A Second-Order Bandpass Filter With 1.6-dB Insertion Loss and 47-dB Upper-Stopband Suppression in 45-nm SOI CMOS Technology
Xinran Yang, He Zhu, Yi Zhao, Zubin Chen, Feng Sun, Xi Zhu
Abstract
In this letter, a design methodology is presented to generate an upper-stopband transmission zero (TZ) for a bandpass filter (BPF) for improving the selectivity and the stopband suppression performance. Using this method, the TZ can be generated in a very flexible way. As proof of concept, a 30-GHz <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${2}^{\text {nd}}-$ </tex-math></inline-formula>order bandpass filter (BPF) is fabricated in 45-nm SOI CMOS technology. The measured insertion loss is less than 1.6 dB, and the upper-stopband suppression is greater than 45 dB. Besides, the footprint, excluding the pads, is only 0.046 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>.