Integration Guide
Table Of Contents
- 1 Safety Precautions
- 2 Manual Overview
- 2.1 REFERENCES
- 2.1.1 ENFORA ENABLER III LPP PRODUCT DOCUMENTATION MANUALS
- 2.1.2 GSM DEVICE SPECIFICATIONS
- 2.1.3 FEDERAL COMMUNICATIONS COMMISSION (FCC)
- 2.1.4 FCC OFFICE OF ENGINEERING AND TECHNOLOGY (OET)
- 2.1.5 INDUSTRY CANADA
- 2.1.6 ENVIRONMENTAL REGULATIONS
- 2.1.7 MECHANICAL SPECIFICATIONS
- 2.1.8 RF AND EMI SPECIFICATIONS
- 2.1 REFERENCES
- 3 Introduction
- 4 Technical Specifications
- 5 Physical Interfaces
- 5.1 MODULE MOUNTING TO HOST BOARD (REFERENCE)
- 5.2 I/O PIN ASSIGNMENTS
- 5.3 CIRCUIT PROTECTION
- 5.4 CONTROL CONNECTOR SIGNAL DESCRIPTIONS AND FUNCTIONS
- 5.4.1 MODULE POWER (PINS 30, 31)
- 5.4.2 ON/OFF SIGNAL (PIN 4)
- 5.4.3 ON/OFF STATUS (PIN 5)
- 5.4.4 GENERAL PURPOSE INPUT SIGNALS (PINS 10, 11)
- 5.4.5 GENERAL PURPOSE OUTPUT SIGNALS (PINS 12, 13)
- 5.4.6 RESET SIGNAL (PIN 24)
- 5.4.7 USB (PINS 34, 35, 36)
- 5.4.8 SERIAL INTERFACES
- 5.4.9 HANDSET MICROPHONE INPUT (PINS 37, 38)
- 5.4.10 HANDSET SPEAKER OUTPUT (PINS 39, 40)
- 5.5 SUBSCRIBER IDENTITY MODULE (SIM) (PINS 42, 43, 44, 45, 46)
- 5.6 ANTENNA
- 6 GPS Performance
- 7 GSM/GPRS Modes of Operation
- 8 Software Interface
- 9 APPENDIX A - LIMITED WARRANTY
- 10 APPENDIX B - Regulatory Compliance
- 11 APPENDIX C - Glossary and Acronyms
- 12 APPENDIX E - Contacting Enfora
Enfora Enabler III LPP
Integration Guide Page 12 Revision: 0.00
Figure 3 - Example of a GOOD RF Thermal Relief
3.5.1.3 ANTENNA AND RF SIGNAL TRACE
The PCB trace that feeds the RF output port must be designed for a 50 ohm
characteristic impedance, coplanar, or routed into internal layers to keep the top
layer continuous around and underneath the Enabler module. Ample ground vias
should be provided around the RF contacts, the RF trace and launch pad. If
possible, keep I/O and power traces away from the RF port. This includes traces
running parallel or orthogonal to it. Thermal relief should not be used on the
antenna output port ground pads. The designer must pay close attention to the
size of the pad and thickness of the dielectric beneath the signal pad and trace.
Most PCB manufacturers can adjust the trace width to maintain 50 ohms
impedance if the traces are identified and instructions are included on the FAB
drawing. This service is typically provided at no or minimal additional cost.
For minimum RF emissions due to the fundamental frequency of operation, the
Enabler module works best with an antenna load that has a VSWR of 1.5:1 or
better. The antenna should not have gain at the harmonic frequencies, otherwise,
the conducted harmonics could get amplified to a point where the product no
longer passes type approval. However, for applications where antenna quality is
less than ideal, it is recommended to have a low pass filter (Pi structure with N=3) in
the RF path to the antenna. This is a secondary plan should there be a need to
lower harmonic levels at frequencies above the PCS band. The pad structure may
also be used to match the antenna load impedance, if required. If it is not needed,
a capacitor of low reactance may be used to bridge the Pi structure.
GOOD RF thermal