BT900-Sx Hardware Integration Guide
Intelligent BTv4.0 Dual Mode Module
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area is ~5.18 mm wide, 31.7 mm long; with PCB dielectric height 0.6 mm sitting under the BT900-SA
antenna.
A different host PCB thickness dielectric will have small effect on antenna.
The antenna-keep-out defined in Host PCB Land Pattern and Antenna Keep-out for BT900-SA applies
when the BT900-SA is placed in the corner of the host PCB. When BT900-SA cannot be placed as
such, it must be placed on the edge of the host PCB and the antenna keep out must be observed. An
example is shown in
Figure 4: Antenna keep-out area (shown in red), corner of the BT900 development board for BT900-SA module.
6.3.2
Antenna keep-out and Proximity to Metal or Plastic
Checklist (for metal/plastic enclosure):
The minimum safe distance for metals without seriously compromising the antenna (tuning) is 40 mm
top/bottom and 30 mm left or right.
Metal in close proximity to the BT900-SA chip monopole antenna (bottom, top, left, right, any
direction) will have degradation on the antenna performance. The amount of degradation is system-
dependent; some testing will be required in your host application.
The presence of metal closer than 20 mm starts to significantly degrade performance (S11, gain,
radiation efficiency).
We recommend that you test the range with a product mock-up (or actual prototype) to assess the
effects of enclosure height and the applicable material (metal or plastic).
6.4
External Antenna Integration with BT900-SC
Please refer to the regulatory sections for
, and
for details of use of BT900-Sx with external
antennas in each regulatory region.
The BT900 family has been designed to operate with the external antennas listed below (with a maximum
gain of 2.0 dBi). The required antenna impedance is 50 ohms. See
External antennas improve radiation efficiency.
Table 16: External antennas for the BT900
External Antenna PN
Mfg.
Type
Gain (dBi)
Connector Type
BT900 PN
An
te
nn
a K
ee
pou
t
BT900-SA module
Note: 1. BT900 module placed on edge of host PCB.
2. Copper cut-away on all layers in the Antenna Keep-out
area under the BT900 on the host PCB.