R&S®FK2100/FK2100M Antenna Tuning Units (ATU)

The Antenna Tuning Unit R&S^®FK2100 belongs to the R&S^®XK2000 equipment family. It automatically matches antennas, in particularvery short antennas, to the 150 W HF Transceiver R&S^®XK2100. The sturdy and water- proof plastic casing of R&S^®FK2100 is shock- and UV-resistant and thus ideally suited for mobile applications. The R&S^®FK2100M, which is a seawater- and drop-resistant version of the R&S^®FK2100, is especially designed for shipboard applications and can match antennas with very low ohmic resistance.

Particular attention was paid to obtaining effective lightning protection. Both ATUs are fully arc-protected against direct lightning strokes. They are tested to withstand arcs of 10 kV/10 kA. An automaticBIT (built-in-test) is provided for fault detectionand reporting to the R&S^®XK2100 transceiver.

For the R&S® FK2100, a maximum of 100 customer-defined channels can be stored in a non-volatile memory. The stored channels can be even called up in silent mode, i.e. without emission of RF power.

The R&S® FK2100M offers silent tuning capability over the full frequency range of 1.5 MHz to 30 MHz.

Before the ATU can be used for an application, it must be connected to an antenna to “learn” its characteristic. Learning takes place in a user-defined frequency range in the HF band (1.5 MHz to 30 MHz).

The ATU “learns” the antenna characteristic by receiving tuning data for a maximum of 1500 predefined frequencies. Once the tuning data for these frequencies is known and stored, the typical ATU setting time is less than 30 ms. The advantage for the user is the low probability of intercept (LPI), since ATU frequency setting takes place very quickly and without any emission of RF power.

With a single cable between transceiver and ATU carrying RF, supply voltage and all bidirectional control data, the R&S® FK2100M is very installationfriendly.