On Fri, Feb 5, 2021 at 03:30 PM, Clifford Heath wrote:
When I redesigned the HackRF antenna protection, I removed the useless TVS, a
bi-directional 15V type (that will only activate after everything in the
HackRF is already dead), and instead used Skyworks Limiter Diodes
SMP1330-085LF.
In the case of the HackRF, I need to protect the LNA from any excursions above
13dBm, but the transmitter and mixer inputs are a bit more robust, so I used
three of these diodes.
Clifford - Just took a look at your schematic.
--- I see you reverse biased one of the diodes to Vaa (3V) and the other to ground. Why not both to ground?
---- It look like you used 10 k resistors instead of RF chokes like the Skyworks app note. Any particular reason?
---- How much RF power can you now safely inject without damage using this new circuit.
Thanks - Roger
Roger Need