R&S®FK2900M Antenna Tuning Unit
For matching of HF transceivers to antennas used in stationary and shipboard applications
Silent tuning over the entire frequency range from 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.
Repeated tuning
A change in environmental conditions may slightly alter the actual antenna tuning data as compared to the stored data.
The quality of antenna matching is therefore checked during operation by means of an integrated VSWR measuring device. If the required VSWR (<1.5:1) is not attained, the ATU can be retuned in less than 200 ms.
