Hughes Aircraft Company

Harmon H Keeling

Thomas Hudspeth

Richard V Basil, Jr

A hybrid coupler is of the type known as a transverse electromagnetic mode, coupled transmission line coupler. The hybrid coupler is formed within a plate of metal by milling out channels of square cross-sections therein. The walls of the channels serve as outer conductors of coaxial lines, there being inner conductors of square cross-section positioned within the channel. A diagonally disposed window crosses the intersection of the ports and includes a separator. The central conductors of the respective coaxial lines are joined by diagonally disposed segments of inner conductor such that each pair of coaxial lines is so joined. Each pair of lines provides a pair of ports. The line segments are spaced apart by a spring-loaded separator for rigidly maintaining a coupling distance.

Square conductor coaxial coupler

An adapter of a coaxial transmission line to a waveguide is provided for connecting the waveguide to a microwave circuit of coaxial lines which is formed by milling out the lines within a plate of a soft metal. The coaxial transmission lines are of rectangular, preferably square, cross-section with the outer conductors thereof being provided by the walls of the channel. The inner conductors of the coaxial lines are rod-shaped, the inner conductors also being of rectangular or square cross-section. An aperture is provided in an outer wall of the coaxial line. A stem connects with an inner conductor and passes through the aperture to extend outwardly therefrom. A waveguide is positioned with its propagation axis parallel to the stem, the waveguide enclosing the stem and being secured to the outer walls of the coaxial lines. The stem is placed adjacent the inner wall of the waveguide, but spaced apart therefrom to support a transverse electromagnetic wave. A dipole element of planar shape extends transversely of the waveguide and is secured at an edge thereof to the terminus of the stem. The dipole element launches a propagating mode of wave within the waveguide while receiving its energization from the transverse electromagnetic wave propagating along the coaxial line and along the stem.

Coaxial line to waveguide adapter

A crossover for a microwave circuit constructed within a plate includes intersecting square-shaped coaxial transmission lines, each of which is formed by machining channels within the plate, with square-shaped central members disposed along the axes of the channels and insulated from the side walls thereof. The plate is made of an electrically conducting material to provide for the structure of a coaxial line of which the members thereof have a rectangular, preferably square-shaped, cross-section. At the intersection of two of the transmission lines, a septum is placed, the septum being parallel to the plane of the plate. The septum is located halfway between the top and the bottom portions of the channels. An inner, or central, conductor segment of reduced cross-section is slung beneath the termini of rod-shaped members in one line so as to pass beneath the septum and to provide for the structure of a coaxial transmission line beneath the septum. A corresponding conductor segment is located above the septum and disposed on termini of the central conductor members of the other one of the intersecting transmission lines. A cover encloses the channels of the plate. The crossover segment of the second transmission line passes between the cover and the septum to provide the structure of a coaxial line between the cover and the septum. Matching structures in the form of a miter at the end of each center conductor reduces reflection at the junction of the segment at the septum with the balance of the transmission line. The foregoing segments are approximately one-quarter wavelength of the microwave frequency.

Coaxial transmission line crossing

Apparatus for processing microwave signals at two predetermined frequencies. Signals at a first predetermined frequency are received or transmitted at one end (input port) of a microwave transmission line whose other end is utilized as a common output port for transmitting and receiving signals at both predetermined frequencies. A band rejection portion is provided which comprises first and second rejection resonators orthogonally disposed along the transmission line at two predetermined positions. A bandpass portion, comprised of a plurality of collinearly aligned bandpass resonators, is disposed at a third predetermined position along the transmission line. Signals at a second predetermined frequency are transmitted or received at a second input port which is part of the bandpass portion. All resonators are capacitively coupled together and to the transmission line. Signals at both predetermined frequencies may be applied to the first and second input ports and are combined in the transmission line by the filtering action of the resonators. Conversely, signals having both predetermined frequencies may be applied to the output port and separated in the transmission line such that signals at the first predetermined frequency are provided at the first input port and signals at the second predetermined frequency are provided at the second input port. Also, signals at one frequency may be transmitted by way of the diplexer while signals at the second frequency are received thereby, or vice-versa.

Microwave diplexer

A wideband synchronously pumped parametric amplifier is described that features minimum time delay along with wide bandwidth, a low noise figure and cost for advantageous use in receivers designed to receive television signals from a satellite through a relatively small antenna, the amplifier obtaining maximum bandwidth by the use of two diodes in parallel and two double-tuned circuits, where the diode capacities are large enough to swamp parasitic and coupling capacitances.

Balanced synchronous parametric amplifier

A TEM-mode transmission line switch coupling essentially all input power at a first port to a fourth port when in its uncoupled position and coupling a predetermined significant fraction of the input power to a second port with the remainder coupled to the fourth port when in its coupled position, the switch including a relatively wide spaced parallel transmission line section with a rotatable conductive vane disposed between the parallel lines to allow coupling of power between the lines in the coupled position and inhibit such coupling in the uncoupled position.

Transmission line switch

A simplified waveguide switch is disclosed having a rotatable quarter wave plate for generating selected amounts of right hand and left-hand circular polarized waves. A linearly polarized signal, in the TE.sub.11 mode, is launched into a cylindrical waveguide member. A quarter-wave plate is disposed within the cylindrical waveguide and imparts a right or left-hand circular polarization to the linear wave depending upon the orientation of the quarter wave plate with respect to the linear wave. The rotation angle of the quarter wave plate is adjusted by a stepping motor.

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Lake Isabella, CA, United States of America

Harmon H Keeling