Rf Connection; Ground Connection - Sierra Wireless MC5725 Hardware Integration Manual

Note: To disconnect the
antenna, make sure you use the
Hirose U.FL connector removal
tool (P/N UFL-LP-N-2(01)) to
prevent damage to the module
or coaxial cable assembly.
Rev 1.9.1 Feb.09
In the event of a discrepancy in values between this guide and the Product Specification Document (PSD), the PSD takes precedence.

RF connection

When attaching an antenna to the module:
Use a Hirose U.FL connector (model
•
U.FL #CL331‐0471‐0‐10) to attach an antenna to a
connection point on the module, as shown in Figure 3‐1 (the
main RF connector on the top side; the diversity RF or GPS
connector on the bottom side).
Match coaxial connections between the module and the
•
antenna to 50 Ω.
Minimize RF cable losses to the antenna; the recommended
•
maximum cable loss for antenna cabling is 0.5 dB.
Figure 3-1: Antenna connection points and mounting holes

Ground connection

When connecting the module to system ground:
Prevent noise leakage by establishing a very good ground
•
connection to the module through the host connector.
• Connect to system ground using the two mounting holes at
the top of the module (as shown in Figure 3‐1).
• Minimize ground noise leakage into the RF.
Depending on the host board design, noise could potentially
be coupled to the module from the host board. This is
Proprietary and Confidential
RF Integration
39