▎ 摘　　要

NOVELTY - The filter has a capacitor whose end is connected with a grid electrode and another end is connected with a ground terminal. An input end of another capacitor is connected in parallel with a gate electrode of a graphene transistor, and an output end is connected with a drain electrode of the graphene transistor. A transition layer is formed on a substrate, and a metal wiring layer and an interlayer medium layer are arranged on the transition layer. A channel layer i.e. graphene thin film, is formed on a source electrode, drain electrode and the grid electrode. USE - Envelope detection filter. ADVANTAGE - The filter has simple circuit structure. DETAILED DESCRIPTION - The transition layer and the interlayer medium layer are formed by silicon dioxide. DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of an envelope detection filter.