摘要 |
<p>A wide band, single aperture antenna system (70) that provides simultaneous detection of both RHCP and LHCP signals. The antenna system (70) includes a multiple arm spiral antenna (10) that has spiral arm elements (12, 14, 16, 18) with no sharp transitions. To simultaneously both RHCP and LHCP sensitivity, an antenna feed is connected to both the center end and the outer end of each of the antenna arm elements (12, 14, 16, 18). A separate N-port transformer (74, 78) is connected to both the end feed and the center feed for all of the arms (12, 14, 16, 18) to provide impedance matching and cross-polarization compensation. An NXN port modeformer (76, 80) is connected to the N-port transformers (74, 78) to separate the various modes. The modeformers (76,80) separate the LHCP and RHCP modes to provide an accurate AoA estimation.</p> |