I wonder if anyone can help me understand the TRF7970A's antenna hardware.
I attached an image with certain areas highlighted in color.
As I understand in the datasheet, the "blue area" is the Impedance Matching TX_Out circuit (50 ohms).
The "green area" is where should be placed the TRF7970A's antenna (Between 0 ohm resistors, the antenna should be connected). TRF7970A's antenna can be done step by step according to the document "Antenna Matching for the TRF7960 RFID Reader (SLOA135) ".
And here comes the part I do not understand: What role has the "red area" of the figure? Why is placed that part of the circuitry in the schematic TRF7970A? Why do not I see this part of the circuit in TRF7970EVM's hardware?