Teseo LIV4F NO FIX

Starboy-1427 · ‎2025-03-29

Hi team,
i have built a custom gnss application for my UAV, using the teseo liv 4f module.
i have attached my circuit herewith, and also the corresponding output from the teseo suite.
The module has no fix always and is not locking onto any sat.
please look into my circuit and let me know the issue.
I have used a taoglass passive antenna(Acurra GNSS) for the circuit.

MHoll.2 · ‎2025-04-09

You are using a LNA (BGA535N6?), according to the data sheet, You have to connect the CTRL1 and CTRL2 input's.

Further more the data sheet suggests a serial inductor on the input side (for impedance maching).

Probably You could ask Taoglas for help on the impedance maching for the antenna.

The Bandpass filter used (B39162B4327P810?) seams to be only for the L1 Band, the LIV4F is a dual band receiver so You should use a dualband Bandpass filter. But this should give You anyway all the L1 band signals, so not the main problem at the monent.

Martin

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GalaxyQuest · ‎2025-04-09

The circuit does not look wrong however, not getting signal can also mean problems with layout. Have you checked with the antenna manufacturer on layout considerations? Have you followed guidelines in our hardware reference manual?

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Starboy-1427 · ‎2025-04-09

Thanks for the reply, I will check the layout considerations, my primary suspect was the layout.

I will follow the hardware documentation for consideration and make an iteration.

GalaxyQuest · ‎2025-04-09

I see you have included blocking cap on RF_IN which is good.

The RF_IN has a DC voltage, so if using a passive antenna, you need to block the DC bias.

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Starboy-1427 · ‎2025-04-09

Any other support material for the Design considerations will be helpful.

Please provide additional links for hardware design rules.

MHoll.2 · ‎2025-04-09

You are using a LNA (BGA535N6?), according to the data sheet, You have to connect the CTRL1 and CTRL2 input's.

Further more the data sheet suggests a serial inductor on the input side (for impedance maching).

Probably You could ask Taoglas for help on the impedance maching for the antenna.

The Bandpass filter used (B39162B4327P810?) seams to be only for the L1 Band, the LIV4F is a dual band receiver so You should use a dualband Bandpass filter. But this should give You anyway all the L1 band signals, so not the main problem at the monent.

Martin

Starboy-1427 · ‎2025-04-09

Could you please enlighten me on how to connect the control pins.

I will look into the inductance part for impedance matching surely.

MHoll.2 · ‎2025-04-09

Please consult the datasheet for Your LNA, if it is the BGA535N6 (the schema is blurry) then:

Starboy-1427 · ‎2025-04-09

Yes the LNA is BGA535N6, got the issue and solutions.

Thank you