Double-loop antenna applied to 4G-MIMO intelligent glasses

Abstract

The invention belongs to the technical field of a wearable antenna and particularly relates to a double-loop antenna applied to 4G-MIMO intelligent glasses. The antenna is characterized in that the shape of the glasses is fully utilized, the loop antenna is printed on a glasses frame, and an MIMO antenna structure is formed according to the symmetry performance of the glasses; coverage of frequency bands of GSM850 / 900, GSM1800 / 1900, UMTS2100, LTE2300 / 2500 and the like is realized by loading a matching circuit; furthermore, by loading a decoupled parasitic element, near-field coupling between two antennas is effectively reduced, so minimum isolation of two antennas at a low frequency band also reaches -15dB or below; moreover, introduction of the decoupling parasitic element has little influence on self-impedance of the antenna, and the bandwidth can still cover two frequency bands of 824-960 MHz and 1710-2690 MHz of 4G, and thereby the double-loop antenna not only conforms to the application of the intelligent glasses, but also meets the decoupling requirement.

Description

technical field [0001] The invention belongs to the technical field of wearable antennas, and in particular relates to a double-loop antenna applied to 4G-MIMO smart glasses. Background technique [0002] In recent years, multiple-input multiple-output MIMO technology has been proposed, which can effectively improve the performance of wireless communication systems, and use the characteristics of multipath to improve the channel capacity and communication quality of the system; in this technology, the design of the antenna plays an important role. Very important role as it is the communication transport tool between transmitter and receiver. In order to obtain the performance of the MIMO system, the antennas on the transmitter and receiver should be uncorrelated; theoretically speaking, when the distance between the two antennas reaches more than half the wavelength of the antenna, the antennas will not affect each other, but this This is impossible for miniaturized smart d...

AI Technical Summary

Problems solved by technology

External decoupling includes parasitic element decoupling, matching circuit decoupling, floor printing seam decoupling, and neutral line decoupling. These methods are decoupling structures added outside the antenna structure; among them, adding a matching circuit to reduce The antenna bandwidth obtained by the coupling method is narrow. In addition, most matching circuits are similar to filter structures, so multimode decoupling can be achieved by referring to the theory of multimode filters. However, if the number of decoupling modes increases, the design will be difficult. It will become very difficult, because the matrix corresponding to the filter will become very complicated; the floor printing slot decoupling is actually for the antenna elements that share the floor, it is to reduce the gap between the two antenna elements through the slot The flow of the floor current between the ground, thereby reducing the coupling; there is no standard criterion for the design of the neutral line, it is difficult to reduce the broadband mutual coupling

Internal decoupling includes odd and even mode decoupling, mirror antenna element decoupling, eigenmode theoretical decoupling, and multi-polarization decoupling; eigenmodes can achieve good isolation for frequency bands below 1GHz, but it is difficult to control the frequency of multiple eigenmodes , because the flexibility to modify the radiator is very limited; in addition, there are methods for flawlessly decoupling antennas that share a floor, but this structure is too bulky for mobile terminals

[0005] For the dual-loop antenna applied to 4G-MIMO smart glasses, two simple loop antennas achieve frequency band coverage through matching circuits; since the two antennas do not share the floor structure, the defective ground and floor slots are decoupled None of the methods can achieve the reduction of mutual coupling; and, because the glasses have a single form and a fixed structure, the design space required for the matching circuit decoupling scheme is also greatly limited

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