Users Manual

Interior
1. Introduction
The DDA is an automotive roof top antenna module with integrated Bluetooth transceiver for special
usage. The Bluetooth circuit and electronics is designed to tunnel a not public described data stream
via Bluetooth generic protocol. The device rejects any communication requests from Bluetooth devices
not supporting the nonpublic payload format. The device is fully integrated to the electronics of the
car. The device will be integrated in the car only by the car-manufacturer or in case of replacement by
a professional garage. The end-user does not have to do any installations or adjustments. There will
be no aftermarket modules available since the device needs to have a full range of ECUs available to
communicate with.
The DDA is connected with the CAN-Bus of the car to communicate with the rest of the ECUs.
Additionally it has an antenna with integrated LNA circuits for reception of GNSS (GPS, GALILEO,
GLONASS, BEIDOU) and SDARS as well as an antenna for cell phone communication (2G, 3G and 4G)
with frequency diplexer for 868 MHz ISM-Band. The availability of the separate ISM path is given for
versions without SDARS only. The Bluetooth transmitter is the only system with digital IO. The other
functions are analog circuits like in well known roof top car antennas.