Hardware Development Guide of Module Product
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3G module cannot go on the right angle, cannot be crushed or worn. The RF cable
should better be wired close to the ground of main board.
7.3.2.6
Matching Circuit of Antenna
If the module RF interface needs to be transferred with the antenna interface, when
designing the main board circuit, the micro stripline or stripline between the module
RF testing console and the antenna interface RF testing console should be
designed by the 50ohm impedance, and the dual-L model matching circuit is
reserved. If the antenna RF connector is directly inserted to the module RF testing
console, the transfer between the module RF port and the antenna interface can be
saved.
7.3.2.7
Type of Antenna RF Cable & RF Connector
The antenna RF connection cable usually adopts GBE(TW) and Shenyu (Mainland),
or Japanese Somitomo and Shin Din. The antenna RF cable usually adopts a line
width of 1.37mm. The antenna RF connector usually adopts Japanese IPX, or HRS,
while the price of the latter is higher.
7.4
Suggestions for EMC & ESD Design
During the design of the whole set, the user needs to fully consider the EMC
problem caused by the signal integrity and power integrity. During the layout and
wiring of peripheral circuits, for the wiring of power and signal cables, keep a
distance of 2 t imes of the line width, so as to effectively reduce the coupling
between signals and keep a clean reflux path for the signal. During the design of
peripheral power circuits, the de-coupled capacitor should be placed closed to the
module power PIN, the high-frequency high-speed circuit and the sensitive circuit
should be placed far away from the border of PCB. They should better be separated
during layout, so as to reduce the interference between them and protect the
sensitive signal. For the circuit or device on the side of system board that might
interfere the module, it should be shielded during design.
ZM5202 is embedded on the side of system board, so the user needs to make the
ESD protection during design. For the key input/output signal interface, such as the
