In the Ansys Systems Tool Kit® (STK®) application, a -9999.99 value can appear in communications reports when any of the following happens:
- The transmitter and receiver do not have access (RF intervisibility) to each other. When a communications link does not exist between transmitters and receivers, the STK software returns a null in the communications link quality reports. Ensure that the objects (transmitters and receivers) have access.
- The transmitter and receiver antennas may not be appropriately pointing at each other. Gain represents how much the antenna amplifies a signal. A null occurs when waves radiating from an antenna destructively interfere with each other. The STK software represent this null with -9999.99 dB in the link budget report. To avoid this, you need to adjust the pointing of the antenna to obtain a valid gain in the direction of the link. You can do this by changing the pointing on a complex model antenna or by using a sensor to point. You need to do this on both sides of the link.
- The transmitter and receiver do not share the same bandwidth. If there is no overlap between the transmitter bandwidth and receiver bandwidth, the Rcvd Iso Power parameter will have a value of -9999.99.
- The propagation loss is not computing properly because of failure of one of the propagation models due to inputs being outside the bounds of the model, such as the Two Ray model or the TIREM model.
To learn more about modeling communications links in the STK application, please see the Introduction to STK Communications tutorial.
For more details about available link reports, please see the Evaluating Communications Links help page.
