Design and Realization of Miniaturized HF Soft Log-Periodic Dipole Antenna

The conventional high frequency Log-periodic Dipole Antenna (LPDA) is very large in the lateral size, causing the construction difficulty. A miniaturized soft High Frequency (HF) LPDA work in 4 MHz to 30 MHz is presented. The elements of the antenna adopt three-dimensional triangular dipole and plane quadrilateral dipole, and the stay wires are loaded as the longest element, so that the work frequency of antenna is effectively extended. The longest antenna element adopts folded dipole antenna, which eliminates the influence flank truss on antenna performance. Full-wave simulation and test results showed a stable directional pattern and lower Voltage Standing Wave Ratio (VSWR) over the impedance.