Glossary  >  Log Periodic Directional Antenna (LPDA)

Log Periodic Directional Antenna (LPDA)


A Log Periodic Directional Antenna (LPDA) is an antenna with multiple elements, designed to operate over a wide spectrum and provide directivity, gain, and high bandwidth. There are several types of log periodic antennas, but the most commonly used is the log periodic dipole array (LPDA).

This antenna consists of a number of dipole elements in progressively increasing lengths from front to back. Each element is fed, but the phases are reversed between adjacent elements to ensure correct signal phasing between the elements.

Wilson High-Gain LPDA Antenna

Wilson High-Gain LPDA Antenna

Generally, LPDA antennas operate over a frequency range of about 2:1 and provide a gain of between 3 and 6 dB over a dipole. They are used in various applications where wide bandwidths are needed, including:

  • High Frequency (HF) communications: Accessing several frequencies over HF bands to allow communication despite variations in optimum working frequencies.
  • Ultra High Frequency (UHF) TV: Commonly used in television reception where channels are spread over a wide portion of the UHF band.
  • EMC measurements: Helping in the testing for radiated emission thanks to their ability to provide a flat response over a wide band of frequencies.
  • Other wide bandwidth applications: While LPDAs are not as commonly used as Yagi antennas due to their larger size and lower gain, they excel in applications that require wide bandwidth and directivity.

Example of Log Periodic Directional Antenna in a sentence:

"By design, log periodic directional antennas exhibit stable characteristics over a frequency range."

Synonyms: log periodic array, log periodic aerial

Related Terms for Log Periodic Directional Antenna: