Single feed dual band circularly polarized stub loaded tunable microstrip patch antenna

A single feed dual band circularly polarized stub loaded tunable microstrip patch antenna operating at S-band has been designed and fabricated. The antenna is designed for center frequencies of 2.23 GHz and 3.85 GHz. Paper also present two more designs to make the antenna compact without much alteration in the results. The proposed antenna configuration is designed using IE3D simulation software. Antenna is designed on Arlon substrate having dielectric constant (ε_r) = 2.55, loss tangent (tan δ) = 0.001 and thickness = 1.6 mm. An Axial ratio of less than 2 dB is achieved at both the frequencies. Simulated and measured results are in good agreement.