User's Manual
Table Of Contents
- Contents
- Table Index
- Figure Index
- 0. Revision history
- 1. Introduction
- 2. Product concept
- 3. Application interface
- 3.1. Pin
- 3.2. Operating modes
- 3.3. Power supply
- 3.4. Power on and down scenarios
- 3.5. Charging interface
- 3.6. Power saving
- 3.7. Summary of state transitions
- 3.8. RTC backup
- 3.9. Serial interfaces
- 3.10. Audio interfaces
- 3.11. SIM card interface
- 3.12. SD card interface
- 3.13. PCM interface
- 3.14. ADC
- 3.15. Behaviors of the RI
- 3.16. Network status indication
- 3.17. Operating status indication
- 4. Antenna interface
- 5. Electrical, reliability and radio characteristics
- 6. Mechanical dimensions
- 7. Storage and manufacturing
- Appendix A: GPRS coding schemes
- Appendix B: GPRS multi-slot classes
M80 Hardware Design
M80_HD_V1.2 - 72 -
4. Antenna interface
The Pin 63 is the RF antenna pad. The RF interface has an impedance of 50Ω.
Table 29: Pin definition of the RF_ANT
4.1. RF reference design
The reference design for RF is shown as below.
RF_ANT
0R
MODULE
NMNM
Figure 47: Reference design for RF
M80 provides an RF antenna PAD for customer’s antenna connection. The RF trace in host PCB
connected to the module RF antenna pad should be micro-strip line or other types of RF trace,
whose characteristic impendence should be close to 50Ω. M80 comes with grounding pads which
are next to the antenna pad in order to give a better grounding. Besides, a ∏ type match circuit is
suggested to be used to adjust the RF performance.
To minimize the loss on the RF trace and RF cable, take design into account carefully. It is
recommended that the insertion loss should meet the following requirements:
GSM850/EGSM900 is <1dB.
Name
Pin
Description
GND
62
Ground
GND
61
Ground
RF_ANT
63
RF antenna pad
GND
66
Ground
GND
65
Ground
GND
64
Ground