After Dark Characterization

A project log for 1.420 GHz Antenna

With on-board matching network.

Robert RouquetteRobert Rouquette 08/13/2020 at 16:240 Comments

I've completed characterization of the "after dark" prototype boards, and the FR4 material has significantly lower relative permittivity than the standard purple boards.

TL LengthTL 1/2 Wave ResonanceResonance Period
0.0254 m 2.920 GHz0.3425 ns
0.0381 m2.040 GHz0.4902 ns
0.0508 m1.553 GHz0.6439 ns

Performing a regression between the length and resonance period yields a fairly clean result:

This indicates that the phase velocity is 0.1685 m / ns which results in a relative permittivity of 3.164:

In summary: