California Amplifier, Inc.

California Amplifier Company

Calamp Corp.

Mark J Lange

Edward E Gabrelian

Vishwanath G Upadhye

Andrew H Burton

Lou Altreche

The present invention provides for inexpensive transparent microwave antennas with high efficiency. Conductors for the antennas are formed from metallic meshes with a net transparency greater than 70% and supported by a clear substrate. The associated antenna gain efficiencies are greater than 50%.

High-efficiency transparent microwave antennas

Paraboloidal grid reflectors and antennas are provided which are lighter and have less wind loading because they efficiently realize selected front-to-back ratios by recognizing the angular distribution in typical differential path losses and feed gains. In particular, the reflectors are formed with adjacent pairs of parallel elongate members that are positioned at respective angles &thgr; from the paraboloidal vertex and spaced apart by respective spaces S that generally increase with increased angle &thgr;. In some reflector embodiments, the spaces S increase with increased angle &thgr; for a contiguous majority of adjacent pairs and may be constant for a contiguous minority that typically adjoins the vertex. In other reflector embodiments, the spaces S increase with increased angle &thgr; for all of the adjacent pairs.

Grid antennas and methods with efficient grid spacing

Antenna structures are shown that reduce fabrication and assembly time and cost, increase antenna reliability and enhance antenna performance. These structures include resilient flanges that are formed by a slotted ground plane and a rear ground plane which together surround a feed circuit. The ground planes are simply pressed together to engage the flanges in an overlapped and resiliently interlocked relationship. In other antenna structure, a capacitance probe forms a part of a coaxial transition. One end of the probe forms a capacitance face and the transition is configured to automatically space the capacitance face from a trunk end of the feed circuit. A second end of the probe is available for coupling signals to antenna-associated circuits (e.g., a downconverter). A pressed-together signal-transmission path through these circuits is formed with spring-loaded sockets. One socket receives the capacitance probe's second end and the other receives the center pin of an external coaxial connector. The sockets can form the access ports of the antenna-associated circuits or form part of a direct path to the antenna's exterior. In other structures, an antenna that includes a slotted ground plane and a feed circuit is converted to a slot-coupled patch array antenna with a polymer sheet that carries a plurality of metallic patches and a dielectric array spacer. These elements are simply pinned to the ground plane and feed circuit with a plurality of dielectric pins.

Slot-coupled array antenna structures

Antenna

An end-fire array antenna achieves improved performance with an array of radiative members that are arranged collinearly between an array first end and an array second end and a divergent reflector which is arranged collinearly with the radiative members. The radiative members are spaced to facilitate radiation and reception of electromagnetic signals in an antenna direction which extends from the array second end and the divergent reflector is spaced from the array first end to enhance this radiation and reception. A wall of the reflector preferably diverges from an antenna axis by an angle in the region of 24 to 48 degrees. The divergent reflector terminates in an open end which has a transverse width that preferably exceeds 1.4 .lambda..sub.dsgn wherein .lambda..sub.dsgn is the design wavelength of the antenna. In-service antennas are modified with a divergent reflector that is configured for coupling to an existing antenna back wall or antenna cup.

End-fire array antennas with divergent reflector

An antenna/downconverter directed to the subscription television distribution industry having low cross polarization and broad bandwidth. The antenna/downconverter includes a director mounted to a housing which defines a reflector cup, side lobe suppression rim and a housing defining a chamber which provides environmental protection for downconverter electronics. Received microwave energy is coupled to the downconverter electronics from a point radially inward from the perimeter of a first receive disc axially spaced within the reflector cup using a probe surrounded by a conductive probe shield integral to the reflector cup. A second receive disc having a different radius than the first receive disc and axially spaced within the reflector cup is parasitically coupled to the first probe. The second receive disc additionally includes wings coupled to the perimeter of the reflector cup for shunting cross-polarized microwave signals. The housing defines a plurality of pairs of jaws which facilitate alignment to cross-polarized microwave signals when an installer receives a mounting mast in a selected one of the jaws.

Low cross polarization and broad bandwidth

An antenna/amplifier includes a waveguide and an amplifier system. The amplifier and signal lines which terminate in orthogonal probes are carried on a common substrate. The orthogonal probes are spaced from a waveguide wall and isolated for good cross polarization by a post which extends from the wall. The probes have probe tips which are spaced from the post by a probe space. Parameters which include the probe space, the impedance of the signal lines and the length of the signal lines can be selected to present an optimum impedance to low-noise amplifiers of the amplifier system.

Antenna/amplifier and method for receiving orthogonally-polarized signals

An antenna suitable for use at subscriber sites in a television distribution system having a high front-to-back ratio and optimized for reception within multiple frequency bands. The antenna is comprised of multiple tapered antenna stages including a primary antenna stage for receiving a primary frequency band and a coupling antenna stage for matching the impedance of the primary antenna stage to either a coaxial cable or downconverter electronics. The multiple antenna stages are alternatively formed from either a stamping of a metal sheet or a double sided printed circuit board.

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Camarillo, CA, United States of America

Mark J Lange