Dual-band dual-polarised microstrip antenna with improved inter-port isolation

This Letter presents the development of a dual linearly polarised microstrip antenna for S- and C-band with improved isolation and bandwidth. The antenna is dual linearly polarised at each of the bands. The S-band patch is proximity coupled to two orthogonal feed lines, whereas the C-band patches are aperture coupled to other two mutually orthogonal feed lines. The antenna results in an impedance bandwidth ≥ 3.65% with an isolation ≥ 26 dB at the S-band ports. At the C-band ports, it also displays an isolation ≥ 45 dB over the entire operating bandwidth of ≥ 21%. All these results are improved compared to the earlier reported investigations.