Design of a Super Wide Band Antenna and Measure of Ambient RF Density in Urban Area

A compact Super Wide band (SWB) antenna fed by coplanar waveguide (CPW) is proposed in this paper. The size of the antenna is <inline-formula> <tex-math notation="LaTeX">$140\times 100mm^{2}$ </tex-math></inline-formula> (<inline-formula> <tex-math notation="LaTeX">$0.16\lambda \times 0.12\lambda$ </tex-math></inline-formula>). The antenna originates from 3D volcano smoke antenna, and consists of a prolonged radiation patch and a symmetrical ground. Both the patch and ground were designed as smoothing structure, which can improve the impedance matching through a wide band. The simulated and measured bandwidth show that the antenna has a well-matched impedance bandwidth from 400MHz to higher than 20GHz under VSWR = 2 criterion, and the bandwidth ratio is greater than 50:1. The gain, efficiency and radiation pattern were all measured, and the maximum gain and efficiency are 6.3dBi and 96%, respectively. The antenna was also used to measure the ambient radiation frequency (RF) density in an urban area of Nanjing in China, which on the other hand proves the efficiency of this design.