This invention is a filter circuit having a filter element. A filter element
(4) is a parallel resonator circuit including a pair of first resonator
lines (19a) (19b) formed by a thick film forming technique
and a pair of second resonator lines (20a) (20b). As
the thickness of the pair of second resonator lines (20a) (20b)
is significantly reduced, the impedance ratio between the pair of second resonator
lines (20a) (20b) and the pair of first resonator lines
(19a) (19b) is increased. Therefore, the length of
these pairs of resonator lines (19a) (19b) (20a)
(20b) is reduced and miniaturization of the filter element is realized.
