Chip Scale antenna initial position

GPS/GNSS Development Boards
1

I bought and mounted the [Chip scale GPS Antenna.

1.575Ghz VSWR is 1.3 with with return loss at 18.6dB.

Center frequncy as mounted is 1.58Ghz with VSWR at 1.2 and return loss is 20.16dB

Problem: several GPS devices fail to acquire initial data: no position

Solution: Connect alternate antenna for initial fix, remove and connect chip antenna for all subsequante fixes

Questions:

  1. What might cause the inital failure

  2. How might this be corrected](Antenna GPS Chip-Scale - GPS-09131 - SparkFun Electronics)

2

You are not getting enough signal with the chip antenna.

3

leon_heller:
You are not getting enough signal with the chip antenna.

This doesn’t make sense as the antenna works fine for subsequent updates.

It just does not work for cold start.

4

According to the description provided by SparkFun:

the gain is not as great (to be expected), but heck, if you can get a lock with this little guy, who cares?

That is a pretty big "if".
5

devpts:
This doesn’t make sense as the antenna works fine for subsequent updates.

This confirms that the signal is weak as a GPS usually requires a stronger signal to acquire the position and can track a weaker signal. If you look in the specs of the GPS you will notice something like

Tracking Sensitivity -160 dBm

Acquisition Sensitivity -148 dBm

Hope this help,

gm