Power Bank Coupler

The power bank coupler by Fraunhofer IIS makes the parallel amplification of signals and multi-carrier linearization along with loss-free coupling possible. The signal coupling process is used when multiple signals are to be transmitted over one antenna. This is advantageous in various applications such as on ships where there is only one transmitting antenna for sending multiple, frequency-agile shortwave signals. Applications in the area of public safety benefit in particular from this efficient, reliable coupling process.

Without the power bank, each signal is amplified individually, so they have to be recombined after final amplification. With broadband coupling, this process results in high losses which can be avoided with a power bank. A power bank consists of power amplifiers that simultaneously intensify several signals at different frequencies and then transmit them using a single antenna. This requires high linearity to prevent from intermodulation of individual signals.

A special feature of the power bank coupler developed by Fraunhofer IIS is multi-stage linearization with digital predistortion, an innovative digital and analog feedforward loop. Together, these suppress the auxiliary lines to more than 90 dBc with no limitation on the selection of frequency for individual transmission signals.