Antenna system for use in a wireless communication system

• US 20020053995A1
• Filed: 04/06/2001
• Published: 05/09/2002
• Est. Priority Date: 11/03/2000
• Status: Active Grant

• Current Assignee: KMW Incorporated
• Original Assignee: KMW Incorporated
• Inventors: Kim, Duk-Yong
• Granted Patent: US 6,504,510 B2
• Time in Patent Office: Days
• US Class Current: 343/853
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H01Q 3/32 by mechanical means
• CPC Class Codes: H01Q 3/38 the phase-shifters being digital

Abstract

An antenna system for use in a wireless communication system includes an array of M×N radiating elements for emitting a beam, an input port for providing signals to the array of M×N radiating elements, M number of first phase shifters for steering the-beam on the basis of column by phase shifting the signals from the input port, N number of second phase shifters for steering the beam on the basis of row by phase shifting the signals, N number of switchable dividers for selectively transmitting the signals to a number of transmission lines incorporated into the second phase shifters and M number of combiner/dividers for transmitting the signals from the transmission lines of the second phase shifters to the transmission lines of the first phase shifters. The antenna system can implement a 3-way beam control by utilizing multi-line phase shifters and switchable dividers. Therefore, the antenna system controls cell coverage more flexible than any other prior arts and become friendly with user and the communication environment by utilizing the 3-way beam control. Further, the antenna system can enhance performance and reduce cost by using the multi-line phase shifters.

Claims

1. An antenna system for use in a wireless communication system, comprising:

an array of M×

N radiating elements for emitting a beam, M and N being a positive integer, respectively;

a feeding network for providing a plurality of signals to the array of M×

N radiating elements; and

M number of first phase shifters for steering the beam on the basis of column by phase shifting the signals from the feeding network.

2. The antenna system of claim 1, wherein each of the first phase shifters changes simultaneously a first group of N signals selected from the signals by rotating a dielectric member incorporated into each of the first phase shifters after passing through the first phase shifters.

3. The antenna system of claim 2, further comprising:

a first rotating means for rotating the dielectric members of the first phase shifters.

4. The antenna system of claim 2, wherein each of the first phase shifters includes:

a dielectric member provided with a first and a second portions, wherein a dielectric constant of the first portion is different from that of the second portion; and

N number of transmission lines positioned opposite the dielectric member for transmitting the N signals of the first group, wherein each signal is inputted to one end of a corresponding transmission line and outputted to a corresponding radiating elements after passing therethrough.

5. The antenna system of claim 1, wherein the M and N represent the number of columns and the number of rows, respectively.

6. The antenna system of claim 2, wherein each of the first phase shifters further includes a metal plate provided with a first and a second parts on which the transmission lines are formed.

7. The antenna system of claim 6, wherein M/2 number of transmission lines is formed on the first part and M/2 number of transmission lines is formed on the second part.

8. The antenna system of claim 7, wherein the transmission lines of the first part is arranged in such a way that they are symmetric with respect to those of the second part, whereby if electrical lengths of the transmission lines of the first part are increased to a predetermined value, those of the second part are decreased to the predetermined value.

9. The antenna system of claim 8, wherein if said rotating means rotates the Dielectric member of the first phase shifter, signals have a symmetry in phase plane with respect to its center points after passing through the first phase shifter.

10. The antenna system of claim 1, wherein the feed network includes:

an input port for receiving the plurality of signals; and

M number of combiner/dividers for inputting the signals to each of the transmission lines of the first phase shifter.

11. The antenna system of claim 6, wherein each of the combiner/dividers includes:

a combiner provided with N number of input ports and an output port; and

a divider provided with an input port and N number of output ports.

12. The antenna system of claim 1, further comprising:

N number of second phase shifters for steering the beam on the basis of row by phase shifting the signals from the input port;

13. The antenna system of claim 12, wherein the feed network further includes:

an input port for receiving the plurality of signals;

N number of dividers for transmitting the signals to each of the transmission lines of the second phase shifters; and

M number of combiner/dividers for transmitting the signals to each of the transmission lines of the first phase shifter after passing through the second phase shifters.

14. The antenna system of claim 13, wherein each of the second phase shifters simultaneously changes M number of signals to be phase shifted by rotating a dielectric member incorporated into each of the second phase shifters, the dielectric member being provided with a first an a second portions and a dielectric constant of the first portion being different from that of the second portion.

15. The antenna system of claim 14, further comprising:

a second rotating means for rotating the dielectric members of the second phase shifters.

16. The antenna system of claim 15, wherein each of the second phase shifters further includes:

N number of transmission lines positioned opposite the dielectric member for transmitting the N signals of the first group, wherein each signal is inputted to one end of a corresponding transmission line.

17. The antenna system of claim 16, wherein the second phase shifter further includes a metal plate provided with a first and a second parts on which the transmission lines are formed.

18. The antenna system of claim 10, wherein N/2 number of transmission lines is formed on the first part and N/2 number of transmission lines is formed on the second part.

19. The antenna system of claim 18, wherein the transmission lines of the first part is arranged in such a way that they are symmetric with respect to those of the second part, whereby if electrical lengths of the transmission lines of the first part are increased to a predetermined value, those of the second part are decreased to the predetermined value.

20. The antenna system of claim 12, wherein the feed network further includes:

an input port for receiving the plurality of signals

N number of switchable dividers for selectively transmitting the signals to each of the transmission lines of the second phase shifters; and

M number of combiner/dividers for transmitting the signals to each of the transmission lines of the first phase shifter after passing through the second phase shifters.

21. The antenna system of claim 20, wherein each of the switchable power dividers includes:

an input port for receiving an input signal;

a common node;

N number of first transmission lines;

N number of second transmission lines;

N number of isolation elements disposed between the first and the second transmission lines, wherein each isolation element is electrically connected to a corresponding first and second transmission lines, respectively;

N number of output ports for outputting N number of output signals, each of the output ports being connected to a portion between a corresponding isolation element and a first or a second transmission line;

N number of fourth switches for selectively switching the input signal to the first transmission lines; and

N number of fifth switches for selectively switching the common node to the second transmission lines based on the first switches.

22. The antenna system of claim 21, wherein M is 4 and N is 8 for applying to IMT-2000.

23. The antenna system of claim 20, further comprising:

a beam control board for generating a control signal to control the switchable divider, the first and the second rotating means.

25. The antenna system of claim 24, wherein the first phase shifter includes:

a dielectric member provided with a first and a second portions, wherein a dielectric constant of the first portion is different from that of the second portion; and

N number of transmission lines positioned opposite the dielectric member for transmitting the N signals of the first group, wherein each signal is inputted to one end of a corresponding transmission line and outputted to a corresponding radiating elements after passing therethrough.

26. The antenna system of claim 24, further comprising:

means for rotating the dielectric member.

27. The antenna system of claim 24, wherein the radiators are arranged in such a way that they form a column.

28. The antenna system of claim 24, wherein the radiators are arranged in such a way that they form a row.

30. The antenna system of claim 29, wherein the switchable power divider includes:

an input port for receiving the signal;

a common node;

N number of first transmission lines;

N number of second transmission lines;

N number of isolation elements disposed between the first and the second transmission lines, wherein each isolation element is electrically connected to a corresponding first and second transmission lines, respectively;

N number of output ports for outputting N number of output signals, each of the output ports being connected to a portion between a corresponding isolation element and a first or a second transmission line;

N number of fourth switches for selectively switching the input signal to the first transmission lines; and

N number of fifth switches for selectively switching the common node to the second transmission lines based on the first switches.

31. The antenna system of claim 30, wherein a width of the beam is controlled by changing N of the switchable divider.

24. An antenna system for use in a wireless communication system, comprising:

an array of N radiating elements for emitting a beam, N being a positive integer;

a feeding network for providing a plurality of signals to the array of N radiating elements; and

a phase shifter for steering the beam by simultaneously phase shifting the signals from the feeding network.

29. An antenna system for use in a wireless communication system, comprising:

an array of N radiating elements for emitting a beam, N being a positive integer;

a switchable divider for selectively providing a signal to the array of N radiating elements; and

a phase shifter for steering the beam by simultaneously phase shifting the signals from the feeding network.