Microstrip balun-antenna

Claim 2

A balun apparatus comprising: a substrate of dielectric material having first and second major surfaces; a microstrip transmission line including a microstrip conductor situated on said first surface and a groundplane conductor situated on the second surface below said microstrip conductor, said microstrip conductor and said ground plane conductor each having input and output ends; a split loop surface having first and second conductive arms providing a geometrical shape that closes on itself, said first and second arms each having a common end respectively coupled to the output end of said microstrip groundplane, said first and second arms forming a gap between the remaining ends of said arms a microstrip excitation element coupled to the output end of said microstrip transmission line, said element including sections having differing widths and being situated on said first surface and aligned substantially coextensive with said split loop structure therebelow.

Claim 3

A balun apparatus comprising: a substrate of dielectric material having first and second major surfaces; a microstrip transmission line including a microstrip conductor situated on said first surface and a groundplane conductor situated on the second surface below said microstrip conductor, said microstrip conductor and said ground plane conductor each having input and output ends; a split loop structure having first and second conductive arms providing a geometrical shape that closes on itself, said first and second arms each having a common end respectively coupled to the output end of said microstrip groundplane, said first and second arms forming a gap between the remaining ends of said arms a microstrip excitation element situated on said first surface and substantially overlaying said split loop structure, said element including sections having differing widths and extending from the output end of said microstrip transmission line above one of said arms, and across said gap, and overlaying a portion of the remaining arm.

Claim 4

A balun apparatus comprising: a substrate of dielectric material having first and second major surfaces; a microstrip transmission line including a microstrip conductor situated on said first surface and a groundplane conductor situated on the second surface below said microstrip conductor, said microstrip conductor and said ground plane conductor each having input and output ends; a split loop structure having first and second conductive arms providing a geometrical shape that closes on itself, said first and second arms each having a common end respectively coupled to the output end of said microstrip groundplane, said first and second arms forming a gap between the remaining ends of said arms a microstrip excitation element situated on said first surface and substantially overlaying said split loop structure, said element including sections having differing widths and extending from the output end of said microstrip transmission line above one of said arms, and across said gap, and overlaying a portion of the remaining arm.

Claim 5

A balun apparatus comprising: a substrate of dielectric material having first and second major surfaces; a microstrip transmission line including a microstrip conductor situated on said first surface and a groundplane conductor situated on the second surface below said microstrip conductor, said microstrip conductor and said ground plane conductor each having input and output ends; a split loop structure having first and second conductive arms providing a geometrical shape that closes on itself, said first and second arms each having common end respectively coupled to the output end of said microstrip groundplane, said first and second arms forming a gap between the remaining ends of said arms a microstrip loop element situated on said first surface and substantially overlaying said split loop structure, said element being coupled to the output of said microstrip transmission line, said element including sections having differing widths and being coupled to one of the arms of said split loop structure at a location adjacent said gap.

Claim 6

A balun apparatus comprising: a substrate of dielectric material having first and second major surfaces; a microstrip transmission line including a microstrip conductor situated on said first surface and a groundplane conductor situated on the second surface below said microstrip conductor, said microstrip conductor and said ground plane conductor each having input and output ends; a split loop structure having first and second conductive arms providing a geometrical shape that closes on itself, said first and second arms each having common end respectively coupled to the output end of said microstrip groundplane, said first and second arms forming a gap between the remaining ends of said arms a microstrip loop element situated on said first surface and substantially overlaying said split loop structure, said element being coupled to the output of said microstrip transmission line, said element including sections having differing widths and being coupled to one of the arms of said split loop structure at a location adjacent said gap.