Laird BT740-SA, Руководство по интеграции оборудования

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Enhanced Class 1 Bluetooth v2.1 Module
Hardware Integration Guide
Americas: +1-800-492-2320 Option 2
Europe: +44-1628-858-940
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www.lairdtech.com/bluetooth
16 CONN-HIG-BT740

Ensure there is no exposed copper on the underside of the module (refer to land pattern drawing of
BT740-Sx).
6.3 PCB Layout on Host PCB for BT740-SA
6.3.1 Antenna keep-out on host PCB
The BT740-SA has an integrated chip antenna and its performance is sensitive to the host PCB. It is critical to
locate the BT740-SA on the edge of the host PCB (or corner) to allow the antenna to radiate properly. Refer
to guidelines in the section
PCB Land Pattern and Antenna Keep-out area for BT740-SA
. Some of the
guidelines are repeated below.

Ensure there is no copper in the antenna keep-out area on any layers of the host PCB. Keep all
mounting hardware and metal clear of the area to allow proper antenna radiation.

For best antenna performance, place the BT740-SA module on the edge of the host PCB, preferably in
the corner with the antenna facing the corner. An example shown in
Figure 6-1 .

A different host PCB thickness dielectric will have small effect on antenna (the BT740 carrier
development board (used for antenna performance evaluation) thickness was 0.78 mm).

The antenna-keep-out defined in
PCB Land Pattern and Antenna Keep-out area for BT740-SA
applies
when the BT740-SA is placed in the corner of the host PCB. When BT740-SA cannot be placed as such,
you must place it on the edge of the host PCB and use a modified antenna keep out. This antenna
keep-out modification is shown in
Figure 6-2 (antenna keep-out is extended by 8 mm on both sides).
Figure 6-1: BT740-SA placement in the corner of host PCB.
Figure 6-2: BT740-SA placement in the edge (not corner) of host PCB (with modified antenna keep-out).