BGS3 Hardware Interface Description
4.2 RF Line Routing Design
67
BGS3_HD_v01.000d
Page 66 of 109
2010-03-26
Confidential / Released
Depending on specific material characteristics, on standard FR-4 glass fabric epoxy composite
substrates (as here with 1.2mm thickness) a line width of 800µm, within a neighbouring ground-
plane with a clearance zone of 200µm to both sides, results in an RF line impedance of
50Ohms, as shown in
These line parameters - 800µm width, 1.200µm distance to ground and 200µm distance to both
sides - are used for the wiring outside the area populated by the BGS3 module, i.e., the trans-
mission line to the antenna connector as shown in
Within the area populated by the EGS3 module, the RF line width shall be reduced to 700µm
and the distance to the surrounding ground area shall be increased to 450µm. This modification
compensates for the module's permittivity that increases the line capacitance.
The RF line on the application board populated by the module should lead directly from the an-
tenna pads to the side of the module thereby using the slightly carved out area that is shown
in
.
For matching purposes, two components can be populated on the interface board. On the sam-
ple interface board the serial component is populated with a 0-Ohm-resistor (size 0402), the
shunt element is set to N.C. (not populated).
