I asked a question on the Electrical Engineering site regarding RSSI variations. I then flagged it for migration to Physics site since it seemed more relevant there. I deleted it after a few days since I thought I should do more research and then ask a more specific question. Consequently, I also deleted my Physics profile since I thought I would no longer use it again.
I now want to re post the same question since I have bonus reputation and can offer a bounty on it. I know I shouldn't have been so hasty with everything but here is a copy of the question I deleted. Would re posting it on Physics site be frowned upon?
I am doing some experiments to measure Received Signal Strength Indicator (RSSI) variations of a TX/RX pair of CC1120 modules when a person passes in between them. I constantly fire packets and measure RSSI.
I have mounted a Pulse W5017 antenna on both of them and it's facing vertically upwards on both nodes. The data sheet of this antenna can be found here:
After experimentation, I found out that when the nodes are placed on the ground, a breach between the nodes (a person passing between) creates a MUCH better dip in RSSI as compared to when the nodes are placed on a height, such as a workbench. See the graphs below:
The experiment was repeated to confirm the above observation.
The radiation patterns of the antennas are as shown below (from the datasheet):
By using the datasheet, and seeing the vertical pattern (since I am studying the effective height of placing the nodes), how does the observation match with the vertical radiation pattern? Before looking at the pattern, I had something of the following sort in mind:
A 3D view of the radiation pattern from both horizontal and vertical planes can be visualized as below:
Does it have something to do with the fact that when the nodes are placed on the ground, the lower lobe goes beneath the ground? Is it reflected above? What happens to the lower lobe?