A Miniaturized Transmitting LPDA Design for 2 MHz-30 MHz Uses

A miniaturized horizontal polarized high frequency transmitting LPDA is presented. In use of the dipole transformation and antenna coefficient optimization methods, a 65% reduction in the size was achieved with the electrical performance kept in a competitive level. Full-wave simulation results showed a stable directional pattern and lower VSWR over the impedance bandwidth of 2 to 30 MHz. The gain bandwidth can reach the range of 4-30 MHz, meanwhile, there is only minor degradation on gain in frequencies under 4 MHz.