A Compact CRLH-TL Loaded Circularly Polarized Antenna with Improved 3-dB Axial-Ratio Beamwidth for Small Satellite Applications

This work presents the design and analysis of a compact composite right/left-handed transmission line (CRLHTL) loaded antenna useful for small satellite applications at 4.2 GHz. The antenna is comprised of two pairs of CRLH-TL radiators orthogonally placed in a rotating fashion for obtaining circular polarization (CP). The novelty behind the intended CP antenna design is the generation of improved 3-dB AR beamwidth. Using the above concept a miniaturized antenna of size 30 × 30 × 1.27 mm
³
is designed and fabricated. The intended antenna provides an improved CP beamwidth (ARBW<; 3dB) and gain greater than 1.42 dBic for theta = ±60
⁰
and for all phi values (phi = 0
⁰
to 360
⁰
) at 4.2 GHz. The antenna provides S
₁₁
bandwidth of 2.44% (4.13-4.232 GHz) and axial ratio bandwidth of 1.19% (4.17-4.22 GHz). Also, the antenna provides a maximum gain of 5.46 dBic and efficiency >93% by maintaining the antenna compactness and low profile (0.017λ
₀
). Hence the proposed CRLH-TL loaded antenna is suitable for work in modern small satellite applications.