User Manual
This document is not allowed to
transmit without ZTE Corporation
’s
permission
©ZTE CORPORATION All rights reserved
9
and RF connector. Besides, external RF cables should be kept far away from all interference sources
such as high-speed digital signal or switch power supply.
According to the standard for mobile devices, the stationary wave ratio of MG2639_V3 module’s
antenna should be between 1.1 and 1.5, and input impedance is 50 ohm. Different environments may
have different requirements on the antenna’s gain. Generally, the larger gain in the band and smaller
outside the band, the better performance the antenna has.
Isolation degree among ports must more than 30dB when multi-ports antenna is used. For
example, between two different polarized ports on dual-polarized antenna, two different frequency
ports on dual-frequency antenna, or among four ports on dual-polarized dual-frequency antenna,
isolation degree should be more than 30dB.
MG2639_V3 module provides both GSM and GPS antenna interface, and either interface provides
both RF socket and stamp-hole connection method; therefore users can select reasonably according
to the product form to optimize the cost of BOM.
Scenario 1
：
PIN2 and PIN16 are respectively used as the input pin for GSM and GPS antenna. Pay attention to
the following when using it as the antenna’s feed PIN:
（
1
）
The feed connected to PIN2 or PIN 16 is 50ohm micro-strip or strip line. To approach the
module, put π shape matching network for later tuning. See π shape matching network
in the diagram below:
Figure 2-1 π shape matching network diagram
（
2
）
The RF wires must be kept away from the GND, and generally the distance should be 3 times
of the width of RF wires.
