Graphene effects on the RF interdigital capacitors

In this study, the electrical characteristics of interdigital capacitors with single-layer and multi-layer graphene are compared and analyzed in the microwave region. In equivalent circuit, a capacitor coupled with graphene shows the clear difference in electrical components such as resistance, inductance, and capacitance. In particular, for the capacitor with single-layer graphene, additional inductance and resistance is occurred and the electrode resistance is also increased. Meanwhile, the self-resonance frequency of capacitor is shifted toward lower frequency region and its transmitted characteristic is considerably improved at frequency ranging from 0.4 to 4 GHz. The electrical characteristics of the capacitor with multi-layer graphene are somewhat different than the bare capacitor. In conclusion, we can confirm that single-layer graphene greatly influences the electrical characteristics and performances of interdigital capacitor compared to multi-layer graphene.