Meander Line RFID Antenna Impedance Matching

The patent transitions from a conventional planar antenna structure to a three-dimensional folded meander line structure. The antenna conductor is folded back and forth in the vertical direction, creating multiple layers and levels. This dimensional transformation allows the antenna to achieve a longer effective electrical length within a compact footprint, thereby maintaining higher input impedance and better impedance matching with the IC circuit even in reduced-size RFID tags.

The patent employs a nested structure where the meander line antenna is folded into multiple compact layers. Each fold creates a nested configuration that packs more conductor length into a smaller volume. This nesting approach enables the antenna to maintain its electrical performance characteristics while significantly reducing the overall tag size, resolving the contradiction between miniaturization and impedance matching.

By folding the antenna conductor in the vertical dimension rather than extending it horizontally, the patent achieves a longer effective radiating length without increasing the horizontal footprint. The folded meander line structure creates multiple vertical segments that contribute to the overall electrical length, enabling the antenna to maintain communication distance and sensitivity while occupying less surface area.

The patent changes the geometric parameters of the antenna structure by introducing fold angles, segment lengths, and spacing between folded sections. By optimizing these parameters, the antenna achieves improved current distribution and impedance characteristics that maintain communication performance despite reduced surface area. The folded structure allows for better control of current flow patterns, enhancing radi efficiency.