Radio frequency tag with miniaturized resonant antenna
First Claim
1. An RF transponder including a front end, signal processor, and a memory, said transponder comprising:
- a substrate;
an RF integrated circuit disposed on said substrate;
an antenna provided on said substrate and coupled to said RF integrated circuit, said antenna having an electrical length that is greater than a maximum length dimension of said substrate and having an input impedance including a real component and a reactive component;
at least one loading bar spaced from said antenna, wherein at least one of a bar length, bar width, spacing and number of bars of said at least one loading bar is selectively adjusted to reduce said real component of said input impedance of said antenna such that sufficient voltage is transmitted to said front end to operate said front end and said signal processor of said transponder; and
at least one tuning stub coupled to said antenna, wherein at least one of a stub length, stub conductor width, and stub conductor spacing is selectively adjusted to change said reactive component of said input impedance of said antenna such that said reactive component of said antenna substantially equals a negative magnitude of a reactive part of an input impedance of said front end.
3 Assignments
0 Petitions
Accused Products
Abstract
An RF transponder is provided with a miniature resonant antenna that can fit on a small form factor the size of a button or coin. More particularly, the RF transponder comprises a substrate and an RF integrated circuit disposed thereon. An antenna is provided on the substrate and is electrically connected to the RF integrated circuit. The antenna has a contorted shape that permits it to fit into the limited available space on the substrate, while having an electrical length that is greater than a maximum length dimension of the substrate. Possible shapes for the antenna may include a meander antenna, a non-uniform meander antenna, a bent dipole antenna, a spiral antenna, a z-shaped dipole, a squeezed dipole antenna, or a combination of any of the antenna types. The RF transponder may further include at least one loading bar spaced from the antenna and/or at least one tuning stub coupled to the antenna.
-
Citations
21 Claims
-
1. An RF transponder including a front end, signal processor, and a memory, said transponder comprising:
-
a substrate;
an RF integrated circuit disposed on said substrate;
an antenna provided on said substrate and coupled to said RF integrated circuit, said antenna having an electrical length that is greater than a maximum length dimension of said substrate and having an input impedance including a real component and a reactive component;
at least one loading bar spaced from said antenna, wherein at least one of a bar length, bar width, spacing and number of bars of said at least one loading bar is selectively adjusted to reduce said real component of said input impedance of said antenna such that sufficient voltage is transmitted to said front end to operate said front end and said signal processor of said transponder; and
at least one tuning stub coupled to said antenna, wherein at least one of a stub length, stub conductor width, and stub conductor spacing is selectively adjusted to change said reactive component of said input impedance of said antenna such that said reactive component of said antenna substantially equals a negative magnitude of a reactive part of an input impedance of said front end. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A method for fabricating an RF transponder on a small form factor substrate, said transponder including a front end, signal processor, and memory, said method comprising:
-
disposing an RF integrated circuit on said substrate;
forming an antenna on said substrate in electrical connection with said RF integrated circuit, said antenna having an electrical length that is greater than a maximum length dimension of said substrate and having an input impedance including a real component and a reactive component;
forming at least one loading bar spaced from said antenna such that sufficient voltage is transmitted to said front end to operate said front end and said signal processor of said transponder; and
forming at least one tuning stub coupled to said antenna such that said reactive component of said input impedance of said antenna substantially equals a negative magnitude of a reactive part of an input impedance of said front end. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
-
Specification