Plain-language answer: Front-to-back ratio compares response in the intended forward direction with response directly behind the antenna, usually in decibels.
Why it changes the result
It helps judge rear rejection but says nothing by itself about sidelobes, front-to-side response, gain, bandwidth, or reflections.
What to verify
Read the exact azimuth pattern at the operating frequency and verify orientation with a stable signal.
The common mistake
Using front-to-back ratio as a substitute for the whole pattern.
Complete-system boundary
Match the exact radiator, feed system, return path, frequency, height, orientation, and environment. Connector or thread fit does not establish electrical compatibility, structural capacity, or safe operation.
