Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/27—Adaptation for use in or on movable bodies
  • H01Q1/32—Adaptation for use in or on road or rail vehicles
  • H01Q1/325—Adaptation for use in or on road or rail vehicles characterised by the location of the antenna on the vehicle
  • H01Q1/3275—Adaptation for use in or on road or rail vehicles characterised by the location of the antenna on the vehicle mounted on a horizontal surface of the vehicle, e.g. on roof, hood, trunk
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/27—Adaptation for use in or on movable bodies
  • H01Q1/32—Adaptation for use in or on road or rail vehicles
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
  • H01Q5/40—Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
  • H01Q9/04—Resonant antennas

Definitions

• the present invention relates to communication systems. More particularly, it relates to antenna apparatus for receiving signals in communication systems.
• Communication signals that are transmitted over communication systems are subject to many degradations. For example, one common problem communication systems face is fading, wherein the received signal strength falls below an acceptable threshold and the communication signal cannot be properly processed. There are other problems familiar to those skilled in the art.
• One way of overcoming these problems and improving reception of communication signals is to utilize diversity reception wherein at least two spatially separated antennas are used to receive a transmitted communication signal. Then, the received signals can be processed. By selecting the received signal with the best characteristics, reception is improved.
• One drawback to the diversity technique is the need for multiple antennas. This drawback is particularly severe in the mobile communication environment, where multiple holes must be cut in vehicles to support the multiple antennas.
• the present invention provides an antenna useful in receiving diversity signals.
• the antenna includes a first antenna section having two ends. The first end is adapted to be supported on a vehicle with a vertical orientation.
• the antenna also includes a second section having two ends, the first end being connected to the second end of the first antenna section such that the second antenna section is vertically oriented on top of the first antenna section. It is preferred to provide an insulator for electrically isolating the first antenna section from the second antenna section is placed between the two antenna sections.
• Several means of connecting the antenna sections to processing components are contemplated.
• four wires are used.
• a first wire is connected to the ground of the first antenna section, a second wire is connected to the ground of the second antenna section, a third wire is connected to the output of the first antenna section and a fourth wire connected to the output of the second antenna section.
• only three wires are used.
• a first wire is connected to the ground of the first antenna section and to the ground of the second antenna section, a second wire is connected to the output of the first antenna section and a third wire is connected to the output of the second antenna section.
• FIG. 1 illustrates a first embodiment of the linear diversity antenna of the present invention
• FIG. 2 illustrates a second embodiment of the linear diversity antenna of the present invention
• FIG. 3 illustrates an electrical diagram in accordance with a preferred embodiment of the present invention.
• FIG. 4 illustrates the antenna structure of the present invention mounted to a vehicle.
• FIG. 1 illustrates an antenna structure 10 having two sections 1 2 and 14.
• the first antenna section 1 2 includes an inductive element 16 as well as a first end 1 7A and a second end 1 7B.
• the first end 1 7A is adapted to be connected and supported on a vehicle such that the antenna section 12 is vertically oriented. Apparatus and method to connect antennas to vehicles are well known.
• the second antenna section 14 also has an inductive element 20 as well as a first end 21 A and a second end 21 B.
• the first end 21 A is connected to the second end 17B of the first antenna section 1 2 such that the second antenna section 14 is vertically oriented on top of the first antenna section 12.
• the antenna sections 12 and 14 are oriented so that the antenna structure 10 is linear.
• an insulator 24 is optionally placed between the first antenna section 1 2 and the second antenna section 14.
• the insulator 24 electrically isolates the first antenna section 1 2 from the second antenna section 14.
• the insulator 24 may be constructed from any non-conductive material.
• the antenna structure 10 has four wires 25, 26, 27 and 28 that preferably exit from the bottom of the antenna structure 10.
• the wires are four wires 25, 26, 27 and 28 that preferably exit from the bottom of the antenna structure 10.
• the ground wires 26 and 28 are preferably connected to the ground of the first antenna section 1 2 and the second antenna section 14, respectively.
• the ground wires 26 and 28 are also preferably connected to vehicular ground 29.
• the wire 25 is connected to the active element of the first antenna section 12 to provide the signals received by the first antenna section 12 to processing circuitry.
• the wire 27 is connected to the active element of the second antenna section 14 to provide the signals received by the second section 14 to processing circuitry.
• the antenna structure 10 only has three wires exiting the bottom of the structure 10. In this embodiment, the wires 25 and 27 are again connected to the active elements of the first 1 2 and second 14 antenna sections, respectively, to provide the received signals to processing circuitry.
• the wire 28, however, is not used. Instead, the wire 26 is connected to the ground of the first and second antenna sections 12 and 14.
• the antenna structure 30 of FIG. 2 includes a first antenna section 32, a second antenna section 34 and a third antenna section 36.
• Each of the antenna sections 32, 34 and 36 has an active element 38, 42 and 44, respectively.
• insulator elements 46 and 48 are preferably provided between the first 32 and second 34 antenna sections and between the second 34 and third 36 antenna sections, respectively, in order to electrically isolated the antenna sections 32, 34 and 36.
• FIG. 2 illustrates the bottom of the antenna structure 30.
• the wires 50, 51 and 52 are connected to the active elements in the antenna sections 32, 34 and 36, respectively, and provide the signals received by each of these antenna sections to processing circuitry.
• the wire 53 is connected to the ground of each of the antenna sections 32, 34 and 36 and, when connected to a vehicle, is also connected to the vehicular ground 54.
• two wires can be used to connect each antenna section 32, 34 and 36 to the processing circuitry, as described with respect to FIG. 1 .
• FIG. 3 illustrates the circuitry utilized to process the signals received by the antenna structure 30. Of course, the circuitry of FIG. 3 can also be utilized to process the signals received by the antenna structure 10.
• the signals received by the first antenna section 32 are transmitted over the wire 50 to a first RF processing circuit 70.
• the signals received by the second antenna section 34 are transmitted over the wire 51 to a duplexer 72 which then provides the received signals to a second RF processing circuit 74.
• the third antenna section 36 is preferably a Global Positioning Service (GPS) antenna.
• GPS Global Positioning Service
• the signals received by the GPS antenna 36 are transmitted over the wire 52 to a GPS front end receiver and processor 76.
• the first RF processing circuit 70, the second RF processing circuit 74 and the GPS front end processor 76 each receive analog signals from the antenna structure 30 and convert the received signals into digital signals using any of the well known receiving methods. While digital systems are preferred, the antenna of the present invention is not limited to digital systems; rather, it is also useful to process analog signals in which case the processors can be analog processors.
• the antenna sections 32, 34 and 36 can be adapted to receive a variety of communication signals -- primarily by adjusting the length of the antenna sections. In accordance with a preferred embodiment, however, the antenna sections 32 and 34 are adapted to receive communication signals in the same frequency range. Thus, the antenna sections 32 and 34 receive the same communication signals at different points in space. These communication signals are referred to as diversity signals. As previously described, the antenna section 36 is adapted to receive GPS signals.
• the first RF processing circuit 70 and the second RF processing circuit 74 each send the diversity signals to a signal strength processor 78.
• the signal strength processor 78 compares various characteristics of the signals received from the first antenna section 32 to the characteristics of the signals received from the second antenna section 34. Based on the comparison, the signal strength processor 78 determines which signal should be processed and selects that signal for processing. The selected signal is then supplied to the baseband processor 80 for the appropriate baseband processing.
• the central controller 82 controls the operation of the signal strength processor 78 and the baseband processor 80.
• the signal strength processor 78 can be any type of signal strength measuring device. For example, if analog signals are processed any of the well known circuits that measure the signal strength of analog communication signals can be used to determine which diversity signal should be processed by the processor 80. If digital signals are being processed, a microprocessor can be used to determine the strength of the received signal. Additionally, any other measure of signal quality can also be used by the signal strength analyzer 78 to determine which signal to process.
• a transmitter 84 is provided to transmit communication signals.
• the transmitter 84 is connected to the second antenna section 34 through the duplexer 72 and the wire 51 .
• a communication system using the antenna of the present invention can transmit through the antenna as well as receive diversity signals. While either the bottom antenna section 32 or the top antenna section 34 can be used to transmit, it is preferred to use the top antenna section 34.
• the antenna sections 32 and 34 can be used to receive communication signals in different frequency ranges.
• the signal strength processor 78 is presumably not needed since both signals will require processing.
• the antenna structure 30 is connected to a vehicle 90.
• the antenna structure is preferably mounted on top of the roof of the vehicle to provide optimal reception of signals.
• the antenna structure 30 can, however, also be mounted on the trunk as shown or anyplace else on or in the vehicle.
• the circuitry of FIG. 3 is preferably inside a radio terminal mounted inside the vehicle 90 for easy access by the driver of the vehicle 90. It is understood that changes may be made in the above description without departing from the scope of the invention. It is accordingly intended that all matter contained in the above description and in the drawings be interpreted as illustrative rather than limiting.

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Engineering & Computer Science (AREA)
• Remote Sensing (AREA)
• Radio Transmission System (AREA)
• Variable-Direction Aerials And Aerial Arrays (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=24191663

Family Applications (1)

Country Status (5)

Families Citing this family (4)

Citations (2)

Family Cites Families (3)

• 1996
  • 1996-10-25 KR KR1019980702970A patent/KR19990067033A/ko not_active Application Discontinuation
  • 1996-10-25 EP EP96937730A patent/EP0857359A4/de not_active Withdrawn
  • 1996-10-25 WO PCT/US1996/017046 patent/WO1997015961A1/en not_active Application Discontinuation
  • 1996-10-25 AU AU75202/96A patent/AU7520296A/en not_active Abandoned
  • 1996-10-25 JP JP9516772A patent/JPH11514170A/ja active Pending

Patent Citations (2)

Non-Patent Citations (1)

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