closely space the transmission line from the ground plane is an important factor to consider in selecting the shape of wedge portion 61 it should be appreciated that balun 60 includes conductive vias 32 u2032 which may be the same as or similar to conductive vias 32 described above in conjunction with fig1 1b it should also be appreciated that balun 60 could benefit from the double via structure described above in conjunction with fig1 i e the use of two vias such as vias 32 34 in fig1 balun 60 also includes vias 40 u2032 which may be the same as or similar to vias 40 described above in conjunction with fig1 1c i e provided using a backdrill and fill technique as described in conjunction with fig1 1b it should be noted that portions of conductor 62 have been removed to expose dielectric channels 64 the purpose of channel 64 is produce strong coplanar coupler realizing the benefits mentioned above referring now to fig4 4b in which like elements of fig1 3b are provided having like reference designations throughout the several views a balun 70 further includes a plurality of ground blocks here four ground blocks 72 a 72 d generally denoted 72 with a respective one of ground blocks 72 a 72 d disposed in a respective one of each.