Null steering apparatus for a multiple antenna array on an AM receiver

Claim 2

In a multiple antenna array, null steering apparatus for reception of a carrier signal having modulated thereon an AM signal and a relatively low level identifier signal substantially in phase quadrature with the AM signal, said null steering apparatus comprising: a. feedback means associated with each antenna in said array for adjusting the amplitude and phase of signals therein so that unwanted signals from the array are cancelled; b. reference signal producing means coupled to said feedback means for picking off the identifier signal and utilizing the identifier signal to generate a reference signal having the same frequency and phase as the carrier signal; and c. compensating means coupled to said feedback means for utilizing the reference signal to form a lobe in the antenna pattern in the direction of the carrier having the AM signal thereon.

Claim 3

In a multiple antenna array, null steering apparatus for reception of a carrier signal having modulated thereon an AM signal and a relatively low level identifier signal substantially in phase quadrature with the carrier signal, said null steering apparatus comprising: a. feedback means associated with each antenna in said array for separating signals coupled from the antenna, representable as phasors, into in-phase and quadrature components and adjusting the in-phase and quadrature components to alter the amplitude and phase of the phasors so that unwanted signals from the array are cancelled; b. reference signal producing means coupled to said feedback means for picking off the identifier signal and utilizing the identifier signal to generate a reference signal having the same frequency and phase as the carrier signal; and c. compensating means coupled to said feedback means for utilizing the reference signal to form a lobe in the antenna pattern in the direction of the carrier having the AM signal thereon.

Claim 4

In a multiple antenna array, null steering apparatus for reception of a carrier signal having modulated thereon an AM signal and a relatively low level identifier signal substantially in phase quadrature with the carrier signal, said null steering apparatus comprising: a. feedback means associated with each antenna in said array for separating signals coupled from the antenna, representable as phasors, into in-phase and quadrature components and adjusting the in-phase and quadrature components to alter the amplitude and phase of the phasors so that unwanted signals from the array are cancelled; b. reference signal producing means coupled to said feedback means for picking off the identifier signal and utilizing the identifier signal to generate a reference signal having the same frequency and phase as the carrier signal; and c. compensating means coupled to said feedback means for utilizing the reference signal to form a lobe in the antenna pattern in the direction of the carrier having the AM signal thereon.

Claim 5

Null steering apparatus as claimed in claim 2 wherein the identifier signal is a PN code signal.

Claim 6

In a multiple antenna array, null steering apparatus for reception of a carrier signal having modulated thereon an AM signal and a relatively low level PN code signal substantially in phase quadrature with the carrier signal, said null steering apparatus comprising: a. feedback means associated with each antenna in said array for separating signals from the antenna, representable as a phasor, into in-phase and quadrature components and adjusting the in-phase and quadrature components to alter the amplitude and phase of the phasor so that unwanted signals from the array are cancelled; b. PN decoder means coupled to said feedback means for picking off the PN code signal and converting the PN code signal to a CW signal; c. narrowband filter means connected to said PN decoder means for receiving and passing the CW signal; d. amplifier means connected to said filter means for receiving the CW signal therefrom and shifting the phase thereof, in conjunction with said filter means, substantially 90° into phase into the carrier; and e. compensating means coupled to said feedback means for utilizing the phase shifted CW signal to form a lobe in the antenna pattern in the direction of the carrier having the AM signal thereon.

Claim 7

In a multiple antenna array, null steering apparatus for reception of a carrier signal having modulated thereon an AM signal and a relatively low level PN code signal substantially in phase quadrature with the carrier signal, said null steering apparatus comprising: a. feedback means associated with each antenna in said array for separating signals from the antenna, representable as a phasor, into in-phase and quadrature components and adjusting the in-phase and quadrature components to alter the amplitude and phase of the phasor so that unwanted signals from the array are cancelled; b. PN decoder means coupled to said feedback means for picking off the PN code signal and converting the PN code signal to a CW signal; c. narrowband filter means connected to said PN decoder means for receiving and passing the CW signal; d. amplifier means connected to said filter means for receiving the CW signal therefrom and shifting the phase thereof, in conjunction with said filter means, substantially 90° into phase into the carrier; and e. compensating means coupled to said feedback means for utilizing the phase shifted CW signal to form a lobe in the antenna pattern in the direction of the carrier having the AM signal thereon.

Claim 8

Null steering apparatus as claimed in claim 4 wherein the PN decoder means includes a mixer having one input connected to receive the PN code signal from the feedback means and a second input connected to have applied thereto a PN code generated at the null steering apparatus for removing the PN code from the carrier and leaving only a carrier shifted from the AM carrier by 90°.

Claim 9

In a communications system including a transmitter for transmitting a carrier signal, having modulated thereon an AM signal and a relatively low level PN code signal substantially in phase quadrature with the carrier signal, and a receiver having a multiple antenna array attached thereto, a method of null steering the array comprising the steps of: a. separating signals from each antenna, representable as a phasor, into in-phase and quadrature components and adjusting the amplitude of the components to vary the amplitude and phase of the phasors so that unwanted signals from the array, are cancelled; b. separating the PN code signal from the AM signal and decoding the PN code signal to provide a CW signal substantially in phase quadrature with the transmitted carrier signal; c. shifting the phase of the CW signal substantially 90° into phase with the transmitted carrier signal; and d. utilizing the phase shifted CW signal in adjusting the amplitude of the components to form a lobe in the antenna pattern in the direction of the carrier signal having the AM signal thereon.

Claim 10

In a communications system including a transmitter for transmitting a carrier signal, having modulated thereon an AM signal and a relatively low level PN code signal substantially in phase quadrature with the carrier signal, and a receiver having a multiple antenna array attached thereto, a method of null steering the array comprising the steps of: a. separating signals from each antenna, representable as a phasor, into in-phase and quadrature components and adjusting the amplitude of the components to vary the amplitude and phase of the phasors so that unwanted signals from the array, are cancelled; b. separating the PN code signal from the AM signal and decoding the PN code signal to provide a CW signal substantially in phase quadrature with the transmitted carrier signal; c. shifting the phase of the CW signal substantially 90° into phase with the transmitted carrier signal; and d. utilizing the phase shifted CW signal in adjusting the amplitude of the components to form a lobe in the antenna pattern in the direction of the carrier signal having the AM signal thereon.

Claim 11

In a communication system including a transmitter for transmitting a carrier signal having modulated thereon an AM signal and a receiver having a multiple antenna array attached thereto, a method of null steering the array comprising the steps of: a. transmitting an identifier signal with the AM signal, which identifier includes a relatively low level signal modulating the carrier signal substantially in phase quadrature with the carrier signal; b. separating signals from each antenna, representable as a phasor, into in-phase and quadrature components and adjusting the amplitude of the components to vary the amplitude and phase of the phasors so that unwanted signals from the array are cancelled; c. separating the identifier signal from the AM signal and utilizing the identifier signal to generate a reference signal having the same frequency and phase as the carrier signal; and d. utilizing the reference signal in adjusting the amplitude of the components to form a lobe in the antenna pattern in the direction of the carrier signal having the AM signal thereon.

Claim 12

In a communication system including a transmitter for transmitting a carrier signal having modulated thereon an AM signal and a receiver having a multiple antenna array attached thereto, a method of null steering the array comprising the steps of: a. transmitting an identifier signal with the AM signal, which identifier includes a relatively low level signal modulating the carrier signal substantially in phase quadrature with the carrier signal; b. separating signals from each antenna, representable as a phasor, into in-phase and quadrature components and adjusting the amplitude of the components to vary the amplitude and phase of the phasors so that unwanted signals from the array are cancelled; c. separating the identifier signal from the AM signal and utilizing the identifier signal to generate a reference signal having the same frequency and phase as the carrier signal; and d. utilizing the reference signal in adjusting the amplitude of the components to form a lobe in the antenna pattern in the direction of the carrier signal having the AM signal thereon.