What's the purpose of this capacitor here? I certainly don't think it's for decoupling but maybe bypassing? I presume we don't want any of the amplified RF which might have sneaked by the inductor getting back into the GNSS module.
- Antenna is tuned for GPS / GLONASS at 1590 MHz.
- Maximum input power at RF_IN will be 15dBm.
- VCC_RF typical current rating from datasheet is 50 mA (Max 100 mA). - I dont have specifications from Active antenna yet.
- VCC_RF typical is about 3.2 volts for this application.
- The inductor I'm using is the recommended (in hardware integration manual provided by supplier) 27nH (LQG15HS27NJ02) with impedance at GPS freq > 500 ohms.
- There is no recommended value for the capacitor however.
*Note: The recommended 10 ohm R bias resistor is relatively beefy at 1/4 watt.
What's the best way to determine it's capacitance / parameters?