Implementation of a Complex $\mathrm{g}_{\mathrm{m}}$-C Filter with one Type of $\mathrm{g}_{\mathrm{m}}$ Cell

In this paper, a technique to implement a complex
$\mathrm{g}_{\mathrm{m}}$
-C filter using “one type of gm cell” is presented. This technique simplifies the design and layout, and improves component matching which is important to achieve higher image rejection (IR). By using the introduced technique, the drop in IR due to mismatch of the coupling
$g_{m}$
cells will be reduced. All the needed
$g_{m}$
cells in the main filter and coupling paths will be an integer multiplication of a unit
$g_{m}$
cell. This simple and methodical approach can be combined with the post-layout parasitic adjustment for a simpler and more efficient design procedure.