Compliance test tools: LISNs and antenna masts

Article By : Arturo Mediano

The mast is weather-proof, with all metal elements located in the base plate and the drive mechanism only maximum 0.4m above ground level.

« Previously: Troubleshooting tools: scanners and current probes

Thorsten Schloder, CEO/managing director of Germany-based INNCO Company, has explained some of the company's products, including the TW4000-PP-ET antenna mast (Figure 1). This mast is suitable for use in either open areas or in chambers.

__Figure 1:__ *The TW4000 antenna from INNCO.*

The mast's material is PVC and GFK. It's weather-proof, with all metal elements located in the base plate and the drive mechanism only (maximum 0.4 m above ground level). This mast offers antenna height from 1m to 4m with a total height of 4.6m.

INNCO offers adapters for all commercially available antennas with special designs available on request.

An interesting detail is that all antennas rotate around their axis during polarisation so as to eliminate any elevation errors. The video below shows the antenna in motion.

COM-Power conducted emissions tests equipment

Com-Power specialises in EMC test-and-measurement instruments, focusing on test equipment used to meet the regulatory requirements. In the Com-Power booth, I met with Travise Miranda to review the many options available from the California-based company.

Let me show you two interesting options: the LIN 120-A LISN (Line Impedance Stabilisation Network) and the ISN-T8 impedance stabilisation network, both in Figure 2.

[EMC2016 Com-Power]
__Figure 2:__ *LIN 120-A and ISN-T8 from Com-Power.*

LISNs are mandatory instruments if you are involved in conducted emissions to mains network. LIN 120-A is compliant with both CISPR 16-1-2 and ANSI C63.4. You can use it to provide your EUT a defined stable impedance. At the same time, you'll have good isolation from power source influences, thereby providing accurate and repeatable results.
Note that the LIN-120A includes one pair of single-conductor networks, housed together. They're installed in series with each current-carrying conductor in a single-phase, dual-phase or DC power system. You can switch in the front panel to the conductor you are interested to analyse (e.g. line or neutral). Obviously, you can add a second LIN-120A to accommodate 3-phase power systems.

COM-POWER offers two LISNs with separate outputs for each conductor (as the LI-125A). This is quite useful for troubleshooting conducted emissions when you're looking to identify both differential and common mode emissions. I like this option using a differential-mode rejection network.

The ISN-T8 is a typical ISN (impedance stabilisation network) used for RF telecom conducted emission testing as per EN 55022 in Europe.

Next: IEEE EMC 2016: Shielding materials »

Leave a comment