AN3141

Filter placement

Doc ID 17004 Rev 1

11/14

4

Filter placement

The goal of filters is to avoid flex radiation at mobile phone reception frequencies.

Consequently, filters need to be placed just before the flex connector, at the digital signal

generator side.

For implementation on the LCD link, filters should be placed on the main PCB, between

baseband processor and the flex connector. By contrast, for the camera link, filters will be

placed on the camera PCB, as the signal comes from the camera to go to the baseband

processor. In case of a bidirectional link, both sides of the flex need to be filtered.

Figure 13 show filter placement for LCD and camera links.

Figure 13.

Filters placement on LCD and camera links

Camera

Antenna

LCD

BB

Flex

Antenna

LCD

BB

Flex

Filters placement