Flexible radiofrequency filters based on highly conductive graphene assembly films

We demonstrate a flexible radiofrequency filter based on graphene assembly films with a high conductivity up to 106 S/m and a thickness of 10 μm. The flexible high-conductivity graphene film (HCGF) used in the filter has a fifth-order low-pass Chebyshev frequency response, and it operates at 3.6 GHz with a 0.82 dB in-band maximum insertion loss and 26.21 dB insertion loss at 5 GHz. Such performance observed in the HCGF-based flexible filters is comparable to that of commercial copper-based filters in passband and roll-off. The HCGF exhibits good mechanical flexibility even after 200 cycles of bending. Nearly no mechanical failure or performance degradation occurs during 20 cycles of 0°–50° bending for the flexible HCGF filter. Our results suggest that the flexible HCGF filter has good repetitive bending stability. This makes this type of filter suitable for future applications in flexible wireless communication.