Huygens' Metalens-Based Frequency-Diverse Bunching Metacavity Antenna

The performance of computational microwave imaging (CMI) can be limited by the low signal-to-noise ratio (SNR) of the detected signal, which stems from the restricted directivity of the transmitter. To address this challenge, this paper introduces a new solution: a Huygens' metalens (HM)-based frequency-diverse bunching metacavity antenna (FDBMA). By employing a frequency-diverse metacavity, it becomes feasible to generate low-correlated radiation patterns through a simple frequency sweep. These patterns can then serve as the measurement modes within the framework of CMI. To enhance the directivity of the radiation patterns, a two-dimensional (2D) HM is designed to fulfill the necessary transmission phase compensation requirements. The proposed HM-based FDBMA is realized by positioning the metacavity antenna at the focal point of the designed 2D HM. The performance of the proposed HM-based FDBMA is evaluated, including the reflection coefficient, correlation coefficients and singular values of the measurement modes. The proposed design is validated through full-wave simulations.