High-Frequency Performance Improvement of LPDA for EMC/EMI Measurements

A log-periodic dipole array with improved high-frequency performances for EMC/EMI measurements is proposed in this paper. In the proposed design, a saw-toothed shaped feed line is implemented. This modified feed arrangement allows dipole elements to be placed in the same horizontal plane, effectively suppressing the generation of the undesired vertical component electric field. The proposed LPDA offers on average VSWR of 1.49:1, a gain of 6.7 dBi, an FBR of 23.4 dB, an XPI of 26 dB, and E-plane HPBW of 63.6°.