Not working double LNA GPS Amplifier

Thread Starter

Kevil

Joined Jun 28, 2020
120
I have a problem with the GPS amplifier according to my own design, it does not work. There is no signal at the output.

L4 is the impedance matching of the antenna to 50 Ohm by autotune in SimSmith. It is strange that the current consumption is 2.8mA for a single-stage amplifier (Infineon Evaluation Board BGA524N6BOARDTOBO1) and only 3.6mA for my double-stage amplifier.

What could be wrong?

GPS_LNA_Schematic.png

UPR5008.jpg
 

Thread Starter

Kevil

Joined Jun 28, 2020
120
I connect SONY Li-Ion 4.2V battery to "+" and "-" port and connect two middle ports "3.3V" and "PON" togather. I measured the 3.3V on the pin by Voltmeter. The LNA ouput is connected to SparkFun GPS Breakout - ZOE-M8Q (Qwiic) and signal is monitored in u-Center sofware.

When I connect to ZOE-M8Q just the dipole wire antenna without the LNA:

u-Center_13.5_cm_Antenna_220107.png
 

Thread Starter

Kevil

Joined Jun 28, 2020
120
L3 is suggested output impedance matching of the B2611 Infineon SAW Filter. All parts has been reflow soldered by a professional company.

I will try to measure the amplifier gain characteristic by NanoVNA, waiting for SMA 20db and 40db attenuators.
 
Last edited:

dzenbo

Joined Aug 17, 2017
1
In my case even one stage amplifier doesn't work either. It only attenuate signal for 30 dB. Insane. Do you have some measurements?
 
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