應用於遠距照護無線通訊系統之可調頻寬與自動增益調整類比前端電路

本論文提出一個可調頻寬與自動增益調整類比前端電路，包含了三階橢圓低通濾波器與自動增益可調電路來實現整體架構，應用於遠距照護無線通訊系統。論文中以轉導放大器為基本架構，進而發展出轉導可調式放大器，濾波器的架構採用轉導放大器與電容來構成橢圓濾波器的係數，而濾波器的截止頻率經由轉導值切換陣列可以四次切換，並以開關控制訊號選擇轉導值。濾波器的通道頻寬可調範圍分別為0.6 / 1 / 2 / 5 百萬赫茲。所提出的自動增益可調電路由可調增益放大器、峰值感測器、栓鎖器延遲三個主要的電路構成，可調增益的方式由調整時域式可調增益放大器電路中二個時脈的時間差所形成，而時域式可調增益放大器所產生的輸出電壓可以直接給下一級ADC使用。此電路以TSMC 0.18-μm CMOS 製程來實現，在單電源操作電壓為+1.8伏特，總功率消耗約6.45~6.73 mW，晶片面積為2.186x1.464 mm2。

關鍵字

可調增益放大器；轉導放大器；頻寬可調；橢圓低通濾波器；自動增益可調電路

並列摘要

A programmable-bandwidth analog front-end with automatic gain control (AGC) is proposed in this work. The 3rd-order elliptic lowpass filter is implemented by using programmable operational transconductance amplifiers (OTAs). The cutoff frequency of the filter is tunable from 0.6MHz to 5MHz for Zigbee telecare systems. A novel peak detector technique is proposed to design the variable gain amplifier (VGA). The voltage gain is adjustable by varying the phase delay between the clocks of two AGC systems. The power consumption is 6.45~6.73 mW over the tuning range in a TSMC 0.18-μm CMOS process with a single 1.8V power supply.

並列關鍵字

transconductance ； OTA ； bandwidth tunable ； Elliptic lowpass filter ； Variable Gain Amplifier ； auto gain control

參考文獻

[7] Phillip E. Allen, Douglas R. Holberg, and Allen, CMOS Analog Circuit Design, OXFORD, 2002.

[9] Steve Winder, Analog and Digital Filter Design, Newnes, Oct. 2002.

[10] “A Basic Introduction to Filters – Active, Passive and Switched-Capacitor”, Application Note AN779, National Semiconductor Corporation, 1991.

[12] Behzad Razavi, Design of Analog CMOS Integrated Circuits, McGraw-Hill, August 2000.

[13] G. Fischer and G. S. Moschytz, “On the Frequency Limitations of SC Filters,” IEEE J. of Solid-State Circuits, vol. SC-19, Aug. 1984.

國際替代計量

應用於遠距照護無線通訊系統之可調頻寬與自動增益調整類比前端電路

未授權

主題瀏覽