The invention discloses a
silicon-based multi-layer cavity filter, which is formed by superposing more than two medium
layers up and down, wherein a through hole is formed in each medium layer; an internal wall
metal layer which is formed by using a
silicon micro-
machining technology is arranged on an internal wall of the through hole; an intermediate
metal layer which is formed by using the
silicon micro-
machining technology is arranged between the two adjacent medium
layers; an inter-stage
coupling window is arranged on the intermediate
metal layer; an upper surface of a top medium layer and a lower surface of a bottom medium layer are respectively provided with a surface metal layer which is formed by using the silicon micro-
machining technology; a metal layer which is contacted with the upper and lower surfaces of each medium layer and an internal wall metal layer form a
resonant cavity; and an input tap lead is arranged on one
resonant cavity, and an output tap lead is arranged on another
resonant cavity. The silicon-based multi-layer cavity filter is small in size, has a shielding function, can meet the accuracy requirement of
microwave /
millimeter wave frequency band, and is free from encapsulation, good in device consistency, compatible with an
integrated circuit process, easy to implement
system integration and convenient to assemble and debug.