  A new concept for a hybrid structure gaseous detector module with ion
backflow suppression for the time projection chamber in a future circular
collider is presented. It is a hybrid structure cascaded Gas Electron
Multiplier (GEM) with a Micromegas detector. Both Micromegas and GEM have the
capability to naturally reduce most of the ions produced in the amplification
region. The GEM also acts as the preamplifer device and increases gas gain
together with the Micromegas. Feasibility tests of the hybrid detector are
performed using an ${}^{55}$Fe X-ray source. The energy resolution is better
than 27% for 5.9 keV X-rays. It is demonstrated that a backflow ratio better
than 0.2% can be reached in the hybrid readout structure at a gain of 5000.
