Extremely Low-Profile Monopolar Microstrip Antenna with Wide Bandwidth

Area of Science:

• Electrical Engineering
• Antenna Theory
• Wireless Communication

Background:

• Swarm sensor networks require compact, efficient antennas for high-speed mobile operation.
• Existing antennas often struggle to balance low profile, omni-directional patterns, and wide bandwidth.

Purpose of the Study:

• To propose and validate a novel, low-profile monopolar microstrip antenna.
• To achieve omni-directional radiation and wide bandwidth for high-speed mobile applications.

Main Methods:

• Utilized a symmetrical center feeding network and six arrayed patches for a hexagonal radiator.
• Incorporated partially loaded ground-slots to enhance radiation and tune impedance bandwidth.
• Analyzed degenerated non-fundamental TM02 modes (even and odd) for broad bandwidth operation.

Main Results:

• Fabricated antenna features an ultra-thin substrate (0.254 mm).
• Achieved 1.5-wavelength resonant monopolar radiation.
• Demonstrated a wide impedance bandwidth of 855 MHz (15.24% fractional bandwidth) at 5.57 GHz.

Conclusions:

• The proposed antenna design successfully meets the requirements for high-speed moving swarm sensor networks.
• The design offers a practical solution for low-profile, wideband, omni-directional antenna applications.
• The use of degenerated TM02 modes is effective for achieving broad bandwidth in microstrip antennas.