Couplers in RF Blockset

What means return loss in Coupler block in RF Blockset? In Help write "Loss of signal power due to impedance mismatch of the Directional coupler" - what impedance tell about? I think, it cant be external load. May be there tell about mismatch output and input impedance in Coupler

Answer 1

[Shubham]

Hi Nikolay,

In the RF Blockset's "Coupler" block, the "Return loss" parameter refers to the signal power lost due to impedance mismatch between the coupler and the connected system. This mismatch is typically evaluated against a reference impedance of 50 ohms.

• Reference Impedance: The coupler's reference impedance can be set as a scalar or a positive three-tuple vector, with a default of 50 ohms. If the reference impedances of all ports differ, the model normalizes them to 50 ohms.
• Return Loss: This indicates the amount of signal reflected back to the source due to impedance mismatch. An infinite return loss indicates perfect impedance matching with no reflection, while a finite return loss suggests some reflection and an impedance mismatch. Higher return loss values indicate better matching and less signal reflection.

For more details, please refer to the MathWorks documentation on the "Coupler" block:

https://mathworks.com/help/releases/R2023a/simrf/ref/coupler.html

Hope this helps.