Circularly Polarized Dual-Band Terahertz Antenna Embedded on Badge for Military and Security Applications

Abstract

Terahertz antennas have got much attention in the field of security and military applications. As terahertz antennas are the perfect tools for short-distance communication for the armed forces. Therefore, in this research, a compact size dual-band circularly polarized (CP) microstrip patch terahertz antenna embedded on the badge is designed and simulated for military and security applications. As the badge is being stitched with the uniform or cap of the officers that is why the material used for the badge is Jeans with relative permittivity ε_r = 1.78 and the loss tangent tanδ = 0.085. The proposed antenna consists of three layers, i.e., a flexible substrate, a single element slotted patch, and a full ground plane. The antenna is being operated in the range of 0.126–0.133 THz and 0.184–0.194 THz for security and military applications. As the antenna is dual band so it will receive the data at one frequency and transmit the data to another frequency and the pattern radiation of the antenna is broadside at both frequencies. The overall size of the design is 1.5 × 1 × 0.15 mm³, and the patch is printed on a polyimide substrate with relative permittivity ε_r = 3.5 and the loss tangent tanδ = 0.0027. The simulated results like realized gain, radiation efficiency, and 10 dB impedance bandwidth at terahertz frequencies are found to be 4.87 dB and 5.59 dB, 89.6% and 77.9%, and 0.651 THz and 0.979 THz, respectively. The antenna gives circularly polarized behavior at both frequencies and has an axial ratio of less than 3 dB. The antenna is designed in computer simulation technology (CST) software and the simulated results proved that this proposed terahertz antenna is well-suited for security and military applications. As the antenna is made up of flexible substrate that is why bending analysis of the antenna along the x-axis and y-axis is also discussed in this article. Furthermore, in the future we will try to increase the gain, make the size more compact and to increase the bandwidth.