Patent ID: 7038620

Claim:
In a phased array, phase-amplitude monopulse radar system, a radar subsystem comprising: a phased array antenna including a plurality of substantially horizontal rows of radiating elements disposed in phased-relationship to one another; said plurality of substantially horizontal rows of radiating elements being maintained in a predetermined relationship along a vertical axis with a top and bottom horizontal row, each of said horizontal rows having a horizontal perpendicular sensitivity direction in a horizontal plane making a horizontal acute angle with respect to a boresight line; feed means for coupling radiation to and from said phased array antenna, said feed means including sum and difference feed means for coupling respective sum and difference monopulse information from said phased array antenna to a signal processing means for interpreting radar return signals; and a plurality of phase shift means connected directly to said rows of radiating elements for controllably modifying the phase of electromagnetic energy coupled from said feed means to each of said horizontal rows of said phased array antenna; characterized in that: each of said top and bottom rows of said phased array antenna is set with a corresponding horizontal sensitivity direction on opposite sides of said boresight line and forming a diverging acute angle with respect thereto; at least two intermediate rows of said plurality of horizontal rows are set with monotonically varying intermediate angles of said horizontal sensitivity directions, whereby said difference monopulse information contains both elevation and azimuthal difference information.