Reduction of Effect due to Parasitics in Integrated Wave Filters

Abstract

Design of integrated wave filters with effect due to parasitics relaxed is proposed. Improvement of frequency characteristics is achieved by using current-mode circuits and appropriately transforming the transfer function of a wave unit. Circuitry of two building blocks one of which follows another in a wave filter is also simplified for eliminating parasitics. Moreover small-signal analysis leads to a design guidance that the gate-source bias voltage of a MOSFET which operates as an equivalent resistor should be large. Two wave filters are designed based on the guidance as examples and validity of the guidance is verified with SPICE.