An Equal-Phase Feeding Method for Discretized Array Arrangement in the Terahertz Band

Abstract

This invention relates to an equal-phase feeding method for a discretized array arrangement in the terahertz band, comprising: determining the coordinates of the cell number and the port number based on the known optimized array arrangement and T / R output port arrangement; determining the correspondence between the cell number and the port number according to the principle of the shortest distance between the cell and the port; determining the distance between all channel cells and ports on the projection plane based on the correspondence between the cell number and the port number; calculating the actual path difference between each channel based on the distance between all channel cells and ports on the projection plane; using the current standard rectangular waveguide in the terahertz band as the feeding transmission segment, determining the physical length of all transmission segments and calculating the average physical length, and taking the channel k closest to the average length as the reference channel. This invention solves the problem of transmission path and feeding phase mismatch between uniformly arranged transmit channels and discretely arranged array cells, and is applicable to different array arrangement and transmit channel arrangement methods.

Description

Technical Field

[0001] This invention relates to an equal-phase feeding method for discretized array arrangement in the terahertz band, belonging to the field of antenna design technology. Background Technology

[0002] Traditional array antenna designs for frequency bands such as X-Ka are based on a uniform arrangement of array elements. The element arrangement and aperture are consistent with the arrangement and aperture of the RF output ports of the T / R components, so the two are directly connected by vertical interlocking. This design is only suitable for array antennas that do not have special requirements for sidelobe level, null depth, and grating lobe position when scanning at large angles.

[0003] The array antenna uses algorithms to optimize the element arrangement based on parameters such as scanning range, gain, grating lobe position, and null depth. The element spacing is typically between 0.5 and 2.5λ, and not all elements are arranged in a uniform layout. There is a serious mismatch between the array antenna element arrangement and the T / R component port arrangement. Summary of the Invention

[0004] The technical problem solved by this invention is: the purpose of this invention is to overcome the above-mentioned shortcomings of the prior art, and to propose an equal-phase feeding method for terahertz frequency band discretized array arrangement, which realizes the equal-phase feeding function of terahertz frequency band discretized array antenna, solves the problem of transmission path and feeding phase mismatch between uniformly arranged transmission channels and discretely arranged array elements, and is applicable to different array surface arrangements and transmission channel arrangements, and has universality.

[0005] The solution of the present invention is:

[0006] A method for equal-phase feeding of a discretized array arrangement in the terahertz band, comprising:

[0007] Based on the known array optimization layout and T / R output port layout, determine the cell number coordinates and port number coordinates;

[0008] Based on the principle of the shortest distance between units and ports, determine the correspondence between unit numbers and port numbers;

[0009] Based on the correspondence between the unit number and the port number, determine the distances between all channel units and ports on the projection plane;

[0010] Calculate the actual path difference between each channel based on the distance between all channel units and ports on the projection plane;

[0011] The current standard rectangular waveguide in the terahertz band is used as the feed transmission section. The physical length of all transmission sections is determined and the average physical length is calculated. The channel k closest to the average length is taken as the reference channel.

[0012] Calculate the electrical length of each channel in the power supply transmission section. Using channel k as a reference, adjust the aperture of the transmission waveguide to make the electrical length of each channel consistent with the electrical length of the reference channel.

[0013] Add conversion waveguides to the input ports and output ports of each channel in the power supply transmission section, and fine-tune the waveguide aperture of the transmission section so that the simulated phase difference between the input and output ports of other channels does not exceed ±1°.

[0014] By adding a feed transmission section between the component output and the array input, and adjusting the waveguide size according to different physical paths, the same electrical length can be achieved for each channel, ultimately achieving equal-phase feeding of array elements with discrete array surfaces.

[0015] Furthermore, based on the optimized cell arrangement of the N-element array and the arrangement of the T / R output ports, the cells and ports are numbered from 1 to N, and projected onto the XOY plane to obtain the cell number coordinates and port number coordinates:

[0016]

[0017] Furthermore, based on the correspondence between units and ports, channel numbers 1 to N are determined using the unit number as a reference.

[0018] Furthermore, the distance `channel_dis_projection` between all channel elements and ports on the projection plane is calculated.

[0019]

[0020] Furthermore, the maximum and minimum values ​​in channel_dis_projection are extracted, the initial value of the transmission module height dh is set, the actual path difference channel_dis between each channel is calculated, and dh is adjusted according to the fact that the difference between max(channel_dis) and min(channel_dis) is no greater than one wavelength, so that there is no over-period phenomenon in the unit feed phase.

[0021] Furthermore, channel_dis = (channel_dis_projection) 2 +dh 2 ) 1 / 2 .

[0022] Furthermore, the average value aver_channel_dis in channel_dis is taken, and the corresponding channel k is used as the reference for all channels to achieve the same transmission path. The current standard rectangular waveguide size of the terahertz band is used to connect the unit and the TR port coordinates as the signal transmission segment of the feed module. The input port of the transmission segment is matched with the TR output port using a conversion waveguide, and the output port of the transmission segment is matched with the unit input port using a conversion waveguide.

[0023] Furthermore, using channel k as a reference, the electrical length of the equal-phase transmission segment is calculated; the waveguide aperture of the transmission segments of channels 1 to N is adjusted so that the electrical length of each channel transmission segment is consistent with the electrical length of the reference channel.

[0024] Furthermore, for a rectangular waveguide operating in the dominant mode TE10, its cutoff frequency...

[0025]

[0026] Cutoff wavelength

[0027] The speed at which the phase surface of the guided mode moves:

[0028]

[0029] In the formula, c and λ0 are the speed of light and wavelength in free space, respectively;

[0030] a is the width of the transmission waveguide, μ is the permeability of free space, ε is the free space permittivity, ω is the angular frequency, β is the phase shift constant, and k is the transmission constant.

[0031] Furthermore, the distance between adjacent in-phase planes of a guided mode in a guiding system, or the distance between phase planes with a phase difference of 2π, is called the waveguide wavelength of that guided mode, denoted by λ. g express:

[0032]

[0033] In the formula This is the cutoff wavelength of the TE10 master mode. The advantages of this invention compared to existing technologies are:

[0034] (1) Based on the relative projection relationship between the TR port and the discrete array unit, the present invention determines the mapping relationship between the port and the unit, so as to minimize the difference in physical transmission paths between different channels;

[0035] (2) This invention achieves the same electrical transmission path by changing the aperture of the waveguide in the transmission section, so that the signal can pass through different physical transmission paths in each channel.

[0036] (3) The present invention matches the waveguide conversion section with the TR output port and the array unit inlet, so that the two ends of the waveguide of different sizes have the same excitation port. Through simulation, the transmission phase of each channel at both ends of the "black box" can be kept consistent. Attached Figure Description

[0037] Figure 1 This is a flowchart of the method of the present invention;

[0038] Figure 2 A diagram showing the structure of a single transmission channel;

[0039] Figure 3 This is a diagram of the overall structure of the transmission module. Detailed Implementation

[0040] The present invention will be further described below with reference to the embodiments.

[0041] A flowchart of an equal-phase feeding method for discretized array arrangement in the terahertz band, as follows: Figure 1 As shown, the specific steps are as follows:

[0042] Step 1: Based on the optimized cell layout and T / R output port layout of the N-element array, number the cells and ports from 1 to N, and project them onto the XOY plane to obtain the cell number coordinates and port number coordinates:

[0043]

[0044] Step 2: Determine the one-to-one correspondence between unit numbers and port numbers based on the principle of the shortest distance between units and ports.

[0045] Step 3: Based on the correspondence between units and ports, determine the channel numbers 1 to N using the unit number as a reference. Calculate the distance `channel_dis_projection` between all channel units and ports on the projection plane.

[0046]

[0047] Step 4: Extract the maximum and minimum values ​​in channel_dis_projection, set the initial value of transmission module height dh, calculate the actual path difference channel_dis between each channel, and adjust dh according to the fact that the difference between max(channel_dis) and min(channel_dis) is no greater than one wavelength, so that there is no over-period phenomenon in the unit feed phase.

[0048] channel_dis=(channel_dis_projection 2 +dh 2 )1 / 2

[0049] Step 5: Take the average value aver_channel_dis from channel_dis, and use the corresponding channel k as the reference for all channels' equal transmission paths. Use the standard rectangular waveguide dimensions of the current terahertz band to connect the unit and TR port coordinates, which will serve as the signal transmission segment of the feed module. The input port of the transmission segment is matched with the TR output port using a conversion waveguide, and the output port of the transmission segment is matched with the unit input port using a conversion waveguide.

[0050] Step 6: Using channel k as a reference, calculate the electrical length of the equiphase transmission segment. Based on transmission line theory and guided wave theory, adjust the waveguide aperture of the transmission segments of channels 1 to N to ensure that the electrical length of each channel transmission segment is consistent with the electrical length of the reference channel.

[0051] For a rectangular waveguide operating in dominant mode TE10, its cutoff frequency and cutoff wavelength are:

[0052]

[0053]

[0054] The speed at which the phase surface of the guided mode moves:

[0055]

[0056] In the formula, c and λ0 are the speed of light and wavelength in free space, respectively. The distance between adjacent in-phase planes of a guided mode in a guiding system, or the distance between phase planes with a phase difference of 2π, is called the waveguide wavelength of that guided mode, denoted by λ. g express:

[0057]

[0058] Step 7: Add a conversion waveguide to the input port and output port of the equal-phase transmission section, respectively, and match them with the TR output port and unit inlet. Set the height to one wavelength and substitute it into HFSS for simulation. At this time, the input and output port diameters of the entire equal-phase transmission module are consistent. Taking the k-channel as the reference, add a 0.05mm chamfer to the conversion section and the transmission section. The simulated phase difference between its input and output ports is deg_k. Figure 2 As shown. The waveguide aperture of the transmission section is finely adjusted so that the simulated phase difference between the input and output ports of all other channels is deg_k, with an error not exceeding ±1°, thus obtaining the apertures a1 to a2 of all transmission channels. N ,like Figure 3 As shown.

[0059] This invention innovatively proposes an equal-phase feeding method for terahertz frequency band discretized array antennas. This method can solve the problem of unequal path signal transmission between regularly distributed RF output ports and irregularly discrete array elements. The mapping relationship between elements and ports is determined based on their relative projection. Then, based on transmission line theory and guided wave theory, the waveguide aperture of the transmission section is changed to initially optimize the phase inconsistency between channels. Furthermore, by adding a waveguide conversion section, the input and output states of each channel are unified, and simulation ensures the consistency of the transmission phase at both ends of each channel in the "black box". The transmission module designed using this method has a simple structure and high precision, providing a simple and quick feeding method for terahertz frequency band discretized array antennas.

[0060] This invention discloses an equal-phase feeding method for a discrete array arrangement in the terahertz band. First, based on the discrete array arrangement and the port spacing of the transmit channel after optimization of the array antenna performance, the correspondence between the array elements and the channel output ports is determined. The height of the transmission module is reasonably set to ensure that the transmission path difference of each element is less than one wavelength, thus preventing the element feeding phase from being over-period.

[0061] This invention optimizes the waveguide aperture in the transmission module by considering the relationship between the signal wavelength and the aperture of the waveguide, ensuring that the signal arrives at each element with equal phase. This enables beamforming and coverage in the spatial domain through the antenna. Using this method, the problem of unequal path signal transmission between regularly distributed RF output ports and irregularly discrete array elements can be solved. The transmission channel structure designed by this invention is simple, highly accurate, and easily implementable, providing a simple and quick feeding method for discrete array antennas in the terahertz band.

[0062] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for feeding an equal phase of a terahertz band discretization array arrangement, characterized in that, Comprise: According to the known array optimization arrangement and T / R output port arrangement, determine the unit number coordinates and port number coordinates; According to the principle of the closest distance between the unit and the port, determine the corresponding relationship between the unit number and the port number; According to the corresponding relationship between the unit number and the port number, determine the distance channel_dis_projection of all channel units and ports on the projection plane; channel_dis_projection = ((ele_x_pos - TR_x_pos) 2 + (ele_y_pos - TR_y_pos) 2 ) 1 / 2 Based on the distance of all channel units and ports on the projection surface, the actual path difference between each channel is calculated; the specific way is: the maximum value and the minimum value in channel_dis_projection are extracted, the initial value dh of the transmission module height is set, the actual path difference channel_dis between each channel is calculated, according to the difference between max(channel_dis) and min(channel_dis) is not greater than one wavelength, dh is adjusted, so that the unit feeding phase does not exist super cycle phenomenon; channel_dis=(channel_dis_projection 2 +dh 2 ) 1 / 2 ; Using the current terahertz frequency band standard rectangular waveguide as the feed transmission section, determine the physical length of all transmission sections and calculate the average physical length, and take the channel k closest to the average length as the reference channel; Calculate the electrical length of each channel of the feed transmission section, take channel k as the reference, adjust the transmission waveguide aperture, and make the electrical length of each channel consistent with the electrical length of the reference channel; Increase the conversion waveguide at the input port of each channel of the feed transmission section, and increase the conversion waveguide at the output port, fine-tune the transmission waveguide aperture, so that the simulated phase difference between the input and output ports of each channel does not exceed ±1°; By increasing the feed transmission section between the component output and the array input, adjust the waveguide size according to different physical paths, so that each channel realizes the same electrical length, and finally realizes the equal phase feeding of the array elements of the array dispersion.

2. The method of claim 1, wherein, According to the unit arrangement and T / R output port arrangement of the N-element array optimization, number the units and ports 1-N, and project them on the XOY plane to obtain the unit number coordinates and port number coordinates:

3. The method of claim 2, wherein, According to the corresponding relationship between the unit and the port, take the unit number as the reference to determine the channel number 1-N.

4. The method of claim 1, wherein, Take the average value aver_channel_dis in channel_dis, corresponding to channel k as the reference of all channel equal transmission paths, use the current terahertz frequency band standard rectangular waveguide size to connect the unit and TR port coordinates, as the signal transmission section of the feed module; The input port of the transmission section uses a conversion waveguide to match the TR output port, and the output end of the transmission section uses a conversion waveguide to match the unit input port.

5. The method of claim 1, wherein, Take channel k as the reference to calculate the electrical length of the equal phase transmission section; Adjust the waveguide aperture of 1-N channel transmission section, so that the electrical length of each channel transmission section is consistent with the electrical length of the reference channel.

6. The method of claim 5, wherein, For a rectangular waveguide operating in the dominant TE10 mode, the cutoff frequency cutoff wavelength The speed of the guided mode equal phase plane movement: wherein c and λ0are the speed of light in free space and the wavelength, respectively; a is the width dimension of the transmission waveguide, μ is the magnetic permeability of free space, ε is the dielectric constant of free space, ω is the angular frequency, β is the phase shift constant, and k is the transmission constant.

7. The method of claim 6, wherein, The distance between adjacent in-phase planes of a guided mode in a waveguide system, or the distance between planes of phase difference 2π of the guided mode, is called the waveguide wavelength of the guided mode, denoted by λ g . In the formula is the cutoff wavelength of the TE10 main mode.

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