Integration Guide

4117336 Rev 1.0 May 18, 2015 19
Hardware Integration Guide
Routing Constraints and
Recommendations
Figure 4. Antenna Microstrip Routing Example
5.2. Power and Ground Recommendations
Power and ground routing is critical to achieving optimal performance of the AirPrime AR7552 devices
when integrated into an application.
Recommendations:
 Do not use a separate GND for the Antennas
 Connections to GND from the AirPrime AR7552 should be flooded plane using thermal reliefs
to ensure reliable solder joints.
 VBATT is recommended to be routed as a wide trace(s) directly from the 4V supply to the
LGA pad.
5.3. Antenna Recommendations
The AirPrime AR755x devices are designed to provide diagnostics status of the antennas connected
to it.
 The Primary antenna interface is optimized for a multiband cellular antenna with a 10 kΩ DC
impedance between the antenna element and the ground reference.
 The GNSS antenna interface is optimized for a 5V active GNSS antenna supporting the GPS
L1 and GLONASS L1 FDMA bands. Refer to GNSS Antenna Diagnostics section.
Connecting the antenna ground reference to the vehicle chassis is not recommended since that has
been known to cause noise from the engine to couple into the audio of the device. It is ultimately up to
the integrator to evaluate this performance.