Is there away to embed an antenna calibration circuit, over its transmit band, without great expense? I was thinking circulator and power detector to measure reflective power.
Sure! You could use a circulator, or a directional coupler to measure reflection and auto-tune to antenna for best VSWR. This is actually being done in some amateur radio antenna tuners. An on-the-fly control system would be a bit ugly since it's difficult to find a minimum and then tune to it. It's probably simpler to determine the best tuning over the band and record it in the nonvolatile memory of a microcontroller then call up the results as needed.
Is there away to embed an antenna calibration circuit, over its transmit band, without great expense? I was thinking circulator and power detector to measure reflective power.
Sure! You could use a circulator, or a directional coupler to measure reflection and auto-tune to antenna for best VSWR. This is actually being done in some amateur radio antenna tuners. An on-the-fly control system would be a bit ugly since it's difficult to find a minimum and then tune to it. It's probably simpler to determine the best tuning over the band and record it in the nonvolatile memory of a microcontroller then call up the results as needed.
I've been doing a similar measurement on a tiny antenna at 5GHz. It wasn't easy but eventually got a return loss of 17dB.
17 dB is impressive at that frequency. Well done!