Signal routing system

• US 5,048,116 A
• Filed: 05/24/1989
• Issued: 09/10/1991
• Est. Priority Date: 05/24/1989
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Schaeffer, Dennis R.
• Primary Examiner(s): KUNTZ, CURTIS A
• Application Number:
  US07/356,160
• Time in Patent Office: 839 Days
• Field of Search: 455/33, 455/67, 455/134, 455/272, 455/275, 455/277, 455/51, 455/103, 455/56, 379/59, 379/60, 379/62, 370/84
• US Class Current: 455/561
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 21/06 Arrays of individually energised antenna units similarly polarised and spaced apart
• CPC Class Codes: H01Q 21/205 providing an omnidirectional coverage turnstile aerials H01Q21/26
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A signal routing system for use in cellular RF communications systems wherein a signal can be routed to different antennas, effectively switching transmitters between antennas. The switching is accomplished by placing a frequency responsive device between a transmitter and each antenna. The transmitter is then coupled to an antenna through the frequency responsive device that has a resonant frequency equal to the transmitter'"'"'s frequency. If the transmitter changes frequency, it will be switched to the appropriate antenna through the corresponding frequency responsive device. This system permits a sector of a cell to increase the number of frequencies in that sector to handle increased mobile traffic loads.

Claims

1. A signal routing system for dynamically switching frequencies among a plurality of antennas of a cell, each antenna radiating into a different sector of the cell, the system comprising:

a) a signal transmission source for generating a plurality of signals;

b) a plurality of communication paths, coupled to the signal transmission source, for conducting the plurality of signals; and

c) a plurality of frequency responsive means, each frequency responsive means coupled to a different communication path, for allowing a first signal of the plurality of signals to be supported by a particular communication path only when the first signal has a predetermined frequency.

2. The signal routing system of claim 1 wherein the signal transmission source is a transmitter with a synthesizer capable of changing frequency within a predetermined time.

3. The signal routing system of claim 1 wherein the signal transmission source controls routing of the plurality of signals.

4. The signal routing system of claim 1 wherein the frequency responsive means includes a tuned resonant cavity responsive to a predetermined frequency.

5. The signal routing system of claim 1 wherein at least one of the plurality of communication paths is a phasing line.

6. A signal routing system for dynamically switching frequencies among a plurality of antennas of a cell, each antenna radiating into a different sector of the cell, the system comprising:

a) a plurality of signal transmission sources for generating a plurality of signals;

b) a plurality of communication paths, coupled to the plurality of signal transmission sources, for conducting the plurality of signals; and

c) a plurality of frequency responsive means, each frequency responsive means coupled to a different communication path, for allowing a first signal of the plurality of signals to be supported by a particular communication path only when the first signal is of a predetermined frequency.

7. The signal routing system of claim 6 wherein the signal transmission sources control routing of the signals.

8. The signal routing system of claim 6 wherein the frequency responsive means includes tuned resonant cavities.

9. The signal routing system of claim 6 wherein at least one of the plurality of communication paths is a phasing line.

10. The signal routing system of claim 6 wherein the signal transmission sources are transmitters with synthesizers capable of changing frequency within a predetermined time.

11. The signal routing system of claim 10 wherein the transmitters are coupled to the antennas by tuned resonant cavities.

12. The signal routing system of claim 6 wherein the plurality of antennas forms an array, a plurality of subsets of the antenna array form a plurality of subarrays, and the plurality of signal transmission sources are coupled to the antennas in a configuration such that each signal transmission source in a first subarray is unable to be coupled to antennas in other subarrays.

13. A signal routing device for routing frequencies, generated by a plurality of variable frequency signal transmission sources, between a plurality of antennas of an antenna array, a subset of the plurality of antennas forming a subarray of the antenna array, a subset of the plurality of variable frequency signal transmission sources being able to transmit from a first subarray and not from a second subarray, the device comprising:

a) a plurality of communication paths, coupling the plurality of variable frequency signal transmission sources to the plurality of antennas, for transmitting the plurality of frequencies; and

b) a plurality of frequency responsive means, each means tuned to a predetermined frequency and coupled to a separate communication path of the plurality of communication paths, the means allowing a frequency to be supported by a communication path when the frequency is the same as the predetermined frequency.

14. A method for routing signals to a plurality of antennas of a cell, the signals generated by at least one variable frequency signal transmission source, the at least one variable frequency signal transmission source coupled to the plurality of antennas by a plurality of communication paths, each communication path having a frequency responsive means tuned to a different predetermined frequency, the cell providing communication capability to mobile traffic, the method comprising the steps of:

a) generating a signal of a first predetermined frequency for transmission by a first antenna, the first antenna coupled to a first frequency responsive means tuned to the first predetermined frequency; and

b) in response to the mobile traffic, generating a signal of a second predetermined frequency for transmission by a second antenna, the second antenna coupled to a second frequency responsive means tuned to the second predetermined frequency.