In this communication we present a concept of a partially reflective surface (PRS) antenna capable of independent beam-scanning and beamwidth dynamic control. The beamwidth is controlled by reconfiguring the PRS reflectivity via embedded varactor diodes, while the beam is steered by using a small phased array in the H-plane as a source antenna exciting the Fabry-Perot cavity. A fully operational prototype is fabricated and measured upon reconfiguration, demonstrating the viability of the concept and good agreement between simulated and measured results. The achieved beamwidth variation is from 18.7 degrees to 22.4 degrees, with the scanning range of 15 degrees and 20 degrees for the narrowest and the widest beamwidth, respectively.