CN-116505281-B - Polarization converter for controlling frequency characteristics by terminating filter circuit

Abstract

The invention discloses a polarization converter for controlling frequency characteristics by utilizing a termination filter circuit, which comprises a dual-polarized antenna array and a filter circuit arranged on the back surface of an antenna array floor, wherein the dual-polarized antenna array is used for transmitting received electromagnetic wave signals to the filter circuit arranged on the back surface of the antenna array floor and transmitting signals passing through the output end of the filter circuit to a free space, and the filter circuit is used for controlling the frequency characteristics of the polarization converter. By arranging different filter circuits on the back of the antenna array floor, polarization converters with different frequency characteristics can be obtained. The invention designs a reflective polarization converter with ultra-wideband and dual-band. When electromagnetic waves of linear x-polarization or y-polarization are irradiated to the polarization converter surface, the reflected waves are orthogonally polarized. The invention can be used for antenna design, radar Cross Section (RCS) reduction and wireless communication technology.

Inventors

• WU WEN
• WANG BING
• ZONG ZHIYUAN
• FANG DAGANG

Assignees

• 南京理工大学

Dates

Publication Date

20260512

Application Date

20220119

Claims (6)

1. 1. The polarization converter is characterized by comprising a dual-polarized antenna array and a filter circuit arranged on the back surface of the floor of the dual-polarized antenna array; The dual polarized antenna array is used for receiving the linear polarized incident wave of x-polarization or y-polarization and converting the linear polarized incident wave into y-polarization or x-polarization; The filter circuit is used for controlling the filter characteristic of all-pass/band-pass and realizing the frequency response of ultra-wideband/dual-band; The dual-polarized antenna array comprises a plurality of antenna units, wherein the antenna units comprise a wide-angle matching layer (1), a metal oscillator medium plate (2), a supporting layer (3) and a shared floor (9) which are sequentially arranged from top to bottom, a horizontal metal oscillator radiating plate (5) and a vertical metal oscillator radiating plate (6) which are positioned on the same horizontal plane are arranged between the wide-angle matching layer (1) and the metal oscillator medium plate (2), a coupling metal wafer (7) is arranged between the metal oscillator medium plate (2) and the supporting layer (3), the coupling metal wafer (7) is connected to the shared floor (9) through a vertical through hole (8), the horizontal metal oscillator radiating plate (5) and the vertical metal oscillator radiating plate (6) are respectively connected to the shared floor (9) through two vertical short-circuit through holes (10, 11), the horizontal metal oscillator radiating plate (5) penetrates through the shared floor (9) through a first vertical signal through hole (12), and the output end of the filter circuit is connected with the vertical metal oscillator radiating plate (6) through a second vertical signal through hole (16); The metal oscillator dielectric plate (2) and the supporting layer (3) are of asymmetric crisscross structures; The horizontal metal oscillator radiation sheet (5) and the vertical metal oscillator radiation sheet (6) are respectively positioned on two arms of the crisscross structure of the metal oscillator medium plate (2), so that an asymmetric crisscross structure is formed; the coupling metal disc (7) is arranged at the crossing position of the crisscross structure.
2. 2. The polarization converter using the termination filter circuit to control frequency characteristics according to claim 1, wherein the horizontal metal oscillator radiation sheet (5) and the vertical metal oscillator radiation sheet (6) respectively include two oscillator arms, one of which is a feed terminal and the other of which is grounded.
3. 3. The polarization converter using the terminating filter circuit to control frequency characteristics according to claim 1, wherein the center position of the coupling metal disc (7) is connected to the common floor (9) through a vertical through hole (8), the horizontal metal oscillator radiating plate (5) and the ground oscillator arm of the vertical metal oscillator radiating plate (6) are connected to the common floor (9) through vertical short-circuit through holes (10, 11), respectively, the feed end of the horizontal metal oscillator radiating plate (5) penetrates through the common floor (9) through a first vertical signal through hole (12) to be connected to the input end of the filter circuit, and the output end of the filter circuit is connected to the feed end of the vertical metal oscillator radiating plate (6) through a second vertical signal through hole (16).
4. 4. The polarization converter of claim 1, wherein the filter circuit comprises an all-pass filter or a band reject filter to achieve ultra-wideband/dual-band frequency response, respectively.
5. 5. The polarization converter using a termination filter circuit to control frequency characteristics according to claim 4, wherein the band reject filter includes an input microstrip line (14), a first microstrip line (17), a second microstrip line (18), a third microstrip line (19), and an output microstrip line (15) connected in this order on a main transmission line, and a fourth microstrip line (20), a fifth microstrip line (21), and a sixth microstrip line (22) located at three branch lines of a front end, a middle, and an end of the second microstrip line (18), respectively.
6. 6. The polarization converter of claim 4 wherein the all-pass filter is a 50 ohm microstrip line.

Description

Polarization converter for controlling frequency characteristics by terminating filter circuit Technical Field The invention belongs to the field of polarization converters, and particularly relates to a polarization converter for controlling frequency characteristics by using a termination filter circuit. Background Polarization is an important property of electromagnetic waves. The use of polarization converters is required when the polarization of the incident electromagnetic wave differs from the desired polarization. Polarization converters have important applications in antenna design and RCS reduction. Conventional polarization transformer designs typically utilize birefringence effects and gratings, which require long propagation distances to achieve the desired phase change, and thus the polarization transformer designs utilizing this approach are relatively bulky and have a relatively narrow bandwidth. In recent years, with the increasing maturity of the metamaterial/super surface technology, a polarization converter designed by utilizing the metamaterial/super surface technology has application in the microwave band to the optical band. Among them, the reflective linear cross polarization converter using the anisotropic super surface design has many applications. Many scholars have designed ultra-wideband, low profile, high efficiency polarization converters using anisotropic subsurface. And by reasonably designing the unit structure of the anisotropic super surface, such as a double-square open resonant ring structure, a double-C-shaped narrow ring structure, a double-notch slotted metal ring structure and the like, the dual-band and high-efficiency polarization converter can be designed. However, the use of anisotropic subsurface design requires a comprehensive consideration of polarization conversion characteristics and frequency characteristics, which requires careful design of cell patterns in designing ultra-wideband or multi-band polarization converters to meet both polarization and frequency requirements, which poses a difficulty in design. Also, when the desired frequency characteristics are changed, the entire unit structure needs to be redesigned. Meanwhile, the polarization conversion performance of the polarization converter designed by utilizing the anisotropic super-surface is easy to change under the irradiation of oblique incident waves with large angles, so that the polarization converter can not meet the occasion of large-angle irradiation in use. Disclosure of Invention The invention aims to provide a polarization converter which utilizes a filter circuit to control frequency characteristics. The scheme designs the polarization characteristics separately from the frequency characteristics so that the frequency characteristics can be controlled individually. The polarization converter designed by the scheme has good oblique incidence angle characteristics. This solution can be a good complement to the polarization converter design. The technical proposal for realizing the purpose of the invention is that the polarization converter which utilizes the termination filter circuit to control the frequency characteristic comprises a dual polarized antenna array and a filter circuit arranged on the back of the floor of the dual polarized antenna array; The dual polarized antenna array is used for receiving the linear polarized incident wave of x-polarization or y-polarization and converting the linear polarized incident wave into y-polarization or x-polarization; the filter circuit is used for controlling the filter characteristic of all-pass/band-pass and realizing the frequency response of ultra-wideband/dual-band. The dual-polarized antenna array comprises a plurality of antenna units, wherein each antenna unit comprises a wide-angle matching layer, a metal oscillator medium plate, a supporting layer and a common floor which are sequentially arranged from top to bottom, a horizontal metal oscillator radiation sheet and a vertical metal oscillator radiation sheet which are positioned on the same horizontal plane are arranged between the wide-angle matching layer and the metal oscillator medium plate, a coupling metal wafer is arranged between the metal oscillator medium plate and the supporting layer, the coupling metal wafer is connected to the common floor through a vertical through hole, the horizontal metal oscillator radiation sheet and the vertical metal oscillator radiation sheet are respectively connected to the common floor through two vertical short-circuit through holes, the horizontal metal oscillator radiation sheet penetrates through the common floor through a first vertical signal through hole to be connected with the input end of a filter circuit, and the output end of the filter circuit is connected with the vertical metal oscillator radiation sheet through a second vertical signal through hole. Further, the metal oscillator dielectric plate and the supporting layer