# S21 measurements are missing ## Problem environment Antenna reflection is tuned for subgigaherz frequencies, and calibration benefits from S21 reflection testing. ## Steps to reproduce 1. Use a vector network analyser (VNA) 1. Test for reflection in anntenae 1. Measure S21 vector parameters ## Expected result The antenna chosen should be well calibrated according to S-parameters. ## Actual result S-parameters are unknown and measurement is missing. ## Severity level This is **low priority** because project requirements do not include antenna calibration.