Dual‐band dual sense microstrip antenna with improved characteristics

The development of a dual polarised microstrip antenna for S‐ and C‐band with improved characteristics is presented. It is dual linearly polarised at S‐band and dual circularly polarised at C‐band. Two orthogonal feeds have been conceived for proximity coupling at S‐band. The other two composite feeds are aperture coupled at C‐band. These generate left‐hand and right‐hand circular polarisations exclusively. The antenna reveals 3.5% or more impedance bandwidth at the S‐band ports with an isolation better than 22 dB (the best isolation is ≈31.5 dB at the band‐centre). It yields >21.2% impedance bandwidth and about 10.2% axial‐ratio bandwidth at each of the C‐band ports, both being improved compared to the earlier reports. Achieved isolation between the C‐band ports is better than 18.5 dB (≈23.5 dB at the centre of the working band).