Schwarzbeck HLC 27 Dipole Antenna

The HLC 27 is a Compact Dipole Antenna for automotive immunity testing, embedded in a plastic housing. The original proposal of ISO 11452-9 had significant drawbacks, which made a practical realisation impossible. Especially the small effective antenna area, high losses and high sheath currents were the main disadvantages of the original design. A shortened dipol with balun, fitting into the original housing was choosen to eliminate the previous mentioned drawbacks.

In order to maintain a high degree of symmetry, the coaxial antenna connector leaves the antenna at the center of the rear mounting bolt. This prevents the generation of unwanted sheath currents very effectively. A further reduction of sheath currents can be achieved using the optional coaxial cable loaded with clamp-on ferrites.

The antenna housing comes with two fixture bolts, which can be used to mount the antenna either in vertical or horizontal orientation.

CAUTION

The BNC antenna connector must not be touched during TX-operation due to hazardous voltages and fieldstrength! The relevant safety standards for exposition to electromagnetic fields must be considered. Immunity tests shall only be made by skilled personnel, being familiar with possible hazards. Testing must take place in appropriate environments (anechoic chamber or shielded room).

Due to its construction the antenna can be de-tuned when approaching too close to other devices. This may degrade the impedance matching and generate unwanted sheath currents, which can lead to high temperatures of the snap-on-ferrites of the coaxial cable. In such cases the transmit power should be switched off until the ferrites have cooled down.

The HLC 27 is part of a series of antennas described in ISO 11452-9.

Standing Wave Ratio