A Resonance Point Optimization Method for Axial Size Reduction of the Log-Periodic Dipole Array

A new resonance point optimization (RPO) is applied to reduce the log-periodic dipole array (LPDA) antenna's axial size. The resonance points are redistributed under the premise of the unchanged impedance bandwidth. And the required radiating elements number is reduced. In comparison with the classic LPDA, axial size reduction rates of 18% and 28% are achieved by two proposed RPO LPDAs with a working frequency band of 1-10 GHz. They consist of 19 and 15 elements respectively. An obvious size reduction rate of 44% in the axial direction is obtained through the RPO method at 2–20 GHz. The RPO design technique provides a reference to miniaturize the LPDA axially.