High‐order realisation of MOSFET‐only band‐pass filters for RF applications

Abstract

The authors present two new metal oxide semiconductor field effect transistor (MOSFET)-only second-order voltage and transadmittance-mode band-pass filters (BPFs) employing only five transistors without using any passive elements such as a resistor, a capacitor, and an inductor. As a result, both proposed circuits possess low-power consumption and occupy small chip area. The first proposed filter enjoys low output impedance and offset cancellation for voltage-mode operation while the second proposed filter has low supply voltage. The centre frequency of both proposed filters can be electronically tuned by varying biasing voltage. To demonstrate the performance of the proposed filters, effects of output transconductance of transistors have been investigated and equations of input referred noise have been obtained. Furthermore, fourth-order voltage and transadmittance-mode BPF which is derived the first proposed filter is presented and its simulation results are given. All proposed filters are laid-out in the Cadence environment using Taiwan semiconductor manufacturing company (TSMC) 0.18 µm complementary metal oxide semiconductor (CMOS) technology parameters. The required chip area of the fourth-order voltage and transadmittance-mode band-pass filter is 1100 μm 2 and the power consumption is about 436 µW.

A current‐mode MOSFET‐C analog filter for the high‐frequency band applications

“…[6][7][8][9][24][25][26][27] Also, intrinsic C gs capacitances of them give rise to MOS-only designs. [28][29][30][31][32][33][34] Even though they bring low power consumption with small chip area, nonlinear intrinsic capacitances of the MOS devices deteriorate adjustability of the filter structure.…”

“…Another attempt to approach high transconductance values with acceptable linearity is to use MOS transistors as transconductors 6–9,24–27 . Also, intrinsic C gs capacitances of them give rise to MOS‐only designs 28–34 . Even though they bring low power consumption with small chip area, nonlinear intrinsic capacitances of the MOS devices deteriorate adjustability of the filter structure.…”