This Is AuburnElectronic Theses and Dissertations

Design of Reconfigurable Baseband Filter




Jin, Xin

Type of Degree



Electrical Engineering


With the rapid development of worldwide wireless communication networks, mobile terminal devices compatible for multi-standard and various applications are needed. Software defined radio is a suitable answer to those demand. Baseband filter is one of the key building blocks in this device. And the baseband filter designed with tunable cutoff frequency gains a lot of popularity in recent years. A linear, reconfigurable fully differential CMOS transconductance-C filter is presented in this paper. The filter is implemented in 0.13um CMOS technology. It provides inverse-Chebyshev response and the cutoff frequency tuning range of the filter is from 4MHz to 40MHz. The transconductor adopts a folded-cascode structure and using gain boosting technique in the output stage to provide high output impedance. The input stage uses cross-coupled differential pair with bias offset to achieve high linearity. To be able to achieve the tuning capability of the filter, a floating voltage source with tunable value is employed. Cutoff frequency can be tuned by varying the floating voltage.