Design of Log Periodic Dipole Array (Lpda) with Cross-shape Eaching for Uhf-vhf Application (200-1500mhz) With Band Notch of (800mhz -1000mhz)
Computer analysis reveals that the anomalous behavior of symmetric Log Periodic Dipole Array (LPDA)Antennahas infloenced by different parameters . The most important is mainly due to the radiation of the dipole elements in the anomalous radiating region which is excited by the transmission line resonance of the feed structure. In the design by changing the element spacing , changes of length of each element in the LPDA antenna and define cross eaching in an boom of an antenna in middle of the specified element the result is the return loss less from 200 MHZ to 1500 MHZ other than the notch between 850 MHZ 950 MHZ according to the simulation results.The log-periodical Dipole Antenna (LPDA) is a kind of ultra wide-band antennas. To achieve the purpose of miniaturization of the LPDA in radiate direction, this paper presents anunusual structure log-periodically loaded with slot cross-shape design.