A bond-wire transformer (200, 300, 400, 500, 600) for an RF circuit comprising: a substrate being a semiconductor die comprising a plurality of metal layers including a top-level metal layer and a next lowest metal layer (N-1), which substrate has a pair of primary terminals (14, 16) and a pair of secondary terminals (24, 26), wherein a region of one of the plurality of metal layers is defined as a shield layer, wherein the shield layer is operably coupled to a ground potential, a primary circuit comprising primary bond-wires (12, 32) electrically coupled in series between the pair of primary terminals (14, 16), a first of the primary bond-wires having a different maximum spacing from a major surface of the substrate than a second of the primary bond-wires, and a secondary circuit comprising secondary bond-wires (22, 34) electrically coupled in series between the pair of secondary terminals (24, 26), a first of the secondary bond-wires having a different maximum spacing from a major surface of the substrate than a second of the secondary bond-wires, wherein the first terminal (14, 24) of said pairs of terminals is defined in the top-level metal layer and the second terminal (16, 26) of said pairs of terminals is defined in the next lowest metal layer (N-1), wherein the primary circuit comprises at least one primary loop having a pair of primary bond-wires (12, 32), each pair consisting of a first and a second primary bond-wire, which first primary bond-wire is routed directly over the second primary bond wire without making direct contact, wherein the secondary circuit comprises at least one secondary loop having a pair of secondary bond-wires (22, 34), each pair consisting of a first and a second secondary bond-wire, which first secondary bond-wire is routed directly over the second secondary bond wire without making direct contact.. a substrate being a semiconductor die comprising a plurality of metal layers including a top-level metal layer and a next lowest metal layer (N-1), which substrate has a pair of primary terminals (14, 16) and a pair of secondary terminals (24, 26), wherein a region of one of the plurality of metal layers is defined as a shield layer, wherein the shield layer is operably coupled to a ground potential, a primary circuit comprising primary bond-wires (12, 32) electrically coupled in series between the pair of primary terminals (14, 16), a first of the primary bond-wires having a different maximum spacing from a major surface of the substrate than a second of the primary bond-wires, and a secondary circuit comprising secondary bond-wires (22, 34) electrically coupled in series between the pair of secondary terminals (24, 26), a first of the secondary bond-wires having a different maximum spacing from a major surface of the substrate than a second of the secondary bond-wires, wherein the first terminal (14, 24) of said pairs of terminals is defined in the top-level metal layer and the second terminal (16, 26) of said pairs of terminals is defined in the next lowest metal layer (N-1), wherein the primary circuit comprises at least one primary loop having a pair of primary bond-wires (12, 32), each pair consisting of a first and a second primary bond-wire, which first primary bond-wire is routed directly over the second primary bond wire without making direct contact, wherein the secondary circuit comprises at least one secondary loop having a pair of secondary bond-wires (22, 34), each pair consisting of a first and a second secondary bond-wire, which first secondary bond-wire is routed directly over the second secondary bond wire without making direct contact..