Combined radio altimeter and doppler radar with surface-mountable antenna array and loop-back calibration

A method comprising:

• during a calibration procedure at a radio frequency (RF) unit:
• generating a calibration RF signal based on a digitized calibration signal;
• communicating the calibration RF signal to an antenna module via an electrical connector, wherein the antenna module is coupled to a surface of a vehicle and includes an antenna, and wherein the electrical connector is coupled to the antenna module and the RF unit;
• receiving a first bitstream from the antenna module via the electrical connector, wherein the first bitstream represents a sampled calibration signal;
• and
• determining a time delay associated with the electrical connector based on the digitized calibration signal and the first bitstream.

A method comprising:

• during a calibration procedure at an antenna module that is coupled to a surface of a vehicle and includes an antenna:
• receiving a calibration radio frequency (RF) signal from an RF unit via an electrical connector, wherein the electrical connector is coupled to the RF unit and the antenna module;
• sampling the calibration RF signal to generate a sampled digitized signal;
• and
• communicating the sampled digitized signal as a first bitstream to the RF unit via the electrical connector to enable generation, at the RF unit, of a time delay associated with the electrical connector.