GPS receiver A1080-A
8 Use of Antenna
8.1 Connection of RF Signal
The ANT pin is used to connect the receiver with the GPS antenna. The design of
the antenna connection has to be done strictly according to RF design rules. A 50
Ω
PCB strip line is required. The following drawings shall explain the guidelines. A
major rule is to keep the strip line as short as possible. Additionally, antenna ground
(GNDANT) should be routed to the ground plane of the PCB (the ground plane is
on a lower PCB layer) by via as demonstrated in the drawing.
Figure 9: Antenna connector strip line A1080-A
In order to gain the impedance of 50
Ω
, the width of the strip line needs to be calcu-
lated. It depends on the thickness or height of the PCB layer (both parameters are
shown in following drawing). For the calculation, it is assumed that the PCB mate-
rial is FR4.
Figure 10: Strip line parameters A1080-A
In this case, the width should be about 1.8 times the height of the PCB:
W = 1.8 x H
In the example, one would get a width of W = 1.8 x 0.8mm = 1.44mm.
V2.3 - 07/07
User’s Manual
Page 19 of 31
