The Anritsu PIM Master is capable of producing up to 100 Watts of RF power in the cellular communications bands. Users must take precautions to minimize exposure to these RF fields:
Always terminate the output port of the test equipment into a load, a loaded line, or a line that will radiate or absorb the energy before beginning a PIM test.
Confirm that the PIM Master RF power is off after a PIM test.
Always confirm that the RF power is off before disconnecting a coaxial connection, otherwise RF burns may result. Immediate burns to fingers or eyes can result from exposure to live connectors.
Ensure all antenna’s under test are placed so that no personnel are exposed to RF levels that exceed the maximum allowable exposure.
Introduction
The PIM Master is an integrated source and receiver that generates a high‑power signal that excites micro arching and PIM. These signals are picked up by the on‑board receiver.
Anritsu has developed the PIM Master to verify and troubleshoot Passive Inter‑Modulation (PIM). The PIM Master generates two high‑power tones, usually in the transmit band of interest. The Anritsu family of handheld RF instruments has a PIM Analyzer mode for controlling the PIM Master. These handheld instruments display and measure the third‑order, fifth‑order, or seventh‑order lower intermodulation product reflecting back from the DUT to the PIM Master. In addition, the PIM Master can measure the Distance‑to‑PIM of multiple PIM sources, providing the distance to the source and its relative magnitude, both inside the antenna system and beyond.
The current standard of PIM testing utilizes this system of two primary carriers and a calculated PIM frequency. This system is monitored via a spectrum analyzer. This provides a measurement of the overall linearity of the antenna system and the surrounding environment.
As more power goes up the antenna lines, a coaxial connection is more likely to cause a fault on a tower. Traffic through the site plays a big part. A relatively quiet site will not usually exhibit the same performance problems as a busy site.
PIM testing is a measure of construction quality. Poor construction quality results in self‑interference. Line Sweep testing and PIM testing are distinctly different tests. Both are important and are accurate measures of the ability of a cell site to provide service and to perform optimally. Line sweeping measures the signal losses and reflections of the transmission system.
PIM testing measurements reflect the overall linearity of an antenna feed line, and Line Sweep measurements reflect the overall impedance matching of all of the components in an antenna feed line. Both tests need to be performed to ensure the overall quality of an antenna feed line.
The main reason to use a PIM test is that it is the most comprehensive measure of electrical connection quality that is commercially available.