This　paper　presents　a　novel　transparent　metasurface　that　combines　linear-to-circular　polarization　(LP-toCP)　conversion　with　phase　control.　The　metasurface　consists　of　a　Fabry-Perot　metasurface　for　phase　changes　and　an　asymmetric　chiral　metasurface　for　LP-to-CP　conversion.　By　stacking　these　two　metasurfaces　with　an　air　gap　and　optimizing　design　parameters,　the　dual-layer　metasurface　provides　both　LP-to-CP　conversion　and　phase　compensation　over　a　wide　bandwidth.　A　proof-of-concept　circularly　polarized　multi-beam　antenna　operating　at　13GHz　is　designed,　simulated,　fabricated,　and　tested　to　demonstrate　the　effectiveness　of　the　proposed　metasurface.　Results　show　that　the　antenna　can　generate　five　beams　over　a　scanning　range　of　±10°,　with　a　common　3-dB　axial　ratio　bandwidth　of　12.1-14.3　GHz　and　peak　gain　of　more　than　21dBi.　©　2023　European　Microwave　Association　(EuMA).