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CN-122026113-A - Leakage waveguide system with planar uniform radiation and design method thereof

CN122026113ACN 122026113 ACN122026113 ACN 122026113ACN-122026113-A

Abstract

The invention relates to the field of leaky waveguides, in particular to a leaky waveguide system with planar uniform radiation and a design method thereof, which have simpler structure and easy manufacture, can ensure good impedance matching and provide a radiation field with high radiation efficiency and high surface uniformity. The leakage waveguide system comprises a leakage waveguide, radiation slits and matching slits, the leakage waveguide system is erected along the transmission direction according to requirements, the radiation slits and the matching slits are rectangular long grooves and are arranged on the surface of the leakage waveguide and are periodically staggered along the propagation direction of the waveguide, the radiation slits are arranged in close proximity along the central line of the wide side of the tube body of the leakage waveguide, and the matching slits are arranged on the other half-width surface opposite to the radiation slits. The invention is suitable for the design of the leakage waveguide.

Inventors

  • DENG XIONG
  • ZHOU XIANGXUE
  • ZOU XIHUA
  • PAN WEI
  • YAN LIANSHAN

Assignees

  • 西南交通大学

Dates

Publication Date
20260512
Application Date
20260209

Claims (8)

  1. 1. The utility model provides a leakage waveguide system of plane uniform radiation, its characterized in that, including leakage waveguide (4), radiation gap (2), matching gap (1), the leakage waveguide system erects along transmission direction as required, radiation gap (2) and matching gap (1) are the elongated slot of rectangle, set up on the surface of leakage waveguide (4) to along the periodic staggered arrangement of waveguide propagation direction, the central line (3) next-door neighbour setting of body broadside of leakage waveguide (4) is followed in radiation gap (2), matching gap (1) set up on the opposite half-width face with radiation gap (2).
  2. 2. Leaky waveguide system with planar uniform radiation according to claim 1, characterized in that the impedance of the matching slot (1) is inverse to the impedance characteristic of the radiating slot (2) and is compensated for to achieve impedance matching.
  3. 3. Leaky waveguide system for planar uniform radiation according to claim 1, characterized in that the arrangement position of the matching slits (1) in the propagation direction corresponds to the arrangement position of the radiation slits (2).
  4. 4. Leaky waveguide system with planar uniform radiation according to claim 1, characterized in that the radiating slot (2) is dimensioned such that it is in resonance in the center frequency range of a preset operating frequency band.
  5. 5. Leaky waveguide system for planar uniform radiation according to claim 1, characterized in that the radiation slots (2) are dimensioned and arranged periodically for excitation generating-1 st order spatial harmonics.
  6. 6. The planar homogeneously radiating leaky waveguide system according to claim 1, wherein the body of said leaky waveguide (4) is configured to operate in a single mode transmission state within a predetermined operating frequency band.
  7. 7. A method of designing a planar uniform radiation leaky waveguide system as claimed in any one of claims 1-6, comprising: s1, determining basic structure parameters; Based on the target center operating frequency f 0 and the desired radiation direction Selecting corresponding standard rectangular waveguide to ensure stable TE10 single-mode transmission in target frequency band and radiation direction The relationship to the structural parameters is determined by the following formula: ; Wherein, the Indicating the angle between the radiation direction and the axis of the waveguide, Representing the central operating frequency The corresponding wavelength of the free space is used, Representing the broadside dimension of the selected waveguide, p representing the arrangement period of the radiation slots; s2, determining the length of a radiation gap to optimize radiation efficiency; According to antenna theory, the initial estimated value of the resonant length of the radiation slot is half of the free space wavelength In the setting range of (2), the final accurate value is found by electromagnetic simulation of a single period unit model to enable the radiation efficiency curve to be at the center frequency The length value at which the peak value is reached; s3, adjusting the width of the radiation gap to accurately control the radiation intensity of the leakage waveguide; by incorporating a plurality of slit units into a segment and having a set length Electromagnetic simulation is carried out on the waveguide model of the device; obtaining the transmission coefficient of the corresponding segment waveguide through simulation And calculate the damping constant according to the following formula : ; By adjusting the width of the radiation slit in the simulation, the radiation slit is calculated The value accords with a preset design target; and S4, designing a matching gap by adopting an equivalent circuit method and combining a PSO algorithm on the premise that the length, the width and the period of the radiation gap are determined.
  8. 8. The method for designing a leaky waveguide system for plane uniform radiation as claimed in claim 7, wherein step S4 includes: initializing the setting: first, the width of the matching gap is preliminarily set , , Representing the radiation slit width, setting the length lo1 and the offset d of the matching slit as optimization variables, namely particle position vectors X= (lo 1, d) in a PSO algorithm, and setting the search space range of the variables according to waveguide size limitation; constructing an equivalent circuit model and an objective function: Constructing an equivalent circuit model, and equating each p/2 length unit in the leakage waveguide to a radiation gap admittance And matching gap admittance A two-port circuit model connected in parallel on a transmission line, wherein And Indicating the conductance, representing the radiation loss, And A representation susceptance representing stored energy; establishing a periodic unit simulation model with the length of p/2 comprising a pair of radiation slits and a matching slit, carrying out joint simulation by using electromagnetic simulation software and an algorithm, extracting S parameters in each iteration, and calculating the total normalized parallel admittance according to the following formula: ; Wherein, the , ; The fitness function of the PSO algorithm is defined as the absolute value of the imaginary part of the total susceptance at the center frequency point f 0 : ; algorithm iteration and optimizing: Initializing a group of particles, wherein each particle represents a group of random (lo 1, d) combinations, in each iteration, firstly, calculating the fitness value of each particle in the current group in a simulation way, updating the individual historical optimal position and the global historical optimal position, and then, according to the speed and the position of the updated particle, finally judging whether the termination condition is met; The way to update the speed and position of the particles is as follows: ; ; wherein V and X represent the current speed and position, respectively, As the weight of the inertia is given, And Respectively is And The weight of the study is set to be the weight of the study, Represents the historical optimal position of the object, And representing a global history optimal position, wherein r1 and r2 are random numbers distributed among [0,1 ].

Description

Leakage waveguide system with planar uniform radiation and design method thereof Technical Field The invention relates to the field of leaky waveguides, in particular to a leaky waveguide system with planar uniform radiation and a design method thereof. Background In many communications and sensing applications leaky waveguide antennas are a key technology because of their ability to form a continuous and directional electromagnetic field distribution along a predetermined path. By periodically opening slots in its waveguide wall, guided wave energy can be accurately converted into radiated waves. The direction of the radiation beam can be flexibly controlled by adjusting the arrangement period of the gaps so as to adapt to the coverage requirements under different scenes. In particular, when the slot cycle is set to excite the-1 st order spatial harmonic to generate broadside radiation, the structure is capable of providing stable signal coverage for a target moving along its path, and is of great value in the field of mobile communications and the like. However, the slit structure with periodic waveguide wavelength can cause serious stopband effect when the continuity of the surface current is damaged on the waveguide, so that obvious impedance mismatch is introduced, especially when the scene of broadside radiation is needed, electromagnetic waves reflected by each slit unit can be overlapped with strong reflection, thereby generating a stopband on a transmission curve, so that energy cannot be effectively transmitted and radiated in a target frequency band, and the transmission efficiency of the waveguide is affected. To solve the above problem, in the prior art, as proposed in CN113161753a, an inductive metal pillar is disposed inside the waveguide wall opposite the radiation slot. The scheme utilizes the mutual compensation of the capacitive effect presented by the longitudinal radiation gap and the inductive effect presented by the metal column, thereby realizing good impedance matching. However, the prior art solutions described above have various disadvantages. First, the manner of matching with internal metal posts is complex in the manufacturing process. This requires precise positioning, mounting and fixing of the plurality of metal posts within the enclosed waveguide body, and requires high precision in machining and assembly, not only increasing production processes, but also increasing manufacturing costs and difficulty. More importantly, the scheme has an unresolved technical defect in electrical performance. In particular, in order to obtain a stronger radiation, its longitudinal radiation slit is usually arranged at a position remote from the centre line of the broadside of the waveguide. This asymmetric arrangement results in a leaky waveguide with a poor uniformity of the distribution of the radiated field strength in the receiving plane below it. For any application scenario depending on uniform field intensity distribution, such a "dead zone" or severe fluctuation of field intensity may cause serious degradation of system performance, resulting in problems such as communication interruption or low energy transmission efficiency. Therefore, there is a need for a leaky waveguide that is simple in structure, easy to manufacture, and provides a radiation field with high radiation efficiency and high surface uniformity. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a leaky waveguide system with planar uniform radiation and a design method thereof, which have simpler structure and easy manufacture, and can ensure good impedance matching and provide a radiation field with high radiation efficiency and high surface uniformity. The present invention adopts the following technical scheme to achieve the above object, and in a first aspect, the present invention provides a leaky waveguide system for planar uniform radiation, including: The novel high-frequency radiation wave guide device comprises a leakage wave guide 4, radiation slits 2 and matching slits 1, wherein the leakage wave guide system is erected along the transmission direction according to requirements, the radiation slits 2 and the matching slits 1 are rectangular long grooves and are arranged on the surface of the leakage wave guide 4 and are periodically staggered along the propagation direction of the wave guide, the radiation slits 2 are arranged next to each other along the central line 3 of the wide side of the pipe body of the leakage wave guide 4, and the matching slits 1 are arranged on the other half-width surface opposite to the radiation slits 2. Further, the impedance of the matching slot 1 is opposite to the impedance characteristic of the radiation slot 2, and is compensated for to achieve impedance matching. Further, the arrangement position of the matching slit 1 along the propagation direction corresponds to the arrangement position of the radiation slit 2. Further,