The differences between FR-4 and F4B in terms of high-frequency loss are as follows:
Comparison of Dielectric Loss Factor (Df) FR-4: At 10 GHz, the dielectric loss factor (Df) of standard FR-4 is approximately 0.018–0.035, while that of low-loss FR-4 specifically designed for high frequencies can be reduced to 0.008–0.010. F4B: At 10 GHz, the Df of F4B is as low as 0.0013–0.0017 (e.g., 0.0013 for F4BM265 and 0.0017 […]