Design of analog equalizers for partial response detection in magnetic recording

Analog equalizers offer several advantages, such as high speed, small size, low power, and minimum delay, over sampled digital equalizers, (In this pa per, the phrase analog equalizer refers to continuous-time equalizers havin g poles and zeros.) However, because of their feedback nature, their design often involves extensive search procedures. Recently, an analytical design technique based on equation-error formulation was proposed. In this paper, we study this approach for partial response (PR) equalization and show tha t it is quite sensitive to the choice of timing phase and it could result i n quite suboptimal solution. We improve on it by using an iterative approac h similar to that of Steiglitz and McBride. We also present a thorough simu lation study to assess the performance loss incurred by low-order analog eq ualizers and produce performance charts that can be used for selecting the PR target for different channel characteristics. Application of this approa ch to multi-level decision feedback equalization detection is also discusse d.