Abstract: A linear-circular polarizer used for the transmission in the microwave band, which provides excellent impedance characteristics and stabilized cross polarization characteristics by having 1/4 wavelength phase plates and the inner surface of a circular waveguide made in one-piece for the purpose of cost and production step reduction. The linear-circular polarizer includes a pair of 1/4 wavelength phase plates of a specified width and height formed opposite to each other and symmetric with respect to the waveguides central axis. The 1/4 wavelength phase plates are formed on the inner surface of a circular waveguide at a closed end opposite to an end where a primary radiator is located.

Abstract: A UHF phase shifter including a UHF waveguide having an electrooptical element lying between two elements 3 and 4 made of materials which have permittivity higher than that of the electrooptical element. An electric polarization field is applied for controlling the electrooptical element and a UHF line is inserted into the element. The control of the orientation of the molecules of the electrooptical element allows for a variation of the index of the element as seen by the field of a UHF wave.

Abstract: A circular-linear polarizer includes a waveguide and a one quarter wave length plate which is installed on the inside wall of the waveguide. The surfaces of the waveguide and the one-quarter wave length plate forming the junction between them are flat. Alternatively, the one quarter wave length plate has a mounting surface for mounting on the inside wall of the waveguide. The mounting surface has a circular cross section which is complementary to the circular inside cross section of the waveguide. The junction provides improved electrical contact between the waveguide and the one-quarter wavelength plate. In addition, the cross polarization and axial ratio of the waveguide are improved while maintaining good impedance characteristics.

Abstract: A linear-circular polarizer used for the transmission in the microwave band, which provides excellent impedance characteristics and stabilized cross polarization characteristics by having 1/4 wavelength phase plates and the inner surface of a circular waveguide made in one-piece for the purpose of cost and production step reduction. The linear-circular polarizer includes a pair of 1/4 wavelength phase plates of a specified width and height formed opposite to each other and symmetric with respect to the waveguides central axis. The 1/4 wavelength phase plates are formed on the inner surface of a circular waveguide at a closed end opposite to an end where a primary radiator is located.

Abstract: A phase shifter employing a voltage variable dielectric material to add controlled phase delay in a ridged-waveguide section. The dielectric material has the property that its dielectric constant varies with changing electric field applied to the material. The dielectric material fills the ridge gap between the two waveguide ridges. An electrode is disposed within the dielectric material, and is connected to a variable voltage source to establish a transverse electrical field within the dielectric material. By varying the voltage, the magnitude of the field is varied, thereby allowing the phase delay of electromagnetic signals propagating through the waveguide section to be changed.

Abstract: A microwave switch selectively directs a microwave signal along first and second signal paths. The switch includes a microwave transmission member, a microwave chamber formed by the transmission member for containing an ionizable gas, input and output ports formed by the transmission member to communicate with the microwave chamber and a triggered plasma generator which is configured to generate, in response to a voltage trigger signal, a trigger electron density N.sub.t in the gas. The microwave signal increases the trigger electron density N.sub.t to a reflective electron density N.sub.r. Consequently, the microwave signal is reflected along a first path from the input port when the trigger electron density N.sub.t is present and is directed along a second path to the output port when the trigger electron density N.sub.t is absent. A plurality of these microwave switches is arranged to form a tunable microwave short.

Abstract: A system for synthesizing a microwave filter including a plurality of resonators having no tuning elements, in particular waveguide filters for use in satellite telecommunications networks. Signals representing the coupling coefficients of the coupling elements having a finite thickness and the resonant frequency of the resonators are stored in an electronic memory. A computation unit is controlled by a control unit arranged to determine automatically, in a single run, the widths of the coupling elements and the lengths of the resonators from the signals representing the coupling coefficients.

Abstract: A photographic lighting system for use with a camera provides fill light from the direction of the camera to alleviate shadows in a photographic image obtained by the camera. The photographic lighting system includes an incident light sensor for sensing the incident light intensity on a subject to be photographed, an electric light for directing fill light toward the subject, and a control circuit for controlling the intensity of the fill light provided by the electric light in response to the sensed incident light intensity. The fill light is increased in intensity as the incident light intensity increases. The control circuit can also receive a distance input representative of the distance between the electric light and the subject and controls the fill light in response to the distance input such that the fill light intensity at the subject is substantially independent of the distance.

Abstract: A phased array antenna includes an array of phase shifters, each shifter being operable for shifting the phase of RF energy passing therethrough. Each shifter includes a quantity of ferroelectric material disposed throughout a region. RF energy propagating from a source passes through the material. A thin conductive electrode is disposed in the center of the material, the electrode having a bias voltage imposed thereon. Such voltage creates an electric field across the material, which for a uniaxial ferroelectric orients the optic axis of the material in a direction which is both normal to the direction of propagation of the RF energy and parallel to the polarization direction of the RF energy. The electric field changes the wave propagation constant (i.e., for a uniaxial ferroelectric, the extraordinary wave refractive index, n.sub.e), producing a varying path length of the RF energy in the material, resulting in a controllable alteration of the phase of the RF energy.

Abstract: In a reciprocal microwave phase shifter of microstrip technology, a Ferrite substrate carries, on one side, a ground plane (PM) and, on the other, a microstrip line (LM). The lateral branches (CG2 and CD2) cooperating with a base (CC) to define a magnetic circuit come into direct contact with the Ferrite substrate (SF), be being, for example, equipped with a recess (ED2) in line with the passage of the microstrip line (LM).

Abstract: In a microwave plasma generating method and apparatus according to the present invention, a slow wave structure is disposed in the propagation region of microwaves, and the microwaves are introduced at a delayed phase velocity into a discharge chamber so that treating gases are transformed into plasma. Thus, the phase velocity of the microwaves is adjusted to a relatively low velocity, at which charged particles are distributed most densely in the plasma, so that the energy may be efficiently transformed to many more charged particles in the plasma. Thus, the plasma of high density is generated to improve a plasma treating rate.

Abstract: A digitally controlled distributed phase shifter is comprised of N phase shifters. Digital control is achieved by using N binary length-weighted electrodes located on the top surface of a waveguide. A control terminal is attached to each electrode thereby allowing the application of a control signal. The control signal is either one or two discrete bias voltages. The application of the discrete bias voltages changes the modal index of a portion of the waveguide that corresponds to a length of the electrode to which the bias voltage is applied, thereby causing the phase to change through the underlying portion of the waveguide. The digitally controlled distributed phase shift network has a total phase shift comprised of the sum of the individual phase shifters.

Abstract: A system for coupling energy between electrical and mechanical waves includes a mechanical waveguide for propagating a mechanical wave having a mechanical wavelength at a given frequency, and an electromechanical energy converter for coupling energy between electrical and mechanical waves attached to a portion of the waveguide and capable of propagating an electrical wave having an electrical wavelength substantially equal to the mechanical wavelength at the given frequency. The portion has a length, measured in units of coupled wavelength, which is selected on the basis of the reciprocal of the coupling strength of the electromechanical converter and a selected amount of wave energy to be coupled. The function is based primarily on desired efficiency and may also be an odd integer multiple of the coupling strength reciprocal, preferably one. Piezoelectric elements are the preferred electromechanical energy conversion elements.

Abstract: A phase shifter for use in a phased array antenna includes a waveguide flange of metallic material has a narrow slot formed therein, the slot having ferroelectric material disposed uniformly therein. The slot is of reduced height relative to normal waveguide dimension, such height reduction minimizing the voltage applied across the material RF energy radiating from a source is directed to pass through the ferroelectric material. A single, thin conductive plate is disposed in the center of the slot, the plate having an electrical DC voltage imposed thereon. Such voltage creates an electric field across the material, which for a uniaxial ferroelectric orients the optic axis in a direction which is both normal to the direction of propagation of the radiation and parallel to the polarization direction of the radiation. The electric field changes the wave propagation constant (i.e., for a uniaxial ferroelectric, the extraordinary wave refractive index, n.sub.

Abstract: A liquid crystal is used as the phase modulating medium in a microwave phase modulating cell (20). Applied electric and/or magnetic fields transverse to the direction of wave propagation create a birefringence that changes the velocity of wave propagation and the index of refraction of the medium. The phase modulating cell (20) is used singly or in arrays to direct microwave beams.

Abstract: A phased array waveguide antenna having a plurality of longitudinally extending parallel waveguides arranged in rows and columns, and electrically controlled phase shifter strips disposed in longitudinally extending slots centrally located in respective columns of waveguides. The electrically controlled phase shifter strips include conductive patches that are selectively conductively connected together by microwave diodes to provide for variable susceptances.

Abstract: A waveguide having walls defining an opening. An optically transmissive aperture in one wall allows light from an optical illumination source such as a laser diode array to illuminate the opening in which is located a semiconductor slab positioned to be illuminated. When the array illuminates the slab, the propagation characteristics (phase velocity and attenuation constant) of the waveguide changes. A continuous wave signal passing through the waveguide is thus attenuated and phase shifted. The laser array may be pulsed on and off while still maintaining the altered propagation constant.

Abstract: An element with periodic structure for guiding electromagnetic waves propagating along a longitudinal axis of the structure at a speed below the velocity of light is disclosed. The structure includes a series of metal polar expansions aligned with the mentioned axis and forming a plurality of resonant metal cavities. The polar expansions have respective apertures aligned with each other so as to form a freeway for electron flow. First and second conductors are provided for cooperating with the polar expansions. The polar expansions each further respectively have first and second apertures for receiving first and second conductors that are preferably positioned diametrically opposed to each other with respect to the mentioned longitudinal axis.

Abstract: A computer aided design (CAD) method for designing circular overmoded waveguide systems having optimal operating characteristics. The CAD method receives selected input waveguide operational, material and structural parameters and computes the resulting waveguide operational characteristics, including power losses for a given waveguide system configuration, including both straight and bent sections. Optimal designs for lined dielectric and sheathed-helix types of circular waveguide and waveguide bends have resulted for both S- and X-band operation.

Abstract: An electromagnetic dispersive delay line (10) includes a dielectric strip (28) as well as a coupler (24, 34, 36, and 38) for launching surface electromagnetic waves into the dielectric strip. The upper surface of the dielectric strip (28) is left exposed to the air in order to provide an interface with a lower-permittivity medium of propagation. This permits a surface-electromagnetic-wave propagation mode. The thickness of the dielectric strip (28) is varied along its length so as to result in a linear relationship of delay to frequency throughout a predetermined frequency range. Preferably, a conductive strip (26) spaced from the dielectric strip extends along the surface-wave propagation path in the region occupied by the evanescent field external to the dielectric strip (28). This conductive strip (26) modifies the phase relationships between the electric and magnetic fields in the evanescent-field region so as to cause some of the power transmission to occur outside of the dielectric strip.

Abstract: The coaxial-waveguide phase shifter consists of a coaxial waveguide section, comprising an external cylindrical conductor and an internal cylindrical conductor, both hollow. Between them a number of irises are provided parallel to one another. The irises can be differently shaped and can be fixed to the external or to the internal conductor. By replacing the internal cylindrical conductor with a rectangular conductor, the irises can be unnecessary.

Abstract: A monolithic microwave integrated circuit (MMIC) phase shifter is implemented in push-pull configuration with the quadrant selection and vector modulation functions combined. These functions are provided by four sets of adjustable gate-width dual-gate FETs and a pair of lumped element filter networks with a relative differential phase shift of 90.degree..

Abstract: A microwave transmission line is provided including a class of dielectric terials known as relaxor dielectrics having very high dielectric constants of greater than 1000, low dielectric loss and large variations of the real part of the dielectric constant with varying temperature. The phase of a microwave signal passed through such a transmission line is modulated by subjecting the transmission line to light that is absorbed in the dielectric layer causing a variation in the dielectric constant and a change in the velocity of the continuous microwave signal passing through the transmission line.

Abstract: A polarizer has a plurality of short waveguide sections arranged so that rectangular-shaped sections alternate with circular-shaped sections. The two end sections are both circular. The rectangular sections have a minimum size at least as large as the minimum diameter of the circular sections. The size of the rectangular sections progressively changes from section to section with all sections of the polarizer being symmetrical about the centre point of the polarizer. The length of each section is less than half a wavelength at maximum operating frequency. The structure of the polarizer is simple and straightforward so that computer-aided analysis and design methods can easily be used. The polarizer has a relatively large bandwidth and can interface directly with corrugated circular waveguides.

Abstract: The invention comprises a Schottky barrier type infrared photodetector which is monolithically integrated on a silicon waveguide. A Schottky barrier contact is positioned directly on a silicon waveguide to absorb grazing incidence optical signals passing through the waveguide. The Schottky contact is operated in the avalanche or reverse bias mode to generate a useable electrical signal.

Abstract: A compact, dual series waveguide feed network is disclosed which has application to monopulse radar antennas and is usable in applications requiring compact and light weight feed networks. The network in accordance with the invention uses phase shifters at the phase reversal points of the secondary (42) feed lines to establish a 180.degree. relative phase difference with the corresponding phase reversal point of the primary feed line. No phase shifters are used in the crossguide feed lines (44). Because of the invention's phase shifter arrangement, crossguide lines (44) may be located directly opposite each other instead of being staggered as in prior techniques; hence the size of the network is reduced and resolution is increased. Also, the primary and secondary feed lines may be located closer together because there are no phase shifters with associated matching and transition devices located in the crossguide feed lines.

Abstract: An electromagnetic dispersive delay line (10) includes a dielectric strip (28) as well as a coupler (24, 34, 36, and 38) for launching surface electromagnetic waves into the dielectric strip. The upper surface of the dielectric strip (28) is left exposed to the air in order to provide an interface with a lower-permittivity medium of propagation. This permits a surface-electromagnetic-wave propagation mode. The thickness of the dielectric strip (28) is varied along its length so as to result in a linear relationship of delay to frequency throughout a predetermined frequency range. Preferably, a conductive strip (26) spaced from the dielectric strip extends along the surface-wave propagation path in the region occupied by the evanescent field external to the dielectric strip (28). This conductive strip (26) modifies the phase relationships between the electric and magnetic fields in the evanescent-field region so as to cause some of the power transmission to occur outside of the dielectric strip.

Abstract: A delay line is provided for effecting a desired delay in the transmission of electromagnetic waves in the microwave and millimeter range of the spectrum. The line comprises a length L of a dielectric waveguide for transmission of electromagnetic waves comprising a core of polytetrafluoroethylene having one or more layers of polytetrafluoroethylene overwrapped around the core, wherein T=KL/c, in which T is the total time delay , c is the velocity of light in free space and K is the delay constant of the dielectric waveguide. Preferably, the delay line is overwrapped around a mandrel.

Abstract: A microwave polarizer is provided in the form of a wedge at the termination of a rod of dielectric material. Preferably the wedge tapers exponentially in order to provide a good impedance match. Circularly polarized radiation propagating along the rod experiences a differential phase shift at the wedge. This phase shift may be arranged to be 90.degree., so that linearly polarized radiation exits from the wedge. A continuous circular or square guide is used to contain the dielectric rod so that simultaneous orthogonal signals can be converted to or from circular polarizations. Such a wedge termination may be provided at the end of a splashplate or polyrod antenna feed, for a satellite communication system, where right-handed circular polarization is used on the up-link and left-handed circular polarization is used on the down link.

Abstract: A correlator apparatus that simultaneously delays two time-varying input signals using just a single transmission line, with the signals being connected to opposite ends of the line. Directional couplers spaced along the transmission line extract delayed versions of the two input signals, for correlation by a bank of correlators, to produce a correlation envelope for the two signals. The apparatus is substantially less massive than prior apparatus of this kind and can be easily constructed and aligned.

Abstract: A microwave phase shifter comprise a dielectric waveguide having a flat side and a moving conductor plane member substantially parallel to the waveguide side. Piezoelectric means are provided to move the plane member with respect to the waveguide side between a portion relatively remote from the waveguide side and an other position substantially in contact with the waveguide side. The piezoelectric means consists preferably of a stack of piezoelectric members supplied by a variable d.c. power source. Owing to the piezoelectric means for moving the conductor plane member, a variable phase shift is continuously adjusted. Such a phase shifter can be as an antenna network when the dielectric waveguide contains groups of radiator perturbations, such as conductor strips, respectively controlled by one or several piezoelectric means carrying conductor plates facing waveguide portions including the perturbations groups.

Abstract: A differential phase shifting structure is disclosed, employing corrugated ridges in square or round waveguides or in coaxial lines operating in the TE.sub.11 mode. The structure provides a substantially constant differential phase shift between two waves polarized orthoganally to each other. The corrugations in the ridge provide a series inductance which can be optimized with the shunt capacitance of the ridge to provide a characteristic impedance matching that of the unloaded structure. The corrugated ridges provide increased differential phase shift per unit length. The differential phase shifting structure is particularly well suited to such applications as circular polarizers, quarter wave plates or polarization rotating half-wave plates.

Abstract: A phase compensated waveguide hybrid coupler is formed with a pair of waveguides of rectangular cross section and sharing a common short wall. An aperture in the short wall provides for the coupling of electromagnetic energy between a first of the waveguides and a second of the waveguides. Such coupling introduces a 90.degree. phase shift. An input terminal is located at an end of the first waveguide. Phase compensation is introduced by a set of capacitive irises located in the first waveguide and by a set of inductive irises located in the second waveguide. The capacitive and inductive irises are located on a side of said coupling aperture away from said input terminal.

Abstract: A dual band circular polarizer for simultaneously transforming two to four linearly polarized waves of two different frequency bands into two to four circularly polarized waves, and vice versa, the polarizer comprising a waveguide of circular or square cross-sectional shape dimensioned to simultaneously propagate signals in two different frequency bands and two arrays of conductive elements, each array comprising a pair of diametrically opposed rows of conductive elements extending inwardly from the walls of the waveguide.

Abstract: A phase shifter for microwave electromagnetic energy propagating through a waveguide has a composite structure of a series of capacitive phase shifting posts positioned within the waveguide diametrically across from a symmetrically tapered ridge. The series of posts introduce a nominal value of phase shift with an incremental value which increases with increasing frequency of the electromagnetic energy. The tapered ridge introduces a nominal value of phase shift plus an incremental value which decreases with increasing frequency of the electromagnetic energy. The rates of increase and decrease of the incremental values of phase shift cancel so as to provide a resultant phase shift which is substantially invariant with frequency.

Abstract: A microwave phase shifting device utilizing the rotation lateral to a longitudinal axis across a square or circular waveguide by a slab of dielectric material to provide a differential phase shift between a linear to circular polarization in a high frequency microwave signal.

Abstract: A reflection phase shifter connectable to a waveguide for shifting the phase of a high frequency signal received from the waveguide. The phase shifter includes a waveguide section having two pairs of opposite side walls and an end wall forming a short-circuit. The side walls define a cavity and an opening opposite to the end wall for communication with the waveguide. The waveguide section has a broad dimension between one pair of opposite side walls corresponding to the width dimension of the waveguide and a narrow dimension between the other pair of opposite side walls which is smaller than the height dimension of the waveguide. A switchable semiconductor arrangement, including a switching semiconductor element and a housing for accommodating the switching semiconductor element, is adjustably mounted in a side wall of the waveguide section and penetrates into the said cavity with a controllable penetration depth for tuning said waveguide section for a desired phase angle shift.

Abstract: Differential phase-shifter operating in a wide frequency band, with constant differential phase shifting. This device is characterized by the fact that it produces a differential phase shift between two perpendicular polarizations, with constant frequency. This way, differential phase shifters with the desired flatness in the band can be obtained, either of 180.degree. (polarizers for systems of linear polarization) or of 90.degree. (polarizer for transforming the circular polarization into linear polarization and vice versa). Such a phase shifter can be used generally in antenna systems.

Abstract: To ensure stability of tubes comprising a delay line of the ceiling and ring type or of the ceiling and bar type, resonating slits are disposed in the ceilings of the line.

Abstract: A double-coupled ladder circuit for a traveling-wave tube has been a slow-wave circuit formed of a pair of combs, each cut from a single piece of metal. Transverse grooves are cut in each piece to form teeth and axial grooves are cut in the ends of the teeth. The two combs are joined at teeth ends to form a ladder with the transverse grooves aligned to form cavities and the axial grooves aligned to form a beam passageway. Coupling apertures are cut in both sides of a first set of alternating ladder rungs and a second set of apertures cut in the comb backing members over the second, interleaved, set of rungs. Thus, each cavity is coupled on two opposite sides to its preceding cavity and on the two remaining sides to its following cavity. The double coupling provides increased bandwidth and efficiency. Finally, side plates are affixed to cover the apertures, complete the cavity walls and form the vacuum envelope.

Abstract: A microwave phase shifter for use in waveguide transmission line employs a piezoelectric cantilevered bimorph member mounted on the waveguide and a thin wafer of dielectric material mounted on the free end of the cantilever above a slot in the waveguide. Voltages applied to the bimorph member cause this member to distort so as to insert the wafer into the waveguide slot and alter the phase of the microwave signal being transmitted.

Abstract: An apparatus for changing the phase of a microwave signal comprising:a sample that exhibits the magneto-electric effect;a metal enclosure loaded with said sample; a voltage source; a feed electrode and a ground electrode attached to said sample and to said voltage source so that a voltage difference is created across said sample by said voltage source, said feed electrode connecting said voltage source and said sample by passing through said; a coupling slot in said enclosure that enables microwaves to enter into said enclosure and leave said enclosure after the microwave has been phase shifted and a means for producing a magnetic field inside the metal enclosure.

Abstract: A millimeter wave reflection phase shifter employs a fin-line structure within a waveguide network which has a central leg and four arms which together form two symmetric Y-junctions. The fin-line forms a septum within the waveguide and includes a conductive layer having a central gap or slot therein which extends along the leg and into each of the arms. Means for shorting the slot arms disposed at one end of the leg controls the phase shift experienced by a signal propagating through the phase shifter. This phase shifter may provide multiple selectable phase shifts.

Abstract: A millimeter-wave electronic phase shifter in a dielectric waveguide having a semi-insulating dielectric core and at least one semi-conducting epitaxial layer. A controller affixed to the epitaxial layer is used to apply a bias voltage thereby varying the conductivity of the epitaxial layer and influencing wave propagation in the waveguide.

Abstract: A phased-overmoded, tapered waveguide transition has a central section which is tapered linearly in the longitudinal direction and two end sections which are tapered curvilinearly in the longitudinal direction. One of the end sections and at least a portion of the other end section are overmoded and, therefore, give rise to higher order modes of the desired microwave signals propagated therethrough. The lineraly tapered central section shifts the phase of higher order modes generated at one end of the transition so that at least a major portion of such higher order modes is cancelled by higher order modes generated at the other end of the transition.

Abstract: A mode converter is disclosed which selectively generates a predetermined higher order mode(s) from an incident fundamental mode. This mode converter comprises a dielectric region having an effective-dielectric-constant/thickness profile which is the same as the amplitude profile of the desired higher order mode(s).

Abstract: A phase shifter utilizing a circulator and electronic switches to change the length of a transmission line is disclosed. More specifically, a section of transmission line terminated in a short circuit is coupled to one port of a circulator. Energy exiting the port is reflected by the short circuited transmission line to introduce a phase delay in the signal. A PIN diode is utilized to provide a switchable short across the transmission line to reduce its electrical length thereby reducing the phase delay.

Abstract: A waveguide dimensioned for fundamental mode operation over a given frequency range is rendered substantially dispersionless by including within the waveguide a thin dielectric slab extending parallel to the E-field of the fundamental mode and having a dielectric constant of at least 4 and a thickness across the E-field ranging between 0.01 and 0.25 guide wavelengths at the center frequency of the given range. Appropriate thicknesses for a dielectric member having a given dielectric constant can be selected to provide overcompensation. The series connection of appropriate lengths of an overcompensated waveguide and uncompensated waveguide yield an overall waveguide having a substantially dispersionless characteristic.

Abstract: A microwave phase discriminator is shown to include a microwave bridge network having two pairs of input ports and two pairs of output ports, the phase shift of signals passing through such network being dependent upon which one of the input ports is actuated, a diode detector connected to each one of the output ports, a difference amplifier connected to each pair of diode detectors, a single-pole double-throw switch connected to each input port and commutating switches at the inputs to the corresponding difference amplifiers.

Abstract: A surface acoustic wave convolver (10) with parabolic horns (16, 18), a typical horn (16) having a compensating stub (16a) at the horn input end (16b) disposed centrally on the horn longitudinal axis (19) to maintain the phase coherence at the horn output end Z(16c) of a wave traversing said horn (16).