Sustainable Hemp-based Polycarbonate Substrates Enabling Low-Loss 5G and mmWave Electronic Systems

This work introduces a recyclable hemp-derived poly(cannabidiol-carbonate) (PCBDC) substrate as a sustainable low-loss material for 5G, microwave, and millimeter-wave electronics. PCBDC films were fabricated using a low-temperature process compatible with thin and flexible high-frequency packaging. Dielectric properties were extracted from microstrip ring resonator measurements up to 50 GHz, yielding εᵣ = 1.91 and tanδ = 0.0117 at 45 GHz. Identical resonators on BOROFLOAT® 33 glass demonstrated higher insertion loss under the same test conditions, while the measured PCBDC loss is also substantially lower than typical FR-4 values (tanδ ≈ 0.02 in the RF range). In addition to competitive electrical performance, PCBDC offers strong mechanical properties, and a recyclable and non-halogenated composition. Life-cycle assessment further indicates reduced environmental impacts relative to FR-4. These results position PCBDC as a practical and environmentally responsible substrate candidate for high-frequency packaging and interconnects in emerging 5G and mmWave systems.