2632results about "Particular array feeding systems" patented technology

An apparatus and method to reduce the size of a microstrip antenna without sacrificing antenna efficiency too much are described. The antenna structure includes discontinuity of strip width in the middle of the antenna patch to reduce the size of the antenna at a given resonant frequency. The antenna structure further includes a plurality of patches of differing widths connected to each other at junctions. The junctions are placed symmetrically to ensure maximum radiation at the boresight and also to further reduce cross-polarization levels. A coaxial feed is connected at a predetermined location near the center of a patch, having a narrower width, in order to match the input impedance of the antenna to the coaxial feed.

An antenna array (e.g., microstrip patch antenna) operates in a manner that exploits the particular susceptibility of the mutual coupling effects between radiating elements in the array. Various differential-mode excitation schemes are provided for determining optimal differential-mode voltages or optimal differential-mode currents that are applied to the radiating elements (e.g., microstrip patches) to thereby achieve certain desirable radiation characteristics including, for example, aiming a radiated beam in a prescribed direction, steering the beam, shaping the radiated beam, and / or optimizing the gain of the antenna in a specified direction.

Digital beamforming is provided for use with electronically scanned radar. In an aspect, the present invention provides enhanced sensitivity, wide angle or field of view (FOV) coverage with narrow beams, minimized number of receivers, reduced sidelobes, eliminated grating lobes and beam compensation for target motion. In an aspect, the present invention employs a uniform overlapped subarray feed network, a time multiplexed switch matrix, and a restructured digital signal processor. Antenna channels share a receiver, rather than maintain a dedicated receiver for each antenna element, as in conventional systems. In an aspect, Doppler / frequency filtering is performed on each antenna element or subarray output prior to digital beamforming. Further, Doppler compensation is employed following Doppler / frequency filtering, followed by digital beamforming.

A telecommunications satellite having a phased array antenna, wherein the beam-forming function within the phased array is simplified by partitioning it into two stages, in which the sub-array stage relates to a fixed, or infrequently changed,set of overlapping sub-arrays and the main stage provides the main pattern reconfiguration, typically in the form of multiple reconfigurable spot beams within a defined coverage region. The key advantage lies in the significant reduction in number of second stage beam-forming control points (at which independent amplitude and phase is applied) when compared with a conventional phased array (where amplitude and phase control is applied for each element of the array). The sub-array stage beam-forming may be implemented in analogue technology. The main beam-former may be implemented in digital technology, where the key processing functions of A / D or D / A conversion, frequency (de)multiplexing and digital beam-forming all scale with the number of control points.

The invention discloses a high-different frequency isolation broadband double-frequency base station antenna array, which comprises at least one high-frequency antenna unit, a low-frequency antenna unit and a floor board, wherein when one high-frequency antenna unit exists, the high-frequency antenna unit is placed at one side of the floor board, when multiple high-frequency antenna units exist, the high-frequency antenna units are placed at two sides of the floor board respectively, each high-frequency antenna unit comprises multiple oscillator arms and a Balun, the oscillator arms are connected through a distributed inductor, and feeding is carried out through the Balun; the low-frequency antenna unit is placed in the middle of the floor board and comprises multiple oscillator arms and a Balun, the oscillator arms are connected through a distributed capacitor, feeding is carried out through the Balun, the Balun is provided with a feeder line and an H-type microstrip branch, and the H-type microstrip branch is connected with the feeder line. In a condition of not cascading filters, high isolation in a condition in which the distance between the different-frequency antenna units is small and the floor board is small can be realized, insertion loss of a filter is avoided, a stable pattern in a broadband is realized, and due to a decoupling structure, the volume of an antenna unit is not added extraly.

A compact multiple-frequency Z-type Inverted-F antenna includes a dielectric substrate having a horizontal axis and a vertical axis perpendicular to the horizontal axis. A feed point is disposed along the horizontal axis on a first side of the vertical axis and a ground strip is disposed along the horizontal axis on a second side of the vertical axis opposite the feed point. A plurality of wedge-shaped radiating traces is arranged symmetrically with respect to the horizontal axis and disposed on the first side of the vertical axis. A plurality of wedge-shaped ground traces symmetrical to the plurality of radiating traces with respect to the vertical axis are disposed on the second side of the vertical axis.