Method for expanding lower limit of working frequency band of coplanar Vivaldi antenna

Abstract

The invention belongs to the technical field of electromagnetic fields and microwaves, and particularly relates to a method for expanding the lower limit of a working frequency band of a coplanar Vivaldi antenna. A closed groove similar to a radiation patch in shape is formed in a traditional coplanar Vivaldi antenna metal radiation patch, a curve radiation arm is constructed, two metal radiation patches with gradually changing indexes are equivalently constructed, and current distribution is improved; the first curve radiation arm 12, the first linear radiation arm 13 and the second linear radiation arm 14 form an upper side loop radiation structure, and the second curve radiation arm 22, the third linear radiation arm 23 and the fourth linear radiation arm 24 form a lower side loop radiation structure, so that the effective length of a current propagation path on the surface of the antenna is effectively prolonged, and the low-frequency radiation capability of the antenna is enhanced; and meanwhile, parallel slot lines are arranged on the first linear radiation arm 13 and the third linear radiation arm 23, and resistance loading is carried out, so that impedance matching is facilitated, antenna reflection is reduced, part of low-frequency components are absorbed to the greatest extent, and then the lower limit of the working frequency band of the antenna is further remarkably expanded.

Description

technical field [0001] The invention belongs to the technical field of electromagnetic fields and microwaves, and in particular relates to a method for expanding the lower limit of the operating frequency band of a coplanar Vivaldi antenna. Background technique [0002] The Vivaldi antenna is a planar end-fired gradient slot antenna. Due to its advantages such as wide operating frequency bandwidth, good directivity, high gain, and simple structure and easy processing and integration, it is widely used in ultra-wideband fields, such as radar detection, ultra-wideband communication, etc. . Vivaldi antennas can be roughly divided into two categories, one is coplanar Vivaldi antenna fed by microstrip-slot line coupling, and the other is antipodal Vivaldi antenna fed by microstrip-parallel dual-wire feed. The upper limit of the operating frequency band of the coplanar Vivaldi antenna is limited by its feeding structure, and thus the antipodal Vivaldi antenna has evolved. Howeve...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a method for expanding the lower limit of the operating frequency band of the coplanar Vivaldi antenna to solve the technical problem that the lower limit of the operating frequency band of the Vivaldi antenna is limited by the size of the antenna

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