| 摘要 |
<p>A steerable null antenna processor system is described for receiving desired wave energy signals from at least one angular region of space, and for suppressing interfering signals from at least one other angular region. The system includes at least first and second antenna elements. Nulling means are coupled between the antenna elements and a common port to supply signals to said common port, and have phase means and amplitude means, both adjustable in incremental steps. The nulling means also has control inputs, responsive to control signals to adjust respectively the phase and amplitude values of the nulling means. The amplitude means is a variable ratio combiner having a quadrature hybrid, a sum-difference hybrid, and two adjustable delay lines between said hybrids. A digital controller means is also included having clock means, sample storage means, comparison means, feedback input means, and phase and amplitude memory means having connections to control inputs of the phase and amplitude means respectively. Apparatus between the common port and the feedback input means supplies feedback signals containing a representation of the interfering signal at the common port. Clock signals provide successive cycles. The comparison means operates during each cycle to compare a feedback signal from the feedback input means to a previous sample thereof stored in said sample storage means, to indicate improvement. It also supplies the control signals via the memory means to the nulling means to make adjustments for steering at least one null to the interfering signals. Preferably the nulling means is operable selectively for one of receiving and transmitting, and the phase and amplitude means are up-down counters, in which values are more preferably stored as binary numbers. Still more preferably, second nulling means are provided coupled to third and fourth antenna elements.</p> |
