Wide-Band Wide-Beam Circularly-Polarized Slot-Coupled Antenna for Wide-Angle Beam Scanning Arrays

Area of Science:

• Antennas and Propagation
• Electromagnetics
• Microwave Engineering

Background:

• Wide-angle scanning arrays (WASAs) require radiating elements capable of broad beamwidths and circular polarization.
• Existing solutions often face limitations in bandwidth, beamwidth, or polarization purity.

Purpose of the Study:

• To design and validate a wide-band, wide-beam circularly-polarized slot-coupled (WWCS) radiating element.
• To achieve high polarization purity and impedance matching for WASA applications.

Main Methods:

• Utilized a customized System-by-Design (SbD) method for radiator synthesis.
• Employed numerical assessment and tolerance analysis for design validation.
• Conducted experimental verification on a PCB-manufactured prototype.

Main Results:

• A representative WWCS radiator achieved a fractional bandwidth (FBW) of approximately 15% at 2.45 GHz.
• Demonstrated a half-power beam-width (HPBW) of ~180 degrees in all elevation planes.
• Exhibited high polarization purity with an axial ratio (AR) of 3.2 dB and cross-polar discrimination (XPD) of 15 dB at broadside.

Conclusions:

• The synthesized WWCS radiating element is a competitive solution for large WASAs.
• The design offers a compelling combination of wide bandwidth, wide beamwidth, and circular polarization.
• Experimental results confirm the practical viability of the WWCS radiator for advanced antenna systems.