A-MOS Vs MOS Varactor

Dear all,

One of the paper shown that the Cmax/Cmin of the A-MOS Varactor is higher than the MOS varactor due to the MOS varactor presence of the OVERLAP capacitances between G and D-S. However, the overlap capacitance between G and D-S in the A-MOS also in precense. WHY this overlap capacitance in A-MOS will not contribute with the Cox (in parallel) and make the capacitance is higher?

Thanks

wccheng

What papers are yiu talking about?