Circularly Polarized Antenna Design and Applications

Circularly polarised (CP) antennas radiate electromagnetic waves whose electric field rotates in a helical fashion, offering robustness against orientation mismatch and multipath fading. Design approaches typically employ orthogonal radiating elements excited in quadrature phase, achievable through sequentially rotated patches, truncated corners, slot perturbations or hybrid couplers. Key performance metrics include impedance bandwidth, axial‐ratio bandwidth (the range over which the polarisation purity remains within specified limits) and gain stability. Recent advances have focused on uniplanar and compact configurations, integration of energy‐harvesting elements, and enhancement of beamwidth for wide‐area coverage. Applications span global navigation satellite systems, broadband wireless links, CubeSat communications, Internet of Space Things, radar and RFID. Emerging fabrication techniques and novel feeding networks enable ultra‐wideband operation while maintaining low profile, high isolation and wide axial‐ratio beamwidth, meeting demanding requirements in avionics, maritime, mobile handsets and autonomous platforms.

Research from Nature Portfolio

A uniplanar crossed‐dipole design printed on a single dielectric substrate has demonstrated exceptionally wide CP performance. Corner‐cut fat dipole arms, arranged orthogonally and linked by a bent stripline, excite two near‐degenerate modes in quadrature. A microstrip‐to‐parallel‐stripline tapered balun minimises leakage and supports an impedance bandwidth of 113% (2.53–9.14 GHz) and a 3 dB axial‐ratio bandwidth of 98% (2.65–7.75 GHz). Peak gain reaches 3.7 dBic, and the compact 45 × 45 × 0.508 mm3 form factor suits handheld and on‐board systems.

Circularly Polarized Antenna Design and Applications publication trend

The graph below shows the total number of articles in circularly polarized antenna design and applications across all publications each year (not limited to Nature Index journals).

Technical terms

Circular polarisation: Electromagnetic wave with electric field vector rotating at constant magnitude in orthogonal planes.

Axial ratio (AR): Ratio of major to minor axes of polarization ellipse; 1 dB–3 dB AR denotes near‐ideal circularity.

Impedance bandwidth: Frequency range over which input reflection coefficient meets specified return‐loss criteria (e.g. |S11| < –10 dB).

Microstrip patch antenna: Planar radiating element printed on a dielectric substrate, often used for compact CP designs.

Balun: Device that converts unbalanced feed (coaxial) to balanced feed (dipole or stripline) while maintaining phase relationships.

Dipole mode: Fundamental radiation mode of two opposing currents producing figure‐eight field pattern; magneto‐electric dipole antennas exploit both electric and magnetic dipole pairs.

References

1. Design of a broadband circularly polarised uniplanar crossed-dipole antenna. Scientific Reports (2024).
2. Hexagonal-Triangular Combinatorial Structure Based Dual-Band Circularly Polarized Patch Antenna for GAGAN Receivers. IEEE Access (2023).
3. A Single-Fed Wideband Circularly Polarized Cross-Fed Cavity-Less Magneto-Electric Dipole Antenna. Sensors (2023).
4. Low-Profile Wideband Solar-Cell-Integrated Circularly Polarized CubeSat Antenna for the Internet of Space Things. IEEE Access (2022).