IWR1642: FOV and range adjustment

Hello Darren,

Good question - there are a couple things that need to be clarified:

• The physical antenna characteristics defines the radiation pattern which of course cannot be changed in software. For the various EVMs users can consult the antenna database or the user's guide of their specific EVM for the radiation pattern. http://dev.ti.com/tirex/explore/node?node=AKu-aTm5FIcxlwZJU1pLBw__VLyFKFf__LATEST
• From the gain plots, we use 6dB beamwidth to equate to the characterized FOV for that antenna. This is the value that's reported in the table in the antenna database and in the user's guide for the EVM. 
• However, strictly speaking FOV is not a conventional or accurate specification for an antenna as it implies a binary threshold for "in view" or "out of view". Most users are familiar with FOV in the context of something similar to a camera where within the prescribed FOV a camera captures the same spatial range-angle area regardless of the composition of the objects in the scene. For example for a camera with a FOV of +/45 will capture a person or a car at 30 degrees equally and will fail to capture either object at 60 degrees.
• In contrast, for mmWave and antennas here the specified FoV relates to power and drop off. The practical effect is that for a given range and angle a highly reflective object may be detected while a low reflectivity object will not be detected -> there is a relationship between an object's characteristics and how far in range and angle it can be sensed. At 0 degrees where the antenna gain is the strongest there will be some max distance an object such as a person will be detected. As the angle increases (and the power drops off), the max range a person will be detected gets shorter and shorter. You can see some experimental results that illustrate this here: http://dev.ti.com/tirex/explore/node?node=AFJ57Xx4-1Hjsuqn1dMoFQ__VLyFKFf__LATEST (This is why there is the appearance of range dependency for FOV as suggested in the 2nd e2e thread)

So the short answer to your question - a customer can't change the antenna radiation pattern in software. Thus the max detectable angle they are observing now for their objects can not be increased. However as of SDK 3.x we support the ability to filter out points in software by range, velocity or angle (refer to the cfarFovCfg command in the SDK users guide for more details). This means that users can effectively decrease FOV and filter out points outside angles of interest but cannot increase the limits.

Amanda