A transistor-only low-pass filter with adjustable bias and small phase shift at high frequencies

Abstract

A third-order, low-pass, transistor-only filter with a small phase shift at high frequency and an adjustable cutoff frequency is presented. This low-pass filter overcomes the structure limit of the filter previously reported and achieves the same frequency response. It has an adjustable bias voltage which makes it possible to change its cutoff frequency.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>