摘要:
A low profile smart antenna includes an active antenna element carried by a dielectric substrate, and active antenna element has a T-shape. Passive antenna elements are carried by the dielectric substrate, and they have an inverted L-shaped portion laterally adjacent the active antenna element. Impedance elements are selectively connectable to the passive antenna elements for antenna beam steering.
摘要:
A smart antenna includes an active antenna element, a passive antenna element laterally adjacent the active antenna element, and an impedance element selectively connectable to the passive antenna element for antenna beam steering. A ground plane includes a center portion adjacent the active antenna element, and first and second arms extending outwardly from the center portion. The first arm is connected to the impedance element, and the second arm is laterally adjacent the first arm.
摘要:
A folded monopole antenna that supports lower and upper frequency bands may be used in CDMA, WLAN, or other wireless communications systems. The folded monopole antenna may be located in a handset next to a vertical ground plane. The folded monopole antenna may be folded at least twice and connected to the ground plane through a reactance. The dimensions of different sections of the folded monopole antenna define lower and upper frequency band characteristics, and an offset location of an input feed affects the bandwidth of the frequency bands. The reactance between the antenna and ground plane can be selected to fine tune the frequency bands. Various input feeds, including a co-planar waveguide, may be employed. Dynamically adjustable reactances may be used in the input feed and ground line for adapting the antenna to various environments.
摘要:
An antenna having a central active element and a plurality of passive dipoles surrounding the active element is disclosed. The passive dipoles increase the antenna gain by increasing the radiated energy in the azimuth direction. In another embodiment a plurality of parasitic directing elements extend radially outward from the passive dipoles.
摘要:
A smart antenna includes a ground plane, an active antenna element adjacent the ground plane, and passive antenna elements adjacent the ground plane. The passive antenna elements have different sizes for defining different resonant frequencies for increasing a bandwidth of the smart antenna. Dielectric layers having different dielectric constants may also be used for coating the passive antenna elements for defining different resonant frequencies. Impedance elements are connected to the ground plane and are selectively connectable to the passive antenna elements for antenna beam steering.
摘要:
A matrix-fed circular array system includes a plurality of antennas, a plurality of azimuth matrices in communication with the antennas, and a plurality of elevation matrices in communication with the azimuth matrices. The array system forms M×N beams, where M is the number of azimuth beams, and N is the number of elevation beams. In another embodiment, through the use of a Shelton-Butler or Butler matrix which includes a plurality of hybrids, the system outputs omni-directional pancake-shaped radiation patterns that are isolated from each other when a communication signal is input into the system. In yet another embodiment, the system uses a beam forming network including two Shelton-Butler matrices. A first one of the Shelton-Butler matrices creates omni-directional pancake beams that are isolated from each other, and a second Shelton-Butler matrix creates multiple directive beams in an azimuth plane.
摘要:
An antenna for controlling a beam direction both in azimuth and elevation is disclosed. An antenna comprises a ground plane, at least one active element, and a plurality of passive elements. Both an upper half and a lower half of the passive elements are connected to the ground plane with variable reactive loads, whereby elevation angle of the radio beam is controlled by adjusting the variable reactive loads. Alternatively, an antenna may comprise a radio frequency (RF) choke coupled to the ground plane, whereby an elevation angle of the radio beam is controlled by controlling the RF choke. Alternatively, an antenna comprises a variable lens for changing a wave front of a radio wave which is passing through the variable lens, whereby the beam width and direction are controlled by the variable lens.
摘要:
A satellite communication subscriber device includes a smart antenna for generating antenna beams for receiving signals from at least one satellite, and a receiver. The receiver includes a quality metric module for calculating a quality metric on the signals received by each antenna beam. A beam selector is coupled to the smart antenna for selecting the antenna beams. An antenna steering algorithm module runs an antenna steering algorithm for operating the beam selector for scanning the antenna beams, receiving the calculated quality metrics from the receiver for each scanned antenna beam, and comparing the calculated quality metrics. The algorithm selects one of the scanned antenna beams based upon the comparing for continuing to receive signals from the at least one satellite.
摘要:
A directive antenna operable in multiple frequency bands includes an active antenna element and at least one passive antenna element parasitically coupled to the active antenna element. The passive antenna element(s) have length and spacing substantially optimized to operate at (i) a fundamental frequency associated with the active antenna element and (ii) a higher resonant frequency related to the fundamental frequency. Spatial-harmonic current-distributions of the passive antenna elements are used to create the multiple frequency bands of operation. The directive antenna also includes devices operatively coupled to the passive antenna element(s) to steer an antenna beam formed by applying a signal at the fundamental resonant frequency, higher resonant frequency, or both to the active antenna element to operate in the multiple frequency bands.
摘要:
A method and system for managing a cell sectorized by both an angle in azimuth and a distance from a base station are disclosed. A wireless communication system comprises a base station and a cell. The base station comprises an antenna array for generating a plurality of directional beams which are steerable both in azimuth and elevation. The cell is sectorized into a plurality of sectors defined in accordance with an angle in azimuth and a distance from the base station. At least one directional beam serves each sector. Beams serving adjacent sectors overlap each other, and a softer handover in a cell is performed in the overlapping region.