I am reading the
microchip's LoRaWan Gateway manual. On Page
48, I got stuck at receiving side on the LoRaWan RF circuit. It looks like they have some sort of LC Low Pass Filter. I have used this online tool to calculate it's cutoff frequency. It gave me following reading:
Results: F = 3.3553e+9 [Hz] Z = 31.623 [Ohms]
I am not sure about the Resistor in between them. Please help me in verifying my interpretation of the circuit. The part of schematics that I am referring has been posted below:
Can someone help me in understanding the part of the circuit that have been encircled.
1257_RFINB goes to RF inputs (Single-ended) of two different RF transceiver chips (
SAW Filter and
SPF5043Z is LNA.