Panasonic 松下GSM移动终端EMI对策

Panasonic GSM移动终端EMI对策减噪对策(EMI)和抗静电对策(ESD)

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通信制式
FDMA(Frequency Division Multiple Access)

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Po

t

freq.
TDMA(Time Division Multiple Access) CDMA(Code Division Multiple Access)

Po

t

Po

t

freq.

freq.

Burst Noise 的产生原理 1

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TDMA 载波: 900,1800,1900MHz

Carrier wave

RF Circuit BB Circuit Audio codec

Receiver

Burst Noise

Microphone

Base station

900MHz

217Hz

Handset

Burst Frequency Burst Acoustic Noise

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Normal Mode

Common Mode

GND

Solution
Inductor/Chip Bead core

Solution
Common mode coil

Capacitor

Burst Noise 的产生原理 2

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<1> 载波(900MHz/1800MHz)侵入音频线 = Common mode Noise

Normal mode Noise Base Band IC Audio Control Circuit Envelope detection (Diode detection) = Burst Noise = Acoustic Noise