Browse Categories
Your quote request
View Quote Request

Log Periodic Antenna FAQ's

As part of our commitment to provide you with information that adds value to your work, A.H. Systems is continuously producing articles and application notes on specific uses of our products. Our complete library of technical articles and application notes is available below for public use as an open reference for the RF engineering community. If you need information on a topic you don’t see here or you require additional technical support, we can help. Contact support to talk with one of our engineers for answers.

Common Questions

A Log Periodic Antenna is a multi-element directional antenna with elements gradually decreasing in length. Also known as a dipole array, the Log Periodic Antenna is designed to operate over a wide frequency range.

Log-periodic antennas are designed to work across a wide range of frequencies; Yagi antennas are optimized for one frequency. The Yagi antenna will give higher gain at its optimal frequency; log-periodic antennas will have lower gain across a wide range of frequencies.

The calibration measurement point for a 1 meter separation is from the tip (nearest point) of the antenna. The measurement point for the 3 and 10 meter separation is at the midpoint of all the elements. There will be a sticker indicating the emission measurement reference point.

Antennas act differently in the near field… Many calibration standards require different testing separation distances. Once the antenna is in the far-field, the antenna response does not change with increasing distances.

Yes, contact the factory with your requirements.

While the antennas can be used outdoors, their main design is for a laboratory environment. The antenna is made up of aluminum, stainless steel, brass with an RF fed cable. We have had customers place the antennas in an outdoor environment for many months and have not had any issues.

Mount the antenna such that the elements are parallel to the ground for horizontal polarity, or perpendicular to the ground for vertical polarity.

With the example above, a half power beamwidth of 80 degrees at the lower end, the maximum coverage would be about 1.7 Meters, but at the high end of the frequency range with a half power beamwidth of 20 degrees, the coverage would only be 35cm. Here is a great tool (https://www.ahsystems.com/EMC-formulas-equations/Antenna-beamwidth-coverage-calculation.php) to help calculate the maximum coverage that the antenna will cover from a specified distance.

50 ohm and rated high enough in frequency to cover the operating band of the log periodic antenna. We offer a wide range of cables that can be custom made to your specifications.

WIND LOAD = 1/2 x AIR DENSITY x (WIND VELOCITY)2 x (CROSS SECTIONAL AREA)
newsletter