Dual-Band Antenna with Pattern and Polarization Diversity

Area of Science:

• Antenna Engineering
• Electromagnetics
• Wireless Communications

Background:

• Traditional antennas often exhibit limited pattern diversity, restricting their performance in complex wireless environments.
• Achieving orthogonal radiation patterns across multiple frequency bands is crucial for advanced communication systems.

Purpose of the Study:

• To design and validate a pattern-diversity antenna capable of generating distinct radiation patterns at two different frequency bands.
• To investigate the antenna's polarization diversity characteristics and port isolation performance.

Main Methods:

• A novel antenna structure comprising a central circular antenna and two annular ring antennas with individual ports was proposed.
• The antenna design incorporated shorting an array in the inner part of the annular ring antennas and positioning the outermost port orthogonally to enhance port isolation.
• The fabricated prototype was experimentally evaluated to measure its bandwidth and isolation characteristics.

Main Results:

• The proposed antenna demonstrated orthogonal broadside radiation patterns at lower bands (port 1 and 3) and orthogonal conical radiation patterns at higher bands (port 1 and 2).
• Excellent port isolation values of -26.7 dB and -30.1 dB were achieved at the two respective frequency bands.
• The antenna achieved -10 dB bandwidths of 240 MHz (5.71-5.95 GHz) and 210 MHz (7.69-7.9 GHz) at the target frequency bands.

Conclusions:

• The developed pattern-diversity antenna successfully provides distinct radiation patterns and polarization diversity across two frequency bands.
• The proposed design offers high port isolation, making it suitable for advanced wireless communication systems requiring multi-band operation.
• Experimental validation confirms the antenna's capability to meet the specified performance metrics for diverse applications.