Справочник Пользователя для ZTE Corporation MG3732
MG3732 module
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protector during the design to avoid damaging the module.
D1 is USB2.0 ESD protector in the figure, and the Junction capacitance is small than 3P. VBUS is connected to
the external host VBUS. The USB operating voltage is: 4.75—5.25V with the typical value of 5V. See figure
4-5.
D1 is USB2.0 ESD protector in the figure, and the Junction capacitance is small than 3P. VBUS is connected to
the external host VBUS. The USB operating voltage is: 4.75—5.25V with the typical value of 5V. See figure
4-5.
Figure 4-5 USB Interface Circuit Reference Design Diagram
4.8 Antenna Interface
Proper measures should be taken to reduce the access loss of effective bands, and good shielding should be
established between the external antenna and the RF connector. Besides, the external RF cables should be kept
far away from all interference sources such as high-speed digital signal or switch power supply.
According to mobile station standard, stationary wave ratio of antenna should be between1.1 to 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.
established between the external antenna and the RF connector. Besides, the external RF cables should be kept
far away from all interference sources such as high-speed digital signal or switch power supply.
According to mobile station standard, stationary wave ratio of antenna should be between1.1 to 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.