A Miniaturized Circularly Polarized Reader Antenna Capable of Reading Near and Far Fields

Abstract

The invention relates to a miniaturized circularly polarized reader antenna capable of both near and far field reading. Based on the principle of electromagnetic metamaterials and the theory of aperture surface radiation, a metamaterial structure is used as a radiator, and a ring-shaped superresonator configuration is proposed. It solves the shortcomings of the traditional reader antenna, which is large in size or complex in structure, difficult to apply in space-constrained products or miniaturized equipment, and the shortcomings of traditional solutions that are difficult to apply on a large scale due to high cost. The entire antenna structure is simple, low in cost, and the antenna works The bandwidth is wide, and the in-band radiation performance is stable, which can meet the communication requirements of various IoT devices such as RFID in different frequency bands; and the antenna realizes high-gain circularly polarized radiation in the far field, and realizes the aperture surface in the near field. The uniform field distribution enables stable and reliable communication in both the near-field area and the far-field area, and solves the problem and blind spot that traditional reader antennas are difficult to take into account both long-distance and short-distance communication.

Description

technical field [0001] The invention relates to a miniaturized circularly polarized reader antenna which can take both near and far field reading into consideration, and belongs to the technical field of radio frequency antennas. Background technique [0002] At present, with the rapid advancement and continuous development of the Internet of Things, the Internet of Things technology has been deeply integrated into people's lives and production. As an important part of the Internet of Things system, radio frequency identification technology (RFID) is widely used in people's daily life and industry. In production, such as access control card management system, station automatic toll collection system and various industrial automation equipment. RFID technology can be divided into tag antennas and reader antennas in the wireless communication part. Tag antennas are mainly linearly polarized antennas of a type of bent line electric dipoles and magnetic dipoles. Reader antennas ...

AI Technical Summary

Problems solved by technology

The near-field reader antenna will produce a uniform field distribution in the near-field area, and there is basically no radiation in the far-field area due to the mutual cancellation of the fields. The farther space cannot realize read communication

Circularly polarized reader antennas mainly include circularly polarized patch antennas, orthogonal dipole pair antennas, and sequential rotating feed antennas. The field distribution of such antennas in the near-field area is limited and uneven. The area will produce a strong radiation ability to realize long-distance reading communication, but in the short distance, there are often phenomena such as missed reading.

[0004] Among them, the circularly polarized patch antenna scheme, due to the limitation of its radiation mechanism, has a narrow working bandwidth, and the field distribution in the near-field area is mainly composed of two magnetic gaps, which makes it difficult to take into account both near-field and far-field reading.

Orthogonal dipole pair circularly polarized antenna is mainly composed of two dipoles with orthogonal frequency perturbation. This scheme has the problem of high antenna profile, which is difficult to apply in space-constrained industrial equipment

Sequential rotating feed antennas, usually two to four radiating elements, are fed and radiated with an additional phase-shifted feed network. This solution has the disadvantages of complex structure, high cost, and large antenna loss, and it is difficult to implement in large-scale industrial production lines. Promote apps on

Through the review and analysis of the above existing technologies, the current RFID reader antennas are difficult to achieve miniaturization, low cost, and both near and far field reading communication, so the existing reader antennas are difficult to meet the needs of both near and far field communication scenarios

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