Maxtena, Inc.

Nathan Cummings

Carlo DiNallo

Stanislav Licul

Simone Paulotto

Stanislavv Licul

Systems for maintain pointing of a phased array antenna in a direction maximizes to an extent possible the effective antenna gain is provided. The system includes a gyroscope and a Kalman Filter. The Kalman filter estimates an antenna pointing direction for each successive time step based on gyroscope readings and based on the results of a local search for maximum gain performed in the neighborhood of a previous antenna pointing direction.

Antenna array pointing direction estimation and control

A system includes a phased array antenna that is used to emulate antennas that have larger solid angle coverage and lower gain compared to a single beam of the phased array antenna. This is achieved by switching between beams of the phased array antenna while receiving a wireless communication signal and summing representations of signal energy received using the different beams. The system can be used to narrow down the angular coordinates of a transmitting satellite by emulating antenna patterns that cover portions of a search space. The system can also be used to determine a channel discriminator (e.g., frequency, code, time slot) that defines a signal being transmitted.

System in which a phased array antenna emulates lower directivity antennas

A phased array antenna for an earth terminal for a low earth orbit satellite communication system. The phased array antenna includes a set of Quadrafilar Helical Antenna's (QHAs) elements that produce a peak directivity far off-axis which partially compensates for the angular dependence of satellite systems gain which peaks at relatively lower angle. To attain the desired angular dependence of the gain and operability at high zenith angles, the QHAs are preferably spaced apart by a distance between 0.4&#x3bb; and 0.45&#x3bb;, includes filaments that have a helical pitch angle &#x3b1; of between 62&#xb0; and 84&#xb0;.

Phased array antenna with improved gain at high zenith angles

A multi-mode, multi-band antenna system for a handheld wireless device includes a Quadrafilar Helix Antenna (QHA) that radiates circularly polarized waves is fed by a co-axial cable. The co-axial cable is also used in combination with the QHA as a monopole antenna. Because of the distinct electromagnetic field patterns of the QHA versus the combination of the QHA and the co-axial cable operating as a monopole antenna, the cross coupling between the two modes is low. In certain embodiments the co-axial cable can itself be formed into a helix in order to reduce the physical length of the antenna system while maintaining an electrical length desired to supported certain frequency bands in the monopole mode. According to certain embodiments a post which also serves to increase the effective electric length of the co-axial cable and thereby support a lower frequency band is provided along the centerline of the QHA.

Multi-mode, multi-band antenna

Antennas that include an inner set of four helical antenna elements and a co-axially arranged outer set of four helical antenna elements. The helical winding directions of the two sets of elements may have the same handedness or opposite handedness. Certain embodiments provide for switch handedness of circularly polarized radiation of the antennas and certain embodiments provide for shifting the directivity of the antenna pattern in polar angle. Systems in which the antennas are used and methods of use are also taught.

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Gaithersburg, MD, United States of America

Nathan Cummings