Phase weighted adaptive processor
First Claim
1. An adaptive processor system of the type employed to eliminate undesired signals, comprising:
- a first signal path having an undesirable reference signal thereon,a second signal path having an attenuated and delayed replica of said undesired reference signal thereon, which is processed to track said reference signal,a phase tracking feedback path connected in parallel with said second signal path and adapted to shift the phase of said attenuated and delayed replica of said undesired reference signal in said second path to equal the phase of said reference signal,said phase tracking feedback path comprising therein, a voltage controlled oscillator and a delay coupled to the output of said voltage controlled oscillator,the output of said delay being phase shifted as a function of the frequency of said voltage controlled oscillator to provide a phase shifted oscillator output signal, andmeans in said second signal path for coupling said oscillator output signal and said phase shifted oscillator output signal to the attenuated and delayed replica of said reference signal to provide a phase shifted attenuated and delayed replica signal in phase with said reference signal.
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Accused Products
Abstract
Undesirable signals which are similar to desirable signals occur in transmitter-receiver systems, phased array antenna systems and null or steering antenna systems and are eliminated by a novel adaptive processor. The undesired signal is electronically cancelled by causing the weak undesired replica signal to track the stronger undesired reference signal. The circuitry structure employs a phase tracking loop which generates a phase tracking error signal. The phase tracking error signal is applied to a voltage controlled oscillator and a fixed delay element in the phase tracking loop path. The phase tracking loop is coupled to the weak signal path to shift the phase of the weak undesired replica signal so that it is in phase with the stronger undesired reference signal and may be electronically cancelled. The system may be employed to eliminate undesired signals and leave weak desired signals uneffected and easily detectable.
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Citations
13 Claims
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1. An adaptive processor system of the type employed to eliminate undesired signals, comprising:
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a first signal path having an undesirable reference signal thereon, a second signal path having an attenuated and delayed replica of said undesired reference signal thereon, which is processed to track said reference signal, a phase tracking feedback path connected in parallel with said second signal path and adapted to shift the phase of said attenuated and delayed replica of said undesired reference signal in said second path to equal the phase of said reference signal, said phase tracking feedback path comprising therein, a voltage controlled oscillator and a delay coupled to the output of said voltage controlled oscillator, the output of said delay being phase shifted as a function of the frequency of said voltage controlled oscillator to provide a phase shifted oscillator output signal, and means in said second signal path for coupling said oscillator output signal and said phase shifted oscillator output signal to the attenuated and delayed replica of said reference signal to provide a phase shifted attenuated and delayed replica signal in phase with said reference signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification