Specific receptors on cell membranes that react with PLATELET-DERIVED GROWTH FACTOR, its analogs, or antagonists. The alpha PDGF receptor (receptor, platelet-derived growth factor alpha) and the beta PDGF receptor (receptor, platelet-derived growth factor beta) are the two principle types of PDGF receptors. Activation of the protein-tyrosine kinase activity of the receptors occurs by ligand-induced dimerization or heterodimerization of PDGF receptor types.