Hi Kei,
I understand that you want to display ‘Receiver Antenna’s Gain Value (Gr)’ onto the Spectrum Analyzer in Simulink.
The block ‘Receiver Antenna Gain’ sends data of ‘single’ datatype to the ‘Receiver Antenna’ block, which leads to a data-type mismatch error as the ‘Receiver Antenna’ block expects the datatype to be ‘double’.
You can change the output datatype of ‘Receiver Antenna Gain’ block by modifying its Block Parameters as shown below:
Assuming the gain value ‘Gr’ to be present in the base workspace, you can display it in Spectrum Analyzer by using the ‘Constant’ block in Simulink as shown below:
The resulting waveforms in the Spectrum Analyzer are as follows:
Hope this helps!