Hughes Aircraft Company

Other

Hughes Electronics Corporation

Maury Microwave, Inc.

Vubiq Networks, Inc.

Robert L Eisenhart

Jennifer M Butler

Dan M Goebel

Gary R Simpson

Michael Gregory Pettus

Pyong K Park

Ralston S Robertson

Louis A Kurtz

Richard J Maury

Bela B Szendrenyi

Ralston S Robertson, Jr

Eric L Holzman

A printed circuit board assembly comprising a plurality of layers. At least one of the plurality of layers is formed of a dielectric material and has an extended portion extending beyond the other layers in the plurality of layers. A first metallic layer is located on at least a portion of the extended portion of the dielectric layer. The first metallic layer and the dielectric layer are configured to form a launch transducer comprising one or more transmission lines and a transducer element coupled to the one or more transmission lines. The transducer element is configured to propagate millimeter wave frequency signals.

Waveguide interface and printed circuit board launch transducer assembly and methods of use thereof

A method of generating an RF field reflection, including positioning a grid wall in front of a conductive wall, launching RF energy at the grid wall and the conductive wall, including first and second linearly polarized orthogonal components, and reflecting one component from the grid wall set and allowing the other component to pass through the grid wall set with little reflection to reflect from the conductive wall.

Wall configurations for generating uniform field reflection

A microwave oven includes an oven cavity, defined by flat, electrically conductive oven walls. A microwave source generates microwave energy including orthogonal linearly polarized components into the oven cavity from a port formed in a first one of the oven walls. A grid wall of conductive lines parallel to a polarization direction is spaced from a second oven wall by a distance nominally equivalent to a quarter wavelength of the microwave energy.

A slotted line tuner, also capable of operation as a fully automated tuner, to provide arbitrary termination in high frequency waveguide media for use with frequencies of interest between 1 and 1000 GHz is disclosed. The electrical tuner is adapted to match the impedance of two waveguide media, or enhance or modify the characteristic impedance of a media relative to that of another one. The tuner utilizes a non-conductive rectangular bar vane made out of low loss, low dielectric constant material as the probe, with special gold plated areas, that is inserted through the slot of the line into a reduced height waveguide. The position and depth of this gradual probe penetration creates a continuously variable tuning of the complex impedance, ranging from a very low reflection state up to high reflection states together with an unlimited capability of phase change in its reflection. The non-conductive probe structure assures that the propagation of the coaxial guided wave modes, and especially the coaxial TEM mode, within the slot area are suppressed, thus eliminating a typical source of leakage. A series of slots is formed in the waveguide housing perpendicular to the main slotted line, to form a multi-choke filter that prevents the propagation of parallel plate modes within the slot area thus further reducing leakage and excessive insertion loss.

Reduced height waveguide tuner for impedance matching

Microwave amplifiers are disclosed having a hollow helix slow-wave structure coupled directly to input and output waveguides. This helix-waveguide coupling structure couples the TEM mode of the helix to the TE10 mode of the rectangular waveguides and also defines ports communicating with the helix interior. Heating of the helix during high-power operation can be removed by cooling liquid pumped through the helix via these ports. The helix is surrounded by a cylindrical housing containing a low-pressure ionizable gas which forms a plasma channel that focuses the electron beam without the need for surrounding magnetic structures. A plasma cathode electron gun is arranged to inject an electron beam through the helix. Backflowing ions from the housing are harmlessly absorbed into the face of the plasma cathode. The microwave amplifier is converted to a backward wave oscillator by coupling a load to one of the waveguides.

Plasma-assisted tube with helical slow-wave structure

Multiple radio frequency (RF) outlet ports are provided along the side of a slow wave tube to establish a distributed RF output in response to the transmission of an e.sup.- beam through the tube. The tube has a periodically rippled inner surface, and the outlet ports are spaced along the tube by substantially integral numbers of ripple periods. When implemented as a backward wave oscillator, RF power is extracted during a single pass through the tube; a travelling wave tube amplifier implementation is also possible. The separation of the RF extraction from the absorption of the e.sup.- beam at the end of the tube eliminates RF reflections and permits water cooling of the e.sup.- beam absorber. The RF extraction ports are also preferably configured as built-in mode converters from a TM.sub.01 cylindrical tube mode to a TE.sub.10 rectangular extraction mode, with four symmetrically arranged rectangular extraction waveguides at each extraction location combining their energies into a single TE.sub.10 output. Reductions in the cylindrical tube diameter after each extraction location reflect radiation back through the tube to cancel back-scattered radiation losses from the extraction ports.

RF source including slow wave tube with lateral outlet ports

The mode convertor employs two intermediate modes, a coaxial TEM and a rectangular waveguide TE.sub.10 mode, in the transition between the TM.sub.01 and TE.sub.11 circular waveguide modes. The coaxial line provides isolation while acting as a mode filter between the device input and output ports. The rectangular waveguide provides a wide mode separation ratio between the TE.sub.10 and TM.sub.11 modes. The TE.sub.10 mode then transitions into the TE.sub.11 in the circular output waveguide. The coaxial section keeps the output TE.sub.11 mode from scattering back to the input, and the rectangular section keeps the TM.sub.01 from being excited in the output.

Wideband TM.sub.01 -to-TE.sub.11  circular waveguide mode convertor

A wideband convertor for mode conversion between a TEM coaxial mode in coaxial line and the TM.sub.01 circular waveguide mode in circular waveguide. The convertor takes advantage of the somewhat similar electric field configurations of the two modes. To physically match the coaxial line to the waveguide, a tapered section is employed to provide a gradual diameter transition.

Wideband coax-to-TM.sub.01 converter and testing system using the same

A polarimetric antenna (20) comprises a length of circular waveguide (30) having a sidewall (32) with a cylindrical internal surface (34). The sidewall (32) has two longitudinal slots (38) that extend parallel to a longitudinal axis (36) of the waveguide (30) and are symmetrically positioned with respect to the circumference of the circular waveguide (30). A first rectangular waveguide (40) communicates with one of the longitudinal slots (38), and a second rectangular waveguide (42) communicates with the other longitudinal slot (38), but is short circuited by a closure (44) at one end thereof. A transverse closure (46) is positioned over the circular waveguide (30) at one end, the closure (46) having a first and a second transverse slot (48, 50) therein. These slots (48, 50), which are preferably arcuate in form, are positioned symmetrically with respect to a longitudinal axis (36) of the circular waveguide (30). A third rectangular waveguide (52) is in communication with the first transverse slot (48), and a fourth rectangular waveguide (54) is in communication with the second transverse slot (50). The two rectangular waveguides (52, 54) are preferably excited through an E-plane folded magic Tee (58). This antenna (20) is used to radiate sub-microwave, microwave, or millimeter wave energy in applications such as a cassegrain tracking antenna (22).

Polarimetric antenna

A loadline bias circuit for biasing solid state devices operable at high frequencies is disclosed. The source impedance of the dc bias circuit is adjusted to influence the RF device characteristic, thereby creating a way to optimize the device performance. The bias circuit comprises a resistive element coupled in series connection with a constant voltage source or in parallel connection with a constant current source. The bias circuit may be adapted to set an optimum relationship between the bias current and bias voltage so that when one bias parameter changes, the other will automatically compensate with an appropriate change as well. The resistive element provides a device operating range throughout which the bias power supplied to the device is substantially constant. The value of the loadline, that is, the resistive element, can be selected to optimize particular performance parameters.

Bias circuit for solid state devices

A polarized, mitered corner (32) is constructed using a multiple surface reflector in a square waveguide corner. The multiple surface reflector (34) provides a mitered corner having one effective miter size for the E-plane mode and a different effective miter size for the H-plane mode (42, 44). The surfaces may comprise ridges which are parallel to the E-field in one of the two modes, so that the ridges behave as the reflecting surface for that mode while the backplane, upon which the ridges are formed, serves as the reflecting surface for the other mode. An alternate embodiment wherein the two reflecting surface comprise a plurality of parallel wires, is also disclosed.

Matched dual mode waveguide corner

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.

Microwave power combiner with alternating diode modules

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

Coaxially coupled tunable oscillator using a ridge waveguide

An electrical coupler for transmitting high frequency electrical signals from a coaxial transmission to a microstrip transmission line. The coupler is adapted to match the characteristic impedance of the two media and the electromagnetic field patterns of the two media at the interfaces therewith. The coupler provides a transition having a very low reflections at frequencies at least up to 18 GHz. The preferred embodiment transitions utilize a cylindrical outer conductor and an inner conductor which is centered relative the outer conductor at the coaxial end of the coupler and gradually shifted offcenter so that it is very near the outer conductor at the microstrip end of the coupler. The characteristic impedance of the coupler is maintained at a constant value by appropriate variation of the inner conductor. Other features are disclosed.

Growing community of inventors

Woodland Hills, CA, United States of America

Robert L Eisenhart