Multi-loop antenna system for contactless applications

摘要

An antenna system suitable for use with contactless transaction devices, the antenna system including a reader, a primary loop antenna having a first end and a second end, each one of the first and second ends being coupled to the reader and at least one secondary loop antenna galvanically connected to the primary loop antenna at a single connection point and positioned with respect to the primary loop antenna so as to make capacitive coupling therebetween negligible.

主权项

1. An antenna system suitable for use with contactless transaction devices, said antenna system comprising:
a reader; a primary loop antenna having a first end and a second end, each one of said first and second ends being coupled to said reader such that there is a current return path between said primary loop antenna and said reader whereby said primary loop antenna presents an inductive load to said reader; and at least one secondary loop antenna galvanically connected to said primary loop antenna at a single connection point, said at least one secondary loop antenna being coupled to said reader at only a single one of its ends, such that establishment of a current path return between said secondary loop antenna and said reader is prevented, whereby said at least one secondary loop antenna does not present an inductive load to said reader, and said connection point between said secondary loop antenna and said primary loop antenna additionally serving as a connection point between said single end of said secondary loop antenna and said reader, wherein said secondary loop is closed on itself to form a closed loop.