A Compact Rectangular Ring Antenna with Meander Line for UHF Band Communications

This article describes the design of a low profile compact antenna operating on the ultra-high-frequency (UHF) range for wireless communication. The proposed design contains a probe through which rectangular ring excited, served as an antenna. The electrical size of this proposed design is 0.18λ
0
× 0.17λ
0
× 0.05λ
0
at resonating frequency of 405 MHz. The feeding probe has a length of 47 mm. Here, the antenna compactness is due to meander line inserted on the rectangular ring structure at this frequency. The proposed antenna design provides an omnidirectional radiation pattern with a bandwidth of 3.84 MHz. Radiation efficiency is more than 90%, and the average gain in the working band is 1.98 dBi at a resonating frequency of 405 MHz. Here, a low cost dielectric substrate of FR-4 is used for the antenna design. The advantages of the suggested design are low cost, low-profile, easy fabrication, high radiation efficiency and omnidirectional radiation pattern. The proposed design can be suitable for the underground mines communication.