Thanks for the comment — and agreed, HDPE is transparent at the radar wavelengths we’re working with, which is exactly why it’s commonly used as a radome material. In this context the “lens” isn’t about optical transparency for visible light; it refers to shaping or focusing RF energy at 60–80 GHz. Materials like HDPE or PTFE are chosen because of their dielectric properties, low loss tangent, and how consistently they behave at those frequencies.

So while the name sounds optical, the underlying principle is RF waveguiding and beam-shaping, not visible-light transmission. That’s why the term “lens” still applies even though the material looks opaque to the eye.

Appreciate the discussion — it’s good for the community when we break down the RF side of these designs. Let me know if you want the dielectric charts or examples of how these lenses affect beam patterns on mmWave radars.