Patent ID: 8862063

Claim:
An apparatus comprising: a substrate comprising a signal line; a first defected ground structure and a second defected ground structure printed onto the substrate to form a first ground plane, wherein the first and second defected ground structures are configured to shift a phase of an RF signal, wherein the first defected ground structure includes a short stem dumbbell structure and the second defected ground structure includes a long stem dumbbell structure, and wherein the first defected ground structure is nested within the second defected ground structure; a user interface configured to receive dimensions of the first and second defected ground structures, a target beam tilt value for a base station antenna, and a target phase shift; and a second ground plane configured to removably and selectively cover a portion of at least one of the first and second defected ground structures, thereby adjusting the phase shift of the RF signal, and the adjusting being based at least in part on the received dimensions, target beam tilt value, and target phase shift.