An S-/Ka-Band Shared Aperture Tracking Reflector Antenna With Polarization Diversity

A dual-band dual-polarized tracking reflector design approach has been explored, and successfully demonstrated the S- and Ka-band tracking with enhanced performance. The antenna works in Cassegrain mode at Ka-band and the prime focus configuration at S-band. A frequency selective subreflector isolates the two feeds, permits S-band transmission, and reflects the Ka-band signal. The antenna is dual linearly polarized at S-band and dual circularly polarized at Ka-band. It capitulates an impedance bandwidth wider than 23.9% with isolation superior to 24 dB at the S-band ports. At the Ka-band, it also displays an axial ratio ≤3 dB with isolation above 23 dB over the entire operating bandwidth of ≥12.4%. Monopulse tracking bandwidths of ≈13% at the S-band and ≈8% at the Ka-band have been established. It reveals a gain of 53 dBi at Ka-band and 29 dBi at S-band. The antenna demonstrates improved features, and measured results are enhanced compared to the earlier reported investigations.