SIGNAL PROCESSOR FOR ELIMINATION OF SIDELOBE RESPONSES AND GENERATION OF ERROR SIGNALS

Abstract

A signal processor eliminates sidelobe response from signals produced by a spaced antenna array that forms a single beam using spatial frequencies. The signal processor also produces error signals. The signal processor uses a phase coherent local oscillator to simultaneously convert the wavefront signal from each element of the antenna array to three different first intermediate frequency signals IF. The first IF signals of each element are cross-correlated with the first IF signals from each of the other array elements to form the signals containing sampled spatial frequency components IF2. Cross-correlating a second time using the sampled spatial frequencies as inputs produces signals containing derived spatial frequency components IF3. The signals containing derived spatial frequency components are synchronously detected (phase compared) and summed to provide a single beam output signal. The summed output signal passes through a linear peak detector biased to the peak of the largest even sidelobe such that only signals within the main beam and above the bias level appear in the final output. The derived spatial frequencies are also phase shifted by 90° and detected signals containing "imaginary" spatial frequency components. The sum of the signals with imaginary components represents an error pattern. Also, summation of the signals with imaginary components for the odd order spatial frequency harmonics produces an error signal approximating a signum function of the angle of incidence of the incoming wavefront.

Source: Google Patents

35 USC §181 Secrecy Order

Inventor

• 1JULIUS A. KAISER

Technology Domains

Click a domain to browse all patents in this category.