Hybrid　analog　and　digital　(HAD)　beamforming　has　been　recently　receiving　considerable　deserved　attention　for　practical　implementation　on　the　large-scale　antenna　systems.　Compared　to　fully-digital　beamforming,　partially-connected　HAD　beamforming　can　significantly　reduce　the　hardware　cost,　complexity,　and　power　consumption.　This　paper　aims　to　mitigate　interference　and　increase　robustness　against　direction-of-arrival　(DOA)　mismatch　along　with　lowering　hardware　complexity,　cost,　and　power　dissipation.　To　achieve　these　goals,　a　novel　robust　HAD　beamforming　receiver　with　partially-connected　structure　is　proposed.　It　is　based　on　methods　of　an　improved　bat　algorithm　(I-BA)　and　robust　adaptive　beamformers　(RABs)　in　the　digital　domain.　Since　most　of　the　RAB　methods　are　sensitive　to　the　DOA　mismatch　and　depending　on　the　complex　weights　which　lead　to　an　expensive　receiver,　the　I-BA　is　proposed.　In　the　analog　part,　analog　phase　alignment　by　linear　searching　(APALS)　with　sufficiently　fine　grid　points　is　employed　to　optimize　the　analog　beamforming　matrix.　The　performance　of　the　proposed　I-BA　is　assessed　using　MATLAB　simulation　and　compared　with　BA,　and　particle　swarm　optimization　(PSO)　algorithms.　It　shows　better　performance　in　terms　of　convergence　speed,　stability,　and　convergence　rate.　Besides,　the　proposed　hybrid　I-BA-APALS　approach　showed　better　performance　compared　to　other　proposed　robust　hybrid　techniques,　i.e.,　diagonal　loading　(DL)　APALS　(DL-APALS)　and　DL　spatial　matched　filter　(SMF)　APALS　(DL-SMF-APALS).　©　2013　IEEE.