared with prior art combiners where the cavities are tuned to the same frequency. The power loss is slight.

Abstract: An efficient higher order mode resonant combiner in which a higher order mode accumulator cavity is adjusted to have the real part of its input characteristic impedance to be so minimized as to be less than the characteristic impedance Z.sub.o of the input circuit. When an active device is matched to this low, minimized value of cavity input impedance a mismatch results between the active device power source and the input to the combiner at undesired higher order modal frequencies. This resultant mismatch at undesired modal resonances obviates the need for mode suppression devices within the cavity which devices as taught in the prior art had detrimental effect of the efficiency of the combiner.

Abstract: A solid state microwave source placed within a rectangular waveguide, whose one end is short-circuited. The microwave source incorporates a negative resistance diode system placed on the inner wider wall of the waveguide and perpendicularly with respect to the waveguide transmission direction, a resonant microband line suspended by means of a dielectric substrate, a connecting means between the diode system and the resonant line, and means for connecting to an external polarization source.

Abstract: In a microstrip circuit having dual diode driven, independently oscillati half-wave open ring resonating sections, partially coupled quarter-wave ring sections are provided to permit matching and tuning of diodes having dissimilar negative impedances. The quarter wave ring sections are combined with appropriate line sections to accommodate the negative impedance devices. The diode circuits are connected to the low impedance points of the oscillating ring sections by the quarter-wave ring sections. Appropriate terminations to ground are provided to suppress possible oscillations in a bias circuit. Second and third harmonic traps are provided for use with TRAPATT diodes. Ground lines are provided to reduce circuit unbalance in the event of drastic power changes occuring on either side of the circuit which may other wise result in odd mode operation. Slots are provided to suppress an undesired transverse resonance mode in the line sections accommodating the negative impedance devices.

Abstract: A microwave oscillator/amplifier includes a plurality of TEM transmission lines each with a negative resistance device at one end and a lossy, matched termination at the other end. A resonant cavity is coupled to each TEM line so as to induce a parallel resonance on the lines at the region of coupling. Structural means are provided for maintaining the characteristic impedance of the TEM lines uniform along the length of said lines. Fabrication of a device in which the TEM line characteristic impedance was uniformly maintained along the line length at five times the optimum negative resistance of said negative resistance device is noted. Suggested levels of characteristic impedance are relatively low compared to prior art devices, none of which are known to attempt maintenance of characteristic impedance uniform along the length of the TEM transmission line.

Abstract: A circuit capable of providing the negative resistance heart of oscillators or amplifiers in the 5-20 Gc/s frequency band, comprising a central resonant cavity and one or several peripheral exciting chambers, each containing a push-pull arrangement of two diodes for example three pairs of diodes in chambers arranged at 120.degree. from one another on a circle concentric to the central cavity. The diodes are located at the bottoms of cylindrical exciting chambers communicating with the central chamber through holes situated at the center of each push-pull arrangement. Each pair of diodes is maintained and polarized by a metallic bar which plays, with the walls of the exciting chamber, the role of an impedance transformer between the diodes and the central cavity. The metallic bar is maintained by a polarization rod penetrating the chamber through an insulating passage.

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: A microstrip circuit which features a pair of open ring resonators sections adapted to oscillate independently in their even mode. In a preferred form, the ring resonator sections are each driven by a TRAPATT diode, and include a load circuit which combines the individual power outputs to a common load. Tuning stubs and the like may be provided to reactively trap harmonics in order to initiate the desired TRAPATT mode, and additional ring resonators may be interposed between the driving circuit and the load to filter the fundamental frequency, if desired. Other configurations permit power to be combined from two or more sets of dual ring resonators.

Abstract: A high peak power microwave generator is disclosed in which a plurality of transmission lines are connected to an output wave guide at predetermined intervals along the direction of propagation. Each transmission line is periodically charged, and this electromagnetic energy is released into the wave guide upon the actuation of a light activated silicon switch (LASS) diode connected to the transmission line. The LASS diodes are actuated simultaneously by a laser beam which traverses equal optical paths to each switch. The coincident switching of the transmission lines enables the power in each line to be additive in the wave guide, and much higher output pulses can be obtained. Further, the high speed switching capabilities afforded by the LASS diodes means that the resulting high power can be obtained at a much higher frequency.

Abstract: A modular microwave power combiner having a plurality of identical microwave diode amplifier circuits grouped in sets within the body of a modular unit which are electrically coupled in parallel to a central cavity sized to be resonant at a single frequency to minimize mismoding thereby enhancing combiner efficiency. A number of waveguides are provided for coupling of the microwave diode in each amplifier circuit to the resonant cavity, and the waveguides are situated on one side of a PC board at the top of each modular unit. Since each of the modular units is essentially identical in physical size and shape, the overall power output of the power combiner can be increased by merely adding additional modular units. The individual modular units are sized to fit top-to-bottom such that the respective resonant cavities are spaced apart by one-half wavelength (.lambda./2) for the parallel electrical coupling of all of the resonating cavities.

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.