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Hello, I am trying to design a circuit using the MAX1472 ASK transmitter, at the 433MHz band. The image below shows the matching network necessary for 433MHZ and the general application schematic of the circuit.
I understand that this will work, but for my understanding I tried to simulate this matching network to understand how it works, and I can't seem to find how it transforms the output impedance to 50 ohms. The PAOUT pin is an open drain output, with all the external components handling impedance matching and the L1 doing DC biasing. I have set up the output as below and at 433MHz get an impedance of about 118 Ohms. I've also simulated with the AC source looking into the node where L3 and C7 meet, but am a little confused how this works. This is just for my understanding, as I am sure it will work. Thank you!
I understand that this will work, but for my understanding I tried to simulate this matching network to understand how it works, and I can't seem to find how it transforms the output impedance to 50 ohms. The PAOUT pin is an open drain output, with all the external components handling impedance matching and the L1 doing DC biasing. I have set up the output as below and at 433MHz get an impedance of about 118 Ohms. I've also simulated with the AC source looking into the node where L3 and C7 meet, but am a little confused how this works. This is just for my understanding, as I am sure it will work. Thank you!
