Dual Circularly Polarized Shared Aperture Reflector Antenna for S/Ka-Band Telemetry Tracking

This manuscript reports the development of a shared aperture dual circularly polarized (CP) reflector antenna with wide band tracking at S-/Ka-band. It operates in cassegrain mode at Ka-band and in prime-focus configuration at S-band. A frequency selective subreflector (FSSR) isolates the two feeds, allows S-band transmission, and reflects the Kaband signal. It yields an impedance bandwidth ≥ 25% at Sband with an isolation ≥ 24 dB. At Ka-band, the bandwidth is ≥ 12.5% with an isolation ≥ 30 dB. Monopulse tracking is established over ≥ 15% bandwidth at S-band and ≥ 8% at Ka-band. It reveals a gain of 49.5 dBiC at the Ka-band and 28.4 dBiC at the S-band. The antenna demonstrates improved features and measured results are enhanced compared to the earlier reported investigations. The angular field-of-view (FOV) of the antenna for tracking is ≥ 6.2° at S-band and is ≥ 0.5° at Ka-band.