Research On Wearable Antenna And On-Chip Antenna Based On Artificial Magnetic Conductor

With the continuous development of electronic information technology and its wide application in all walks of life,the requirements for antennas in application scenarios such as wireless communication,radar detection,and inter-chip communication are constantly increasing,and ordinary conventional antennas are becoming more and more difficult to meet the needs.In recent years,the application of new electromagnetic structures such as artificial magnetic conductors in the field of microwave,millimeter-wave and terahertz antennas has become a research hotspot.In the information transmission in the field of wearable devices,the antenna is one of the key modules.How to make the antenna work stably on the surface of the human body and how to ensure the radiation safety of the antenna to the human body are very important issues;The on-chip antenna has significant advantages such as reducing the size of the on-chip system because it is integrated on the chip.However,how to reduce the negative impact of the silicon-based process on the radiation of the on-chip antenna is a difficult problem to be solved.In this context,this paper mainly studies wearable antennas and millimeter-wave high-frequency on-chip antennas for Wireless Body Area Network.Through theoretical analysis of the reflection phase zero point and bandwidth,different artificial magnetic conductor structures are designed to improve the application performance of the antenna.Committed to solving the problems of loading artificial magnetic conductors in wearable antennas to reduce electromagnetic radiation,and loading artificial magnetic conductors in on-chip antennas to reduce the influence of thicker silicon substrates on antennas.The main research work of this paper is as follows:1.A 5G wearable antenna is designed by comprehensive analysis and research of single-frequency miniaturized artificial magnetic conductor and planar slot antenna.Aiming at the problem that the reflection phase bandwidth of the annular artificial magnetic conductor is too narrow,orthogonal elliptical branches are introduced on the upper surface,and at the same time,the ground is subjected to similar structure reduction and slotting to realize a miniaturized artificial magnetic conductor whose reflection phase bandwidth completely covers the 5G frequency band of China Unicom.It is formed into a 3×4 array and placed under the antenna to test its own performance and wearable performance.The Specific Absorption Rate(SAR)of the antenna 1g standard is greatly reduced,far below the limit of human safety standards.The measured results also meet the requirements of the antenna.2.A dual-band wearable antenna based on artificial magnetic conductors is designed,which consists of dual-band broadband artificial magnetic conductors and a planar monopole antenna with band-notch characteristics.By introducing the branch "X" on the upper surface,the high-frequency reflection phase bandwidth of the original double-ring artificial magnetic conductor structure is increased by 72%,so that it completely covers the ISM(Industrial Scientific Medical)medical frequency range.The dual-frequency antenna realized by the notch technology is combined with the 2×3artificial magnetic conductor structure,and its wearable performance is simulated and tested,such as the performance under the bending shape and the radiation safety of the antenna to the human body.3.A millimeter-wave high-band on-chip antenna based on artificial magnetic conductors is designed.Based on the standard CMOS(Complementary Metal Oxide Semiconductor)process,an hourglass-shaped artificial magnetic conductor with a simple structure was designed,and the effects of electromagnetic parameters and different metal layers on the reflection characteristics of the artificial magnetic conductor were analyzed.After the 4×4 artificial magnetic conductor structure is loaded on the on-chip antenna fed by the GSG probe,a broadband of 60.9 GHz is obtained,and the gain is also greatly improved.Due to the small size of the overall onchip antenna design,it has certain advantages in monolithic Millimeter-Wave chip integration.This paper analyzes the common performance problems of antennas in the two fields of wearable antenna and on-chip antenna.Without introducing additional processing conditions,it is expounded that the in-phase reflection characteristics of the artificial magnetic conductor structure can play an important role in improving the gain of the antenna towards the free space and reducing the coupling between the antenna and the medium seriously affecting the antenna radiation.Finally,suitable artificial magnetic conductor structures were designed in the two antenna fields,and the performance of the loaded antennas was improved well.