ANTENNA ARRAY PHASE QUADRATURE TRACKING SYSTEM

• US 3,568,197 A
• Filed: 12/05/1969
• Issued: 03/02/1971
• Est. Priority Date: 12/05/1969
• Status: Expired due to Term

• Current Assignee: Cubley Harold Dean
• Original Assignee: Cubley Harold Dean
• Inventors: CUBLEY HAROLD DEAN
• Application Number:
  US04/882,577
• Time in Patent Office: 452 Days
• US Class Current: 342/354
• CPC Class Codes: H01P 1/15 by semiconductor devices
• CPC Class Codes: H04B 7/0868 Hybrid systems, i.e. switching and combining

Abstract

The system input signals on two separate antenna elements in an antenna array are combined to form two processed signals with one such signal representing the absolute value of the sum of the two antenna signals and the other representing the absolute value of the difference of the signals. The two processed signals are time multiplexed through a radiofrequency switch operating at 10millisecond intervals to form a single input signal to a receiver which in turn detects amplitude modulation in the multiplexed signal and forms an amplitude dependent signal to control a variable phase shifter circuit. The latter circuit automatically alters the relative phase between the two antenna signals whenever any amplitude modulation exists in the multiplex signal. Relative phase shift of the antenna signals stops when the absolute value of the two processed output signals are equal to each other which occurs only when the two antenna signals are in phase quadrature. The described procedure may be employed for any number of antennas connected in parallel to provide substantially omnidirectional antenna coverage and the time multiplexing and signal processing operations may be performed with stripline circuitry and techniques. For transmitting, a phase detector is employed to detect the phase modulation in the received multiplexed signal to establish and switch to the antenna in the array which will provide the greatest system gain for use while transmitting. The invention described herein was made by an employee of the United States Government and may be manufactured and used by or for the government for governmental purposes without the payment of any royalties thereon or therefor.

Claims

1. An antenna system for use with a plurality of antenna elements comprising:

a. Processing means for combining two antenna signals received from two of said plurality of antennas to provide a first processed signal representing the sum of said two antenna signals and a second processed signal representing the difference of said two antenna signals;

b. Amplitude detecting means connected with said first and second processed signals for detecting an amplitude difference between said first and second processed signals and for forming a first control signal representing the presence or absence of said amplitude difference;

c. Phase-shifting means controllable by said first control signal for changing the phase difference between said two antenna signals;

d. Phase-detecting means for detecting a phase difference between said first and second processed signals and for forming a second control signal based on said phase difference indicating which of said two antenna signals has the greatest amplitude; and

e. Automatic switching means controllable by said second control signal for switching a transmitter to the antenna having the maximum amplitude antenna signal.

2. An antenna system for use with a plurality of antenna elements comprising:

a. Processing means for combining two antenna signals received from two of said plurality of antennas to provide a first processed signal representing the sum of said two antenna signals and a second processed signal representing the difference of said two antenna signals;

b. Amplitude-detecting means connected with said first and second processed signals for detecting an amplitude difference between said first and second processed signals and for forming a first control signal representing the presence or absence of said amplitude difference;

c. Phase-shifting means controllable by said first control signal for changing the phase difference between said two antenna signals, said phase-shifting means including means for altering the phase difference between said two antenna signals until said two processed signals have the same amplitude;

d. Phase-detecting means for detecting a phase difference between said first and second processed signals and for forming a second control signal based on said phase difference and which of said two antenna signals has the greatest amplitude; and

e. Automatic switching means controllable by said second control signal for switching a transmitter to the antenna having the maximum amplitude antenna signal.

3. The antenna system as defined in claim 2 further including multiplexing means for time multiplexing said first and second processed signals to form a multiplexed signal which is alternately said first and then said second processed signals.

4. The antenna system as deFined in claim 3 further including a transceiver connected with said antenna system for receiving and transmitting through said antennas.

5. An antenna system for use with a plurality of antenna elements comprising:

a. Processing means for combining two antenna signals received from two of said plurality of antennas to provide a first processed signal representing the sum of said two antenna signals and a second processed signal representing the difference of said two antenna signals;

b. Amplitude-detecting means connected with said first and second processed signals for detecting an amplitude difference between said first and second processed signals and for forming a first control signal representing the presence or absence of said amplitude difference;

c. Phase-shifting means controllable by said first control signal for changing the phase difference between said two antenna signals;

d. A stripline circuit configuration having a plurality of conducting branches;

e. A first conducting branch of said strip line circuit connected to one of said two antennas;

f. A second conducting branch of said strip line circuit connected between the other of said two antennas and said first branch to form a signal-combining junction with said first branch;

g. Said first branch including two selectively operable conducting paths with one of said paths being a half wavelength longer than said other path whereby said antenna signal traveling over said shorter path is 180* out of phase with said signal traveling over said longer path at said junction; and

h. Means for alternately operating said first and second conducting paths to form and time multiplex said two processed signals at said junction.

6. The antenna system as defined in claim 5 wherein said stripline circuit configuration further includes means for connecting a transmitter to one of said two antennas and means for isolating signals received by said antenna from said transmitter.

7. The antenna system as defined in claim 6 further including:

a. Phase-detecting means for detecting a phase difference between said first and second processed signals and for forming a second control signal based on said phase difference and which of said two antenna signals has the greatest amplitude; and

b. Automatic switching means controllable by said second control signal for switching a transmitter to the antenna having the maximum amplitude antenna signal.

8. The antenna system as defined in claim 4 wherein said processing means includes:

a. A stripline circuit configuration having a plurality of conducting branches;

b. A first conducting branch of said stripline circuit connected to one of said two antennas;

c. A second conducting branch of said stripline circuit connected between the other of said two antennas and said first branch to form a signal-combining junction with said first branch;

d. Said first branch including two selectively operable conducting paths with one of said paths being a half wavelength longer than said other path whereby said antenna signal traveling over said shorter path is 180* out of phase with said signal traveling over said longer path at said junction; and

e. Means for alternately operating said first and second conducting paths to form and time multiplex said two processed signals at said junction.

9. The antenna system as defined in claim 8 wherein said stripline circuit configuration further includes means for connecting a transmitter to one of said two antennas and means for isolating signals received by said antenna from said transmitter.