A current-mode MOSFET-C analog filter for the high-frequency band applications

Abstract

In this work, a novel current-mode filter is presented including a PMOS grounded capacitor and a metal insulator metal structure (MIM-cap). Proposed filter's cut-off frequency can be easily adjusted from 10 up to 35 MHz. The wide tuning range of the proposed filter is designed to cover the need of baseband filter in the high-frequency band and wireless applications such as CDMA, IEEE802.11a/g, IEEE 802.11b, and IEEE 802.11n. In addition, the proposed filter is designed by using a design methodology employing polynomial regressive models of small signal parameters of transistors to provide design accuracy as high as possible. Designed filter structure has layout with 52.1 mu m x 62.6 mu m chip area, and post-layout simulations are given extensively to prove performance of the filter. Furthermore, 1-dB compression point and IIP3 analyses are highlighted to observe linearity of band-pass output of the filter structure. Also, input-referred noise characteristics of the filter outputs are investigated to overcome thermal noise effects worsening the performance for a wide range of operating frequency interval. Provided results show that the proposed filter scheme brings a promising opportunity to designers for the high-frequency region operations.