Hi,
I am doing some experiments and find something interesting. Hope you can help me explain it.
1) I calculated the energy of received signal by summing the square of ADC samples' amplitude. I found that the energy is almost constant. I am quite curious what makes the received energy constant. In my view, the received energy should depend on the property of object (e.g. the range and RCS) and environment given the same tranmiting power.
2) Then I make an experiment to figure out what's the energy distribution on different ranges. The result shows that when there is only one weak object (e.g. a hand) in front of radar and no other strong reflections(e.g. no wall), the energy is concentrated in the near-zero range bins (0~3 range bins). Is this energy caused by the antenna coupling between Tx and Rx?
However, when there are strong reflections (e.g. reflection corner or walls), the energy is concentrated in the position of there objects and very samll energy in teh near-zero range bins. This is so strange, the energy in the near-zero range bins is varing in different environments and maybe that is what causes the constant received energy. I am not sure if it is the antenna coupling signature because in the previous thread someone said the antenna coupling should be constant given the same configuration.Could you please explain that?
Thanks,
William
