Broadband circular polarization capsule antenna combining plane and flexible medium

Abstract

The invention discloses a broadband circular polarization capsule antenna combining a plane and a flexible medium and is a capsule antenna which is applied to the internal of the human body and has a broadband circular polarization characteristic and is arranged inside an endoscope. The broadband circular polarization capsule antenna firstly adopts a single-layer circular Rogers medium substrate which has a diameter the same as that of a capsule and coaxial feeding is performed from a bottom; two metal bands are perpendicular to each other on the upper surface of the substrate, wherein one of the metal bands is connected to the ground through short circuit in a position close to the end of a capsule wall and a non-balance feeding mode is formed with the coaxial feeding; on the basis of that, two metal bands on the upper surface of the substrate extend L-shaped branches to the capsule wall so as to achieve following effects: an antenna radiation caliber of the antenna is enlarged and radiation efficiency is increased. Furthermore, the broadband circular polarization capsule antenna of the invention does not occupy too much space inside the capsule while increasing current paths, can better realize miniaturization, forms two orthogonal modes in a needed frequency band and lays the groundwork for circular polarization performance.

Description

technical field [0001] The invention relates to an implanted antenna for wireless communication inside and outside the human body, in particular to a broadband circularly polarized capsule antenna combined with a plane and a flexible medium. Background technique [0002] The wireless capsule endoscope system is one of the representative devices in the personal health diagnosis and treatment system, which allows clinicians to directly observe the images in the human digestive tract. , has shown important research significance and application value in the field of diagnosis and treatment of digestive tract diseases. Among them, due to the invisibility of the position and direction of the implanted capsule antenna, if two linearly polarized antennas are used to transmit signals from the body to the body, it is easy to cause polarization mismatch loss, while the circularly polarized antenna can receive any polarized signal. The incoming wave can be polarized, and its radiated w...

AI Technical Summary

Problems solved by technology

But if only the external antenna has circular polarization performance, 3dB loss is unavoidable

[0003] It is very difficult to study circularly polarized implanted antennas. The differences in the human body and various parts of the human body, as small as changes in the implantation depth, will have an impact on its performance. So far, there have been few studies on circularly polarized implanted antennas.

In 2009, the team led by Y.Rahmat-Samii proposed the dipole capsule antenna. The antenna is designed on the capsule wall to reduce the antenna volume. It has certain circular polarization performance, but the axial ratio performance still needs to be improved.

In the same year, C. R. Liu proposed an implanted antenna in the form of a rising helix, which obtained a wider axial ratio bandwidth, but its multi-layer structure occupied more space

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