公开(公告)号：GB2282487B

公开(公告)日：1997-04-09

申请号：GB9421721

申请日：1994-02-14

Applicant: MOTOROLA INC

Inventor： MOLLER PAUL J ,  SWINGHAMMER PATRICK A ,  SCHWARTZ MARK W

IPC: H01Q1/24 ,  H01Q1/36 ,  H01Q9/36 ,  H01Q9/40 ,  H04Q1/24

Abstract: An antenna assembly, and associated method, for a radio, such as a portable radiotelephone, which is of minimal physical dimensions and which is operable over a wide range of frequencies. A length of wire is helically-shaped and includes at least a portion of a winding. A capacitive top-hat is positioned at an end portion of the wire. By increasing the number of windings of the wire, the height of the antenna assembly is reduced, but such reduction also reduces the size of the bandwidth of frequencies over which the antenna assembly is operable. Increase in the size of the surface area of the capacitive top-hat increases the size of the bandwidth over which the antenna assembly is operable. Selection of the top-hat size and the number of windings permits beth physical dimensions of the antenna assembly and the size of the bandwidth to be selected.

公开(公告)号：GB2282487A

公开(公告)日：1995-04-05

申请号：GB9421721

申请日：1994-02-14

Applicant: MOTOROLA INC

Inventor： MOLLER PAUL J ,  SWINGHAMMER PATRICK A ,  SCHWARTZ MARK W

IPC: H01Q1/24 ,  H01Q1/36 ,  H01Q9/36 ,  H01Q9/40

Abstract: An antenna assembly (100), and associated method, for a radio, such as a portable radiotelephone, which is of minimal physical dimensions and which is operable over a wide range of frequencies. A length of wire (106) is helically-shaped and includes at least a portion of winding. A capacitive top-hat (136) is positioned at an end portion of the wire. By increasing the number of windings of the wire (106), the height of the antenna assembly is reduced, but such reduction also reduces the size of the bandwidth of frequencies over which the antenna assembly is operable. Increase in the size of the surface area of the capacitive top-hat (136) increases the size of the bandwidth over which the assembly is operable. Selection of the top-hat size and the number of windings permits both physical dimensions of the antenna assembly and the size of the bandwidth to be selected.