A Miniaturized Log-Periodic Dipole Antenna Using Dual-Band Top-Loaded Dipoles as Radiating Elements

In this paper, we focus on the design of miniaturized microstrip log-periodic dipole array (LPDA) antenna. An LPDA miniaturized in both two dimensions is developed at 1–10 GHz. A classic microstrip LPDA antenna is firstly designed as the benchmark. We replace the classic dipole with a dual-band dipole to make the resonant points distribution more uniform, which reduces the axial dimension of the antenna. Then, the T-shaped top loading is used to extend the current path and reduce the lateral dimension of the antenna. Compared with the classic LPDA, the miniaturized LPDA features 15% and 21% profile shrinkage in lateral and axial orientations.