| 摘要 |
A short axial-mode helical antenna (10) includes a winding (12) including a conductor (20) helically wound about an axis (8). A first portion (22) of the winding is wound with a first pitch (alpha) on a segment of a cone (41) having a smaller diameter (D1) at a plane (31) adjacent a ground plane (14), and a larger diameter (D2) at a second plane (32) parallel with the ground plane and remote therefrom. A second portion (24) of the winding (12) is wound with a second pitch (beta) on a segment of a second cone (42) coaxial with the first cone, and having its smaller diameter (D3) at a third plane (33) parallel with the first and second planes. The antenna provides higher gain than a straight uniform, tapered-end, continuous taped, or nonuniform-diameter helical antenna of equal length, and consequently has less mutual coupling when mounted in an array. |
