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M20057-1 GNSS Active Antenna Issue with AT1 & AT2 connected to GND with 0 ohm res.
I am using Quectel L-70 GPS module with M20057-1 part. My RF path in tuned to 50 ohm Impedance and working very fine with external antenna. We are unable to receive any data ( like HDOP,PDOP,3D Index etc) with this antenna. I have connected 0 ohm res. to AT1 & AT2 pins and followed same layout guidelines as mentioned in datasheet.

What could be potential issue with this antenna that am not able to receive any data ?

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Hello Viral Vasa,

It sounds like your M20057 module is not tuned properly to the GPS frequency. AT2 should start at 1.8nH not a 0 ohm resistor AT1 can stay at 0 ohm and then continue to adjust AT2 until the signal gets better.  There is also a capacitor across pin 4 and pin 6 that can be adjusted up or down a couple of values to see if this improve the TTFF.
If you are still having problems please contact me at and we can discuss your design further.

Best regards,

Geoff S.

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