Radially distributed transverse filter

摘要

A radially distributed transverse filter includes a plurality of delay lines of substantially equal electric length sequentially coupled at a like plurality of nodes. The nodes are distributed equidistant from a common position, for example positioned at vertices of a polygon. A plurality of attenuators are distributed radially about the common position and coupled between the nodes and the common position. An adder is located substantially at the common position for summing the attenuator outputs. In this manner, the respective propagation delays of each tap are substantially similar, and imprecision due to variation in propagation delay is therefore mitigated and/or substantially eliminated. The invention has application to high-frequency digital and analog transverse filters, for example filters for equalizers used in Partial Response Maximum Likelihood (PRML) circuits employed in contemporary magnetic recording systems.