CMOS製程實現2.4GHz低雜訊放大器整合具有三個零點的主動電感帶濾波器

2.4-GHz CMOS Active-Inductor Bandpass Filter with Three Transmission Zeros and a Precedent LNA

郭毓霖；孟慶宗；吳彥鋒；黃國威

國家奈米元件實驗室奈米通訊

25卷3期（2018 / 09 / 01）

9 - 13

繁體中文

這項研究為CMOS技術整合RF接收器與帶通濾波器帶來一盞光明。晶片裡實現的主動率波器通常具有高Q值、低入射損耗、小面積的特性，並在其之前加上一低雜訊放大器可以用來取代現今常見的表面聲波濾波器。比起被動率波器，使用主動率波器通常會導致很差的雜訊指數和線性度，然而可以在主動濾波器之前加上低雜訊放大器來抑制整體雜訊指數。本研究所提出的具可調式電感的主動濾波器是使用0.18um CMOS製程來實現的。再加上一低雜訊放大器後，整體雜訊指數只有4.9dB。此外，此低雜訊放大器整合主動電感濾波器具有三的帶外零點可以來來濾除2.4GHz帶外雜訊。

This study has shed light on the integration of an RF bandpass filter in the RF receiver using CMOS technology. An on-chip active filter with characteristics of high-Q, low insertion loss and small size after the LNA (low noise amplifier) is employed to replace the topology of a traditional off-chip SAW (surface acoustic wave) filter in front of an LNA. It is well known that an active filter leads to a bad noise figure and linearity than the passive filter. However, the high noise figure of an active-inductor bandpass filter is suppressed by the precedent LNA. The demonstrated tunable active-inductor filter is implemented using 0.18 μm CMOS technology. After locating the active filter behind a low noise amplifier, the measured noise figure is 4.9 dB. Moreover, the demonstrated LNA + active inductor filter has three transmission zeros to reject the out-of-band signals in the congested 2.4 GHz band.