Abstract
It is theoretically predicted that drift-cyclotron instabilities driven by density gradient are feedback stabilized by modulated electron sources immersed within the plasma. The feedback source term included in the Vlasov equation is simply approximated by a distributed source. The fluid-like unstable modes with and without finite kZ, and the unstable modes due to the resonance between the ions and the perturbations with finite kZ are found to be suppressed simultaneously by negative feedback with gain in certain ranges, where k is the component of the wave vector along the magnetic field. It is also shown that the stable modes without feedback remain stable by negative feedback, and are destabilized or remain stable by positive feedback.