Signal processing circuit, and non-contact IC card and tag with the use thereof
First Claim
1. A signal processing circuit comprising an IC including an RF circuit and a rectangular spiral antenna being a planar coil and communicating by using at least two carrier frequencies.
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Accused Products
Abstract
To provide an RFID (a signal processing circuit) equipped with a single rectangular spiral antenna and being capable of transmitting and receiving an electric power and signal by a plurality of frequency bands therewith, the present invention limits a longitudinal dimension (long sides) of the rectangular spiral antenna designed for transmission and reception of carrier of the HF band thereby to the length suitable for transmission and reception of carrier of the UHF band thereby as well as a widthwise dimension thereof so as to prevent a current waveform due to the carrier of the UHF band from reversing in phase at one of the long sides thereof.
146 Citations
15 Claims
- 1. A signal processing circuit comprising an IC including an RF circuit and a rectangular spiral antenna being a planar coil and communicating by using at least two carrier frequencies.
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8. A signal processing circuit comprising:
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a first circuit element responding to a first signal transmitted by the carrier of a first frequency;
a second circuit element responding to a second signal transmitted by the carrier of a second frequency being higher than the first frequency; and
a rectangular spiral antenna formed on a plane composed of a first and a second side opposing each other and a third and a fourth side opposing each other and being shorter than any of the first and the second side;
whereinthe rectangular spiral antenna is formed by connecting the other end of one of an adjacent pair of N conductor lines running from one end of the first side on the plane to the other end of the first side via the third, the second and the fourth side in that order and not intersecting with each other to one end of the other of the adjacent pair of N conductor lines, and the first and the second circuit elements are connected to the one end of one of the N conductor lines provided at the outermost periphery on the plane. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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Specification