Circuit substrate for surface wave filter element

Abstract

Abstract PURPOSE:To improve frequency characteristics by further lowering a trap point on a frequency characteristics curve by preventing induction between an input terminal and output terminal by providing an intervenient part extending from a printed wiring part to the input terminal. CONSTITUTION:Circuit substrate 41 has as an earth part the part which includes printed wiring part 42 connected to signal input terminal 18, printed wiring parts 43 and 44 connected to output terminals 19 and 20, and earth terminals 17 and 21. Then, intervenient part 47 extending from wiring part 43 to terminal 18 is provided along straight line 46 connecting terminal 18 to terminal 19 at the diagonal position of terminal 18. Consequently, induction between terminals 18 and 19, and 20 is prevented and a signal from the output terminal is received by the differential amplifier to further lower trap points 37 and 38 on the frequency characteristic curve, so that the frequency characteristics can be improved.

Inventors

• 👤 Kiyobumi Yamashita

Bibliographic Details