Ultra-wideband Planar Log-periodic Slot Antenna with Exponential Shapes on Slot Edges

摘要

An improved method of using exponential curve shape on edges of log-periodic slots to decrease resonances and further reduce the antenna size is proposed. The proposed method is adopted to design a planar log-periodic slot antenna for ultra-wideband (UWB) applications. Numerical investigation shows that resonant frequencies can be decreased around 12.3% in low frequencies compared with the conventional planar log-periodic slot antenna with regular shape on edges of slots. Measured and simulated reflection coefficients and radiation patterns of the proposed antenna agree well with each other to demonstrate the validity. The measured vertical bar S11 vertical bar shows that the operating frequency range (vertical bar S11 vertical bar below -10 dB) is from 2.9 GHz to 11.36 GHz, covering the UWB spectrum (3.1 - 10.6 GHz). The proposed antenna has good radiation characteristics and antenna gains. The proposed antenna is a good candidate for the UWB applications.