MXPA96005822A - Micro-fran antenna provision - Google Patents

Abstract

An antenna is disclosed for a base station in a mobile radio communication system, with at least one base station and at least one mobile station. The antenna comprises a micro-fringe antenna arrangement, with a matrix of micro-fringe patches, with at least two columns and two rows. In addition, a plurality of amplifiers are provided, in which each amplifier is connected to a different column of micro-fringe patches. Finally, the beamformers are connected to each power amplifier, to determine a direction and configuration of the narrow antenna lobes, generated by the columns of the micro-fringe patches.

Description

DISPOSAL OF ANTENNA OF MICRO-STRIPES Field of the Invention The present invention relates to an antenna, for use in a base station of a cellular communications system and, more particularly, to a micro-strip antenna arrangement, which improves the performance of the base station , increasing the profit and reducing the problems of "interference." Antecedents of the Invention The cellular industry has made notable advances in commercial operations in the United States of America, as in the rest of the world. major metropolitan areas has far exceeded expectations and has left behind the capacity of the system.If this trend continues, the effects of rapid growth will soon be achieved even in smaller markets.Novel solutions require thus meet these growing capacity needs, as well as maintaining high quality services and avoiding the rise in prices. As the number of cellular users increases, the problems associated with the interference of joint channels becomes of increased importance.

Figure 1 illustrates ten C1-C10 cells in a mobile, cellular, traditional radiocommunications system. Normally, a mobile radio cellular system must be carried out with more than ten cells. However, for purposes of simplicity, the present invention can be explained using the simplified representation, illustrated in Figure 1. For each cell, C1-C10, there is a basic station B1-B10, with the same reference number, as the corresponding cell. Figure 1 illustrates the basic stations located in the vicinity of the center of the cell and having antennas or nidirectionals. Figure 1 also illustrates nine mobile stations, M1-M9, that can be moved within a cell and from one cell to another. In a traditional cellular radio system, you will usually have more than nine cellular mobile stations. In fact, there are typically many times the number of mobile stations as that of the basic stations. However, for the purposes of explaining the present invention, the reduced number of mobile stations is sufficient. Also illustrated in Figure 1 is a mobile switching center, "MSC". This mobile switching center, MSC, illustrated in Figure 1, is connected to all die ?: base stations B1-B10 by cables. The mobile switching center, MSC, is also connected by cables to a fixed switching telephony network or a similar fixed network. All cables from the mobile switching center, MSC, to the base stations, B1-B10, and the cables to the fixed network are not illustrated. In addition to the mobile switching center, MSC, illustrated, there may be many additional mobile switching centers, connected by cables to the base stations, in addition to those illustrated in Figure 1. Instead of the cables, other means may also be used, for example, fixed radio links, to connect the base stations to the mobile switching centers. The mobile switching center, MSC, base stations and mobile stations are all controlled by computer. In traditional mobile radio cellular systems, as illustrated in Figure 1, each base station has an omnidirectional or directional antenna for the emission of signals through the entire area covered by the base station. As a result, the signals of the particular mobile stations emit throughout the coverage area, regardless of the relative positions of the mobile stations using the system. In the base station, the transmitter has a power amplifier for the carrier frequency. The amplified signals are combined and connected to a common antenna, which has a wide beam of azimuth. Due to the broad beam width of the common antenna, for example 120 to 360 degrees of coverage, the antenna gain is low and there is no spatial selectivity of use, which results in interference problems. More recent techniques have focused on using linear power amplifiers, which are suitable for amplifying a combined signal of several carrier frequencies, which then feed the combined signal to a common antenna, which also has a wide beam of azimuth. However, these systems also suffer from interference problems. Another type of antenna that has been developed is the micro-strip antenna, which is illustrated in Fiqura 2. Basically, this micro-strip antenna consists of a conductive path 10, formed of a dielectric substrate 12, and a plane to ground 14 at a distance from path 10. This ground plane can be formed on the opposite side of substrate 12, or the spacing between the patch and the ground plane can be filled, fully or partially with air, foam or some other dielectric material. Using the well-known fringe line technology, the antenna elements can be chemically etched onto a laminated copper board. A number of elements can then be placed in the same laminate. The elements are fed in series, in parallel or both, by a supply network of connection lines 16, in the same layer as the elements or in another layer. The frequency and impedance characteristics of the micro-fringe antenna are a function of the antenna size, the placement of the input power and the permissiveness of the substrate. In addition, the polarization sensitivity of the antenna can be vertical or horizontal, or both, depending on the arrangement of the conductive patches 10. However, the use of microwire antennas has been limited due to its operating bandwidth inherently narrow. The micro-fringe antenna elements have a relatively narrow bandwidth, traditionally of 2-5 percent. The coverage of a wider frequency band can be achieved through the use of stacked elements or slit coupled elements. In an attempt to reduce attenuation variations in the received signal, current base stations use a special diversity, in that two receiving antennas are typically separated by 20 or 30 wavelengths. However, the diversity of the receiver currently used is less attractive with narrow beam antennas and high gain, since they are more expensive and larger, providing both visual and assembly problems. SUMMARY OF THE INVENTION It is an object of the present invention to improve the performance of a base station by increasing the gain of the antenna in the base station, while reducing the problems of "interference." It is another object of the present invention to make available the technology of linear power amplifiers for use in the base stations It is another object of the present invention to provide a polarization diversity in a base station which can, for example, replace the spatial diversity arrangements In accordance with one embodiment of the present invention. invention, there is described an antenna for a base station in a mobile radiocommunications system, with at least one base station and at least one mobile station.The antenna comprises a micro-fringe antenna array, with a matrix of microchip patches. strips and at least two columns and two rows.In addition, a plurality of amplifiers is provided, in which each amplifier of po Tencia connects to a different column of micro-fringe patches. Finally, beam-forming elements are connected to each power amplifier, to determine a direction and configuration of the narrow lobes of the antenna, generated by the columns of the micro-fringe patches. In accordance with another embodiment of the present invention, an antenna is described for a base station and a mobile radio communication system, the antenna comprises a micro-fringe antenna arrangement, comprising a matrix of micro-fringe patches with at least two columns and two rows. A plurality of low noise * '"or interference amplifiers are used to filter and amplify the signals received by the micro-fringe antenna array, in which each low noise amplifier is connected to a different column of micro-fringe patches. The beam-forming elements are connected to each low-noise amplifier to determine a direction and configuration of the narrow antenna lobes, generated by the columns of the micro-fringe patches Brief Description of the Drawings The above objects and others and the novel features of the present invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings, however, it will be understood that the drawings are for illustrative purposes only and are not intended as a definition of the LIMITS OF THE PRESENT INVENTION Figure 1 illustrates a portion of a cellular, mobile, communications system, which has das, a mobile switching center, base stations and mobile stations. Figure 2 illustrates a micro-fringe antenna. Figure 3 illustrates a micro-fringe antenna arrangement, according to one embodiment of the present invention.

Figure 4 illustrates another micro-fringe antenna arrangement, according to another embodiment of the present invention. Figure 5 illustrates another micro-fringe antenna arrangement, according to another embodiment of the present invention. Figure 6 illustrates yet another micro-fringe antenna arrangement, according to another embodiment of the present invention. Detailed Description of the Invention The present invention is intended to be used primarily in base stations in cellular communications systems, although it will be understood by those skilled in the art that the present invention may also be used in several other communications applications. According to one embodiment of the present invention, a micro-fringe antenna arrangement, as illustrated in Figure 3, can be used to increase the gain of the base station signals, while decreasing interference throughout the system. The array 30 of the antenna consists of a matrix of micro-fringe patches 32, which are formed above a common plane 34 to ground. The elements in each column are connected either in parallel or in series, or both, by connecting the lines 40. While Figure 3 illustrates six columns and four rows of patches, those skilled in the art will understand that the antenna arrangement may consist of of any plurality of columns and rows. Each patch column is connected to a different power amplifier 36, in a transmission direction and a different low noise amplifier 42, in the reception direction, as illustrated in Figure 4. In addition, each patch column can also to be connected to a plurality of power amplifiers in the transmission direction and a plurality of low noise amplifiers in the reverse direction. Likewise, the patch columns can also be connected to the linear power amplifiers. These power amplifiers and low noise amplifiers are connected to a beam forming apparatus 38, which creates antenna beams with the desired configurations in the desired directions. The antenna arrangement can generate a plurality of narrow azimuth beams or lobes, where the direction and configuration of the antenna beams are determined in the beam forming apparatus 38 by the signal and phase amplitude relationships between the different columns. As a result, the base station can use the narrow beams, which have a greater gain, to emit and receive signals from the mobile stations in the coverage area of the base station. Another important consideration is the desire to suppress the side lobes of each antenna beam. Beam formation can be carried out in a variety of ways, such as digital beam formation, analog beamforming, or by a beamforming matrix, such as the Butler matrix. The analog beamformers orient the beam by introducing a time delay independent of the frequency, while the digital beam formation usually involves a phase delay, which is equivalent to the time delay in the operating frequency. A digital beam formation system usually has a relatively simple receiver for each element, which makes a down-conversion of the frequency in the I and Q channels (in phase and in quadrature) for an A / D converter. The formation of real-time beams takes place by multiplying these complex pairs of samples by appropriate quantities in the integrated multiplication / accumulation circuits. The output of the arrangement is formed of: Output of the disposition =? V "Wn e'1 2" ^? N? Cn n = 0 where: Vn = complex signal from the channel nes; LIno / n = measurement coefficient -j 2 p (< *) sin 0? = Orientation phase offset Cn = correction factor.

Corrections may be necessary for several reasons. These reasons include errors in item position, the effects of temperature and the difference in behavior between those elements embedded in the arrangement and those near the edge. Thus, by configuring and directing the narrow beams of the antenna, a plurality of these narrow beams can be used to simultaneously cover a large sector using the same antenna arrangement. The present invention can use an adaptive algorithm to select the most feasible measurements functions for the antenna. One such adaptive algorithm is described in the Patent Application of E. U. A., No. 08 / 95,224, filed on February 10, 1994, which is incorporated herein by reference. In the antenna array, the patches in each column are polarized. The polarization can be vertical or horizontal, or have a double polarization, with two orthogonal polarization components. These two orthogonal components can, for example, be vertical and horizontal or diagonal polarization components. In simultaneous double polarization, the two orthogonal polarized signals are combined separately for each column, and connected to separate channels in the radio unit. The step of combining the signals can use any of the known combination schemes, for example, selection diversity, maximum ratio combination, etc. The arbitrary elliptical polarization state can then be obtained in both the transmission and reception directions. Since the variations in attenuation are independent for the two orthogonal polarizations, the polarization diversity can be used to encompass the possibility of suppressing further interference and reducing attenuation variations. This will eliminate the need to use diversity of space. Also, due to the high gain of the antenna in the distributed power amplification, the present invention reduces the power level of each power amplifier, thus facilitating the requirements in the linear power amplifier technology. The system can also have the amplifiers and the apparatus that forms permuted beams, as illustrated in Figures 5 and 6. The amplifiers amplify the signals in the channels corresponding to specific antenna beams, in which the configuration and directions of the Beams are determined by the measurements of the apparatus that you make, in that case. The permuted system has the advantage that independent channels do not require coherent amplifiers. In addition, the detection of faults of an amplifier is easy, since each amplifier is associated with a specific channel. Also, by placing the amplifiers between the antenna elements and the beam-forming apparatus, the loss of the system in the beam-forming apparatus is reduced, the output power levels are also reduced due to the distributed power amplification and the possibility of the elegant degradation of the performance of the system, when an amplifier failure occurs. It will be appreciated by ordinary experts in the art that the invention can be carried out in other specific ways, without departing from the spirit and its basic character. The modalities, currently described, are considered, therefore, in all aspects as illustrative and not restrictive. The scope of the invention is indicated by the appended claims, instead of the foregoing description, and all changes within the meaning and range of their equivalences are intended to be considered within the invention.

Claims (24)

1. CLAIMS 1. An antenna for a base station, in a mobile radio communication system, with at least one base station and at least one mobile station, this antenna comprises a micro-strip antenna arrangement, which includes a matrix of micro patches -franks, with at least two columns and two rows; a plurality of power amplifiers, in which at least one power amplifier is connected to each column of the micro-fringe patches; and beam-forming elements, connected to each power amplifier, to determine the direction and configuration of the narrow lobes of the antenna, generated by the columns of the micro-fringe patches. The antenna, according to claim 1, in which the signals to the orthogonal polarized directions are given with an amplitude relation and a relative phase shift, in order to create an arbitrary elliptical polarization state. An antenna, according to claim 1, in which at least one column of micro-fringe patches has a vertical polarization and at least one other column of micro fringe patches has a horizontal polarization. 4. An antenna, according to claim 1, wherein the patches of micro-fringes within each column are tapered for a pattern configuration in elevation. 5. An antenna, according to claim 1, wherein the beam formation is carried out through an analog beamformer. 6. An antenna, according to claim 1, wherein the beam formation is carried out through a digital beamformer. 7. An antenna, according to claim 1, wherein the beam formation is carried out through a beamforming matrix. 8. An antenna, according to claim 7, wherein the beam-forming matrix is a Butler matrix. 9. An antenna, according to claim 1, wherein each column of the micro-fringe patches is connected to a plurality of power amplifiers. 10. An antenna for a base station in a mobile radiocommunication system, with at least one base station and at least one mobile station, this antenna comprises: a micro-fringe antenna array, which includes a matrix of microchip patches. strips with at least two columns and two rows; a plurality of low noise or interference amplifiers, in which at least one low noise amplifier is connected to each column of the micro-fringe patches; and beamforming elements, connected to each low noise amplifier, to determine the direction and configuration of the narrow antenna lobes, generated by the columns of micro-fringe patches. 11. An antenna, according to claim 10, in which the signals to orthogonal polarized addresses are given with an amplitude relation and a relative phase shift in order to create an elliptical, arbitrary, biasing state. 12. An antenna, according to claim 10, wherein at least one column of the micro-fringe patches has a vertical polarization and at least one other column of the micro fringe patches has a horizontal polarization. 13. An antenna, according to claim 10, wherein the micro-fringe patches, within each column, are tapered for the configuration of the elevation pattern. 14. An antenna, according to claim 10, wherein the beam formation is carried out through an analog beam array. 15. An antenna, according to claim 10, in which the beam formation is carried out through a digital beam formation. 16. An antenna, according to claim 10, wherein the beam formation is carried out through a beamforming matrix. 17. An antenna, according to claim 16, wherein the beam-forming matrix is a Butler matrix. 18. An antenna, according to claim 10, wherein each column of the micro-fringe patches is connected to a plurality of low noise amplifiers. 19. An antenna, according to claim 1, wherein the antenna arrangement is used to both transmit and receive signals. 20. An antenna, according to the claim 19, in which the antenna arrangement has separate columns for transmitting and receiving on the same substrate. 21. An antenna, according to claim 10, wherein the antenna arrangement is used to both transmit and receive signals. 22. An antenna, according to claim 21, wherein the antenna arrangement has separate columns for transmitting and receiving on the same substrate. 23. An antenna for a base station in a mobile radio system, with at least one base station and at least one mobile station, this antenna comprises: a micro-strip antenna arrangement, which includes a matrix of micro-strip patches with at least two columns and two rows; beam forming elements, connected to each column of the antenna arrangement, to determine a direction and configuration of the narrow lobes of the antenna, generated by the columns of the micro-fringe patches; and a plurality of power amplifiers, wherein at least one power amplifier is connected to each output of the beam forming element, to amplify particular lobes of the antenna. 24. An antenna for a this base station in a mobile radio system, with at least one base station and at least one mobile station, this antenna comprises: a micro-strip antenna arrangement, which includes a matrix of micro patches -franks, with at least two columns and two rows; beamforming elements, connected to each column of the antenna array, to determine a direction and configuration of the narrow lobes of the antenna, generated by the columns of the micro-fringe patches; and a plurality of low noise amplifiers, in which at least one low noise amplifier is connected to each output of the beamforming elements, to amplify particular lobes of the antenna.