The feasibility of using the SOI-MOSFET as a quasi-diode to replace the Schottky-barrier diode in the Schenkel circuit is examined by device simulations primarily and experiments partly. Practical expressions of boost-up efficiency for d. c. condition and a. c. condition are proposed and are examined by simulations. It is shown that the SOI-MOSFET-based quasi-diode is a promising device for the Schenkel circuit because high boost-up efficiency can be gained easily. An a. c. analysis indicates that the fully-depleted condition should hold to suppress the floating-body effect for GHz-level RF applications of a quasi-diode.