GPS antenna tuning

https://synzen.com.tw/products/lodestar antenna is used for the Rhino Tracker. This is the tuning process for air.

Schematic

Equipment

For GPS antenna tuning a MegiQ VNA-0460 VNA was used. VNA and cable were calibrated with custom calibration kit.

Measurements with recommended component values

Datasheet recommended component values

Because one of the component was not in stock at office w tried with 10pF instead of 8.2pF on C2

• C13 - 15pF

• C3 - 1pF

• C2 - 10pF

Change recommended components 1

• C13 - 15pF

• C3 - 1.5pF

• C2 - 11pF

Change recommended components 2

• C13 - 15pF

• C3 - 1.5pF

• C2 - 6.8pF

Conclusion

At this point we saw that we are not getting anywhere.

Measurements with new pi network configuration

Measurements 1

• C13 - 15pF

• C2 - 1pF

• C3 - 1pF

Measurements 2

• C13 - 15pF

• C2 - 1pF

• C3 - 1pF

Measurements 3

• C13 - 15pF

• C2 - 1pF

• C3 - 2.2pF

Measurements 4

• C13 - 10pF

• C2 - 1pF

• C3 - 2.2pF

Measurements 5

• C13 - 22pF

• C2 - 1pF

• C3 - 2.2pF

Measurements 6

• C13 - 10pF

• C2 - 1pF

• C3 - 3.3pF

Measurements 7

• C13 - 10pF

• C2 - 3.3pF

• C3 - 3.3pF

Measurements 8

• C13 - 10pF

• C2 - 4.7pF

• C3 - 3.3pF

Measurements 9

• C13 - 10pF

• C2 - 4.7pF

• C3 - 4.7pF