Abstract

A frequency-diverse metasurface antenna with hybrid bunching methods for coincidence imaging is proposed in this paper. The hybrid frequency-diverse bunching metasurface antenna contains an excitation system, a frequency-diverse metasurface and a double-layer-metal-plate bunching system. Firstly, the excitation system of the metasurface antenna is divided into two parts, the bunching-excitation module and the random-excitation module. The bunching-excitation module includes a seven-element coherent antenna array that can generate bunching beams with 80 degree beamwidth from 32GHz to 36GHz; and the random-excitation module includes eight antenna elements distributed evenly to excite the frequency-diverse metasurface in the same working bandwidth. A multilayer feed system is also designed utilizing the stripline structure to feed both the bunching-excitation module and the random-excitation module. Secondly, six kinds of metamaterial elements possessing disparate transmitted phases are selected to constitute the frequency-diverse metasurface. The frequency-diverse metasurface is loaded to the excitation system to generate the frequency-diverse radiation patterns. Then, in order to achieve a narrower bunching angle, a double-layer-metal-plate bunching system is designed. Furthermore, the performances of the proposed bunching metasurface antenna, including the radiation efficiency, the reflection coefficient and the correlation coefficients of radiation patterns at different frequencies are evaluated. Finally, the coincidence imaging experiment is carried out using the proposed hybrid bunching metasurface antenna and the image of the target is reconstructed successfully. The designed is verified by both simulations and measurements.

Highlights

  • High accuracy and fast imaging system of microwave and millimeter wave has been widely used in security check, precision guidance and medical imaging

  • When excited by the random excitation module (REM), the metasurface can generate random radiation patterns that are superposed onto the bunching beam as shown in Fig. 6(b), which is suitable to be used as measurement modes in coincidence imaging

  • The radiation patterns of the hybrid frequency-diverse bunching metasurface antenna (HFDBMA) are designed to serve as measurement modes in coincidence imaging, which requires that different measurement modes should be low-correlated [33], [34]

Read more

Summary

INTRODUCTION

High accuracy and fast imaging system of microwave and millimeter wave has been widely used in security check, precision guidance and medical imaging. The frequencydiverse metasurface antenna is a new kind of metamaterial based aperture antenna that can generate different radiation patterns at different frequencies. Hunt demonstrated a microwave imaging system that combines computational imaging techniques with metamaterial aperture antenna design [14]. Yurduseven proposed a lens-loaded coded aperture that can increase information capacity [27] It is a cavity metasurface antenna with a semi-spherical shaped dielectric lens that can focus the beams on the target and improve the number of effective measurement modes. In order to generate frequency-diverse bunching random (FDBR) radiation patterns, a hybrid method is proposed in this paper.

THE EXCITATION SYSTEM
SIMULATED AND MEASURED RESULTS
THE DLMP BUNCHING SYSTEM
COINCIDENCE IMAGING EXPERIMENT
CONCLUSION
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call