Title :
RF bandpass filter design using capacitive degeneration
Author :
Valdes-Garcia, Alberto ; Silva-Martinez, Jose ; Sánchez-Sinencio, Edgar
Author_Institution :
Dept. of Electr. Eng., Texas A & M Univ., College Station, TX
Abstract :
This work proposes the use of a capacitively degenerated transconductor to construct an RF bandpass filter. The fundamental theoretical elements for the application of this technique are provided. First, the impedance seen from the source/emitter of a transistor with capacitive degeneration and an LC tank connected at its gate/base is analyzed. The conditions under which this impedance exhibits a large value in a narrow bandwidth are obtained showing good agreement between theoretical and simulated results. A general RF filter structure based on the analyzed active resonant cell is introduced and described with a macromodel. A sample 5.2 GHz bandpass filter is designed for a SiGe BiCMOS 0.25 mum process. Simulation results for the designed RF filter show S21 > 6dB, Q > 20 consuming 1 mA from a 2.5 V supply
Keywords :
BiCMOS integrated circuits; Ge-Si alloys; band-pass filters; integrated circuit design; radiofrequency filters; transistor circuits; 0.25 micron; 1 mA; 2.5 V; 5.2 GHz; LC tank; RF bandpass filter; RF filter structure; SiGe BiCMOS process; active resonant cell; capacitive degeneration; source/emitter impedance; transconductor; transistor; Band pass filters; BiCMOS integrated circuits; Bipolar transistors; Electronic mail; Equations; Impedance; Inductors; Radio frequency; Resonance; Voltage-controlled oscillators;
Conference_Titel :
Circuits and Systems, 2005. 48th Midwest Symposium on
Conference_Location :
Covington, KY
Print_ISBN :
0-7803-9197-7
DOI :
10.1109/MWSCAS.2005.1594221
