CN103337707A - Double-slot-depth tri-band differential mode tracking feed source and design method thereof - Google Patents

Abstract

The invention discloses a double-slot-depth tri-band differential mode coupling feed source and a design method thereof. A differential mode signal is coupled within a double-slot-depth corrugated groove cycle to achieve a single-band monopulse tracking function. Within three separate bands, such excellent characteristics as a rotational symmetry in a dominant mode radiation direction of a pattern, a low sidelobe level, a low reflection loss and a high gain are achieved. In the invention, advantages of the simple feed, compact structure, low production cost, and the like are realized. The monopulse tracking can simultaneously meet a requirement of a beam wave direction consistency among tracking bands, and track both a linear polarization beacon satellite and a circular polarization beacon satellite. The double-slot-depth tri-band differential mode tracking feed source and the design method thereof can be applicable to the multi-band multi-tracking antenna, and the multi-band multi-tracking common antenna feed sources include, for example, the L / S / C, S / C, C / Ku / Ka /, C / Ku, S / X and X / Ka.

Description

The dark three frequency range differential modes of double flute are followed the tracks of feed and method for designing thereof

Technical field

The present invention relates to the dark three frequency range differential modes of a kind of double flute in communication broadcast, moving target, investigation antagonism, observing and controlling and the navigation field and follow the tracks of feed and method for designing thereof, be specially adapted to that L/S, L/S/C, S/X, S/C, X/Ka etc. need the system of the real-time single-pulse track of multiband or at the unusual various monopulse track antennas under the compacted condition of structural requirement.

Background technology

Along with modern society to the quick growth of satellite communication demand, navigation observation and control technology fast development, the working frequency range of some satellites has developed into two-band, as two-bands such as C/Ku, L/C, S/C, X/Ka and S/X, following multiband development is trend of the times.For the message capacity that enlarges the satellite ground station antenna, reduce the satellite ground station antenna construction cost, reduce ground station's satellite antenna and take up room, the satellite ground station antenna just should possess the while and carry out work in two frequency ranges or multiband.The feed system of antenna also gets and can work in two frequency ranges or multiband simultaneously.Following big medium caliber ground satellite station antenna should possess the above ability to work of two-band, so become particularly important of the technology that develops two-band or multiband feed system.

In order to keep satellite and earth station antenna communication data real-time, therefore require most of earth station antennas all to have the antenna direction follow-up control, so that antenna alignment is around geocyclic satellite.At present the satellite antenna tracking mode mainly adopts: conical scanning tracking, stepping tracking, program designation are followed the tracks of, single-pulse track, and wherein single-pulse track is with characteristics such as its precision height, speed are fast in being widely used in following the tracks of, in the low orbit satellite antenna.Single-pulse track is used many modes and is mainly:

1, four loudspeaker synthesis modes: this is that a kind of principle analysis is clear, handling ease and practical mode, but using this structure in two-band or multiband feed antenna causes the illumination efficiency of antenna low, and maximum shortcoming is that this mode makes the beam position deviation ratio between frequency range and the frequency range bigger, when two-band or multiband real-time tracking, make that switching efficiency is slack-off between two frequency ranges.

2, circular waveguide TE ₂₁The mould mode: this is that a kind of principle analysis is clear, the illumination efficiency height of antenna and the reasonable mode of difference beam consistency, but its shortcoming is: the first, because TE ₂₁The mode coupling device adopts 8 arm coupled waveguide composite structures, and 8 rectangular waveguides are coupled with circular waveguide by 8 row's apertures, causes processed complex, physical dimension big; The second, this tracking mode major part only is suitable for one-segment and follows the tracks of, if use on the two-band as C/Ku on, the C frequency range adopts this tracking mode, will cause the Ku frequency range can't operate as normal so, and therefore this tracking mode can not be applicable to that two-band or multiband follow the tracks of.

3, circular waveguide TM ₀₁The mould mode: this mode is simple and compact for structure, with low cost, polarization is easy to adjust, but this tracking mode shortcoming is: working band is narrow, can only follow the tracks of the circular polarization beacon satellite can't tracker wire polarization beacon satellite.

China Patent No. is 03103242.7, name is called and discloses the shared corrugated horn feed of a kind of dual-slot structure two-band in " the dual-slot structure two-band shares the corrugated horn feed " patent, China Patent No. is 01225820.2, name is called in " the dark corrugated horn feed of high-performance broadband double flute " patent and discloses the dark corrugated horn feed of a kind of high-performance broadband double flute, these two kinds of corrugated horn feeds are double flute deep structure horn feed, and can only transmit main mould HE ₁₁The mould signal of communication is coupled out differential mode HE and be unrealized in the dark corrugated horn of double flute ₂₁Mould, this feed can't be realized the single-pulse track function.

China Patent No. is 90203857.5, and name is called in " antenna feed network equipment " patent and discloses a kind of antenna feed network equipment, and it is mainly by corrugated horn and TM ₀₁Parts such as mode coupling device are formed, and are not to be coupled out differential mode HE in wave groove ₂₁Mould, and can't realize the function of single-pulse track linear polarization beacon satellite.

Summary of the invention

Dual-slot structure three frequency ranges that the objective of the invention is to avoid the weak point in the above-mentioned background technology and provide a kind of energy three frequency range communications, one-segment single-pulse track, three frequency ranges to share share corrugated horn feed and method for designing thereof, and the present invention also has and can have antenna pattern rotation symmetry in the frequency range of three separation, sidelobe level is low, reflection loss is little, gain is high and has realized characteristics such as one-segment single-pulse track function.

The object of the present invention is achieved like this:

The dark three frequency range differential modes of a kind of double flute are followed the tracks of feed, comprise dual-slot structure corrugated horn and differential mode feeder line comprise network, and the dual-slot structure corrugated horn is made up of changeover portion 1, modular transformation section 2, frequency conversion section 3, angular-varying section 4 and radiant section 5; It is characterized in that: the dual-slot structure form of described frequency conversion section 3 for being formed by a plurality of groove cycle, evenly offer first to the 8th coupling aperture 3-1 to 3-8 successively on the circumference of the corresponding corrugated horn in groove cycle place at frequency conversion section middle part, the angle between each coupling aperture is 45 degree.

Wherein, described coupling aperture is radially opened at the bottom of wave groove and is rectangular opening.

Wherein, described differential mode feeder line comprise network comprises that eight low pass filters, eight waveguide coaxial converters, first to the 6th little bands close poor device, little band 3dB electric bridge and coaxial cable; Wherein, the signal of the first coupling aperture 3-1 and the 5th coupling aperture 3-5 output enters first little band respectively and closes poor device 6-1 behind low pass filter and waveguide coaxial converter, first little band closes poor device 6-1 to carry out the two paths of signals that enters to export first via horizontal line polarization branch signal after the addition; The signal of the 3rd coupling aperture 3-3 and the 7th coupling aperture 3-7 output enters second little band respectively and closes poor device 6-2 behind low pass filter and waveguide coaxial converter, second little band closes poor device 6-2 to carry out the two paths of signals that enters to export the second road horizontal line polarization branch signal after the addition; First via horizontal line polarization branch signal and the second road horizontal line polarization branch signal are imported the 3rd little band respectively to be closed poor device 6-3 and subtracts each other and handle back output horizontal line polarized signal;

The signal of the second coupling aperture 3-2 and the 6th coupling aperture 3-6 output enters the 4th little band respectively and closes poor device 6-4 behind low pass filter and waveguide coaxial converter, the 4th little band closes poor device 6-4 to carry out the two paths of signals that enters to export first via vertical line polarization branch signal after the addition; The signal of the 4th coupling aperture 3-4 and the 8th coupling aperture 3-8 output enters the 5th little band respectively and closes poor device 6-5 behind low pass filter and waveguide coaxial converter, the 5th little band closes poor device 6-5 to carry out the two paths of signals that enters to export the second road vertical line polarization branch signal after the addition; First via vertical line polarization branch signal and the second road vertical line polarization branch signal are imported the 6th little band respectively to be closed poor device 6-6 and subtracts each other and handle back output vertical line polarized signal;

Vertical line polarized signal and horizontal polarization signal are through little band 3dB electric bridge 7 output antenna autotracking signals.

Wherein, described coupling aperture be opened on the frequency conversion section from the modular transformation section to the angular-varying section direction the 7th the groove cycle place.

Wherein, frequency conversion section adopts the double flute deep structure form of being made of a groove cycle a dark straight trough and shallow straight trough.

Wherein, the groove depth of coupling aperture position is 1.5 to 2.5 times of normal groove depth.

Wherein, the coupling aperture position of difference mode signal is on the antinodal point of difference mode signal echo.

The method for designing that the dark three frequency range differential modes of a kind of double flute as claimed in claim 1 are followed the tracks of feed is characterized in that may further comprise the steps:

(1) design dual-slot structure three frequency ranges share the corrugated horn feed; Wherein the parameter of deep trouth is that requirement according to the L frequency band signals designs, and the parameter of shallow slot is that the requirement according to the C frequency band signals designs, and S frequency range master mould is propagated in corrugated horn and is equivalent to light wall subtended angle loudspeaker;

(2) share the groove parametric solution L frequency range difference mode signal HE of corrugated horn feed according to dual-slot structure three frequency ranges ₂₁Equivalent admittance Y;

In three frequency ranges shared corrugated horn feed modular transformation section, modular transformation Duan Youhuan loading groove and straight trough were formed, difference mode signal HE ₂₁Equivalent admittance Y _DifferenceComputing formula:

(1) in the formula, b ₁For ring loads the groove width of rebate; b ₂Be the straight trough well width; P is the cycle of dual-slot structure wave groove; Y ₁Be that ring loads the admittance of groove difference mode signal equivalence wall; Y ₂It is the admittance of straight trough differential mode equivalence wall;

In three frequency ranges shared corrugated horn feed frequency conversion section, angular-varying section, radiant section, frequency conversion section, angular-varying section, radiant section all were made up of dark straight trough and shallow straight trough, difference mode signal HE ₂₁Equivalent admittance Y _DifferenceComputing formula:

(2) in the formula, b is the well width of dark straight trough and shallow straight trough; Y ₃It is the admittance of dark straight trough difference mode signal equivalence wall; Y ₄It is the admittance of shallow straight trough differential mode equivalence wall;

(3) with the corrugated waveguide characteristic equation of L frequency range difference mode signal equivalent admittance substitution by the derivation of surface impedance method, solve L frequency range difference mode signal HE ₂₁(m=2, n=1) characteristic value;

(3) in the formula J _m(k ₀A), J ' _m(k ₀A) be respectively the derivative of m rank Bessel function and m rank Bessel function; k ₀A is L frequency range difference mode signal characteristic value; K free space propagation constant; A is the inwall radius at notch place;

(4) with L frequency range difference mode signal characteristic value k ₀The following formula of a substitution solves the propagation constant β of L frequency range difference mode signal _Difference, formula is as follows:

K free space propagation constant in the formula (4); A is the inwall radius at notch place;

(5) judge the position of the critical cut-off point of L frequency range difference mode signal according to the propagation constant of L frequency range difference mode signal, judgment mode is as follows;

Work as β _DifferenceDuring for real number, expression L frequency range differential mode can be propagated in wave groove; Work as β _DifferenceDuring for imaginary number, expression L frequency range differential mode cannot be propagated in wave groove; Work as β _Difference=0 o'clock, expression L frequency range differential mode was critical cut-off point in wave groove;

(6) according to the position of the critical cut-off point of L frequency range difference mode signal and the propagation constant β of L frequency range difference mode signal _Difference, calculating the antinodal point of L frequency range difference mode signal, computing formula is as follows:

S is for beginning the S groove of number in the formula (5) from critical cut-off point; N is for beginning n antinodal point of number from critical cut-off point; λ is free space wavelength;

(7) evenly offer first to the 8th coupling aperture successively on the corrugated horn bottom land circumference at the antinodal point place of L frequency range difference mode signal, the angle between each coupling aperture is 45 degree, and the difference mode signal that coupling aperture is coupled out the L frequency range namely is HE21 mould signal;

(8) the field shape distribution map according to the HE21 pattern designs differential mode feeder line comprise network.

Wherein, the method for designing of the differential mode feeder line comprise network in the step (8) is: first little band is set closes poor device for branch signal that output first via horizontal line after the difference signal addition of first coupling aperture and the 5th coupling aperture output is polarized; Second little band is set closes poor device for branch signal that output the second road horizontal line after the difference signal addition of the 3rd coupling aperture and the 7th coupling aperture output is polarized; The 3rd little band is set to be closed poor device and is used for first via horizontal line polarization branch signal and the second road horizontal line polarization branch signal subtracted each other and handles back output horizontal line polarized signal;

The 4th little band is set to be closed poor device and is used for signal with second coupling aperture and the output of the 6th coupling aperture and carries out output first via vertical line polarization branch signal after the addition; The 5th little band is set to be closed poor device and is used for signal with the 4th coupling aperture and the output of the 8th coupling aperture and carries out output the second road vertical line polarization branch signal after the addition; The 6th little band is set to be closed poor device and first via vertical line polarization branch signal and the second road vertical line polarization branch signal are subtracted each other handles back output vertical line polarized signal;

Little band 3dB electric bridge is set to be used for the vertical line polarized signal that will receive and horizontal polarization signal and to be converted into L frequency range differential mode circularly polarized signal and to export.

The present invention compares with background technology has following advantage:

1. the present invention has adopted frequency conversion section 3 wave grooves, and the frequency changeover portion that these frequency conversion section 3 effects are three frequency range master mould signals is again the coupler of difference mode signal, has solved the separation problem of difference mode signal and main mould signal.

2. the present invention has adopted the groove periodic mode of dual-slot structure, both solved main mould signal work bandwidth, by one dark straight trough 22 and a shallow straight trough 23 form groove and open coupling aperture in one of them dark straight trough 22 in the cycle, successful solution the wave groove bottom land open coupling aperture to whole working band in the influence of main mould signal.

3. the present invention is installed in and both can have realized on the antenna circularly polarized signal is carried out autotracking, also can realize the autotracking of linear polarization signal, simultaneously antenna have also that gain is high, secondary lobe is low, the premium properties such as line circular polarization conversion of low-cross polarization, low axial ratio and antenna.

4. to close poor device 6, little band 3dB electric bridge 7, cable 8, low pass filter 9, waveguide coaxial converter 10 by changeover portion 1, modular transformation section 2, frequency conversion section 3, angular-varying section 4, radiant section 5, little band synthetic in the present invention, realize antenna and difference transmission, the antenna feed size is dwindled significantly, and compact conformation, processing cost are low.

5. success of the present invention remedies several single-pulse track mode weak points in the background technology, realizing the technical of multiband multi-track, can satisfy and follow the tracks of the conforming requirement of beam position between the frequency range and realize the function that can tracker wire polarization beacon satellite also can follow the tracks of the circular polarization beacon satellite.

Description of drawings

Fig. 1 is structural representation of the present invention.

Fig. 2 is modular transformation section 2 internal structure cross-sectional schematic of the present invention.

Fig. 3 is frequency conversion section 3 structural representations of the present invention.

Fig. 4 is the left view of Fig. 3.

Fig. 5 is signal theory diagram of the present invention.

Fig. 6 is signal composition principle block diagram of the present invention.

Embodiment

Below, the invention will be further described in conjunction with Fig. 1 to Fig. 6.

The dark three frequency range differential modes of a kind of double flute are followed the tracks of feed, comprise dual-slot structure corrugated horn and differential mode feeder line comprise network, and the dual-slot structure corrugated horn is made up of changeover portion 1, modular transformation section 2, frequency conversion section 3, angular-varying section 4 and radiant section 5; It is characterized in that: the dual-slot structure form of described frequency conversion section 3 for being formed by a plurality of groove cycle, evenly offer first to the 8th coupling aperture 3-1 to 3-8 successively on the circumference of the corresponding corrugated horn in groove cycle place at frequency conversion section middle part, the angle between each coupling aperture is 45 degree.

Wherein, described coupling aperture is radially opened at the bottom of wave groove and is rectangular opening.

Wherein, described differential mode feeder line comprise network comprises that eight low pass filters, eight waveguide coaxial converters, first to the 6th little bands close poor device, little band 3dB electric bridge and coaxial cable; Wherein, the signal of the first coupling aperture 3-1 and the 5th coupling aperture 3-5 output enters first little band respectively and closes poor device 6-1 behind low pass filter and waveguide coaxial converter, first little band closes poor device 6-1 to carry out the two paths of signals that enters to export first via horizontal line polarization branch signal after the addition; The signal of the 3rd coupling aperture 3-3 and the 7th coupling aperture 3-7 output enters second little band respectively and closes poor device 6-2 behind low pass filter and waveguide coaxial converter, second little band closes poor device 6-2 to carry out the two paths of signals that enters to export the second road horizontal line polarization branch signal after the addition; First via horizontal line polarization branch signal and the second road horizontal line polarization branch signal are imported the 3rd little band respectively to be closed poor device 6-3 and subtracts each other and handle back output horizontal line polarized signal;

The signal of the second coupling aperture 3-2 and the 6th coupling aperture 3-6 output enters the 4th little band respectively and closes poor device 6-4 behind low pass filter and waveguide coaxial converter, the 4th little band closes poor device 6-4 to carry out the two paths of signals that enters to export first via vertical line polarization branch signal after the addition; The signal of the 4th coupling aperture 3-4 and the 8th coupling aperture 3-8 output enters the 5th little band respectively and closes poor device 6-5 behind low pass filter and waveguide coaxial converter, the 5th little band closes poor device 6-5 to carry out the two paths of signals that enters to export the second road vertical line polarization branch signal after the addition; First via vertical line polarization branch signal and the second road vertical line polarization branch signal are imported the 6th little band respectively to be closed poor device 6-6 and subtracts each other and handle back output vertical line polarized signal;

Vertical line polarized signal and horizontal polarization signal are through little band 3dB electric bridge 7 output antenna autotracking signals.

Wherein, described coupling aperture be opened on the frequency conversion section from the modular transformation section to the angular-varying section direction the 7th the groove cycle place.

Wherein, frequency conversion section adopts the double flute deep structure form of being made of a groove cycle a dark straight trough and shallow straight trough.

Wherein, the groove depth of coupling aperture position is 1.5 to 2.5 times of normal groove depth.

Wherein, the coupling aperture position of difference mode signal is on the antinodal point of difference mode signal echo.

The method for designing that the dark three frequency range differential modes of a kind of double flute as claimed in claim 1 are followed the tracks of feed is characterized in that may further comprise the steps:

(1) design dual-slot structure three frequency ranges share the corrugated horn feed; Wherein the parameter of deep trouth is that requirement according to the L frequency band signals designs, and the parameter of shallow slot is that the requirement according to the C frequency band signals designs, and S frequency range master mould is propagated in corrugated horn and is equivalent to light wall subtended angle loudspeaker;

(2) share the groove parametric solution L frequency range difference mode signal equivalent admittance Y of corrugated horn feed according to dual-slot structure three frequency ranges;

In three frequency ranges shared corrugated horn feed modular transformation section, modular transformation Duan Youhuan loading groove and straight trough were formed, difference mode signal HE ₂₁(m=2, n=1) equivalent admittance Y _DifferenceComputing formula:

In the formula (6)

$Y_1=\left\{\frac{b_1}{W_1}\right[V_m^{\′}\left({\mathrm{kd}}_0\right)+B_m]U_{m1}+U_{m2}\}\÷\{1+\frac{b_1}{W_1}[V_m^{\′}\left({\mathrm{kd}}_0\right)+B_m\left]U_{m3}\right\}---\left(7\right)$

$Y_2=\frac{J_m^{\′}\left(\mathrm{ka}\right)N_m\left({\mathrm{kd}}_2\right)-J_m\left({\mathrm{kd}}_2\right)N_m^{\′}\left(\mathrm{ka}\right)}{J_m\left(\mathrm{ka}\right)N_m\left({\mathrm{kd}}_2\right)-J_m\left({\mathrm{kd}}_2\right)N_m\left(\mathrm{ka}\right)}---\left(8\right)$

$V_m^{\′}\left({\mathrm{kd}}_0\right)=\frac{J_m^{\′}\left({\mathrm{kd}}_0\right)N_m\left({\mathrm{kd}}_1\right)-J_m\left({\mathrm{kd}}_1\right)N_m^{\′}\left({\mathrm{kd}}_0\right)}{J_m\left({\mathrm{kd}}_0\right)N_m\left({\mathrm{kd}}_1\right)-J_m\left({\mathrm{kd}}_1\right)N_m\left({\mathrm{kd}}_0\right)}---\left(9\right)$

$U_{m1}=\frac{J_m^{\′}\left(\mathrm{ka}\right)N_m\left({\mathrm{kd}}_0\right)-J_m\left({\mathrm{kd}}_0\right)N_m^{\′}\left(\mathrm{ka}\right)}{J_m^{\′}\left({\mathrm{kd}}_0\right)N_m\left(\mathrm{ka}\right)-J_m\left(\mathrm{ka}\right)N_m^{\′}\left({\mathrm{kd}}_0\right)}---\left(10\right)$

$U_{m2}=\frac{J_m^{\′}\left({\mathrm{kd}}_0\right)N_m^{\′}\left(\mathrm{ka}\right)-J_m^{\′}\left(\mathrm{ka}\right)N_m^{\′}\left({\mathrm{kd}}_0\right)}{J_m^{\′}\left({\mathrm{kd}}_0\right)N_m\left(\mathrm{ka}\right)-J_m\left(\mathrm{ka}\right)N_m^{\′}\left({\mathrm{kd}}_0\right)}---\left(11\right)$

${\mathrm{<figure-callout\; id="3"\; label="U\; m"\; filenames="HDA00003168807400021.png"\; state="\{\{state\}\}">U</figure-callout>}}_m=\frac{J_m\left(\mathrm{ka}\right)N_m\left({\mathrm{kd}}_0\right)-J_m\left({\mathrm{kd}}_0\right)N_m\left(\mathrm{ka}\right)}{J_m^{\&prime;}\left({\mathrm{kd}}_0\right)N_m\left(\mathrm{ka}\right)-J_m\left(\mathrm{ka}\right)N_m^{\&prime;}\left({\mathrm{kd}}_0\right)}---\left(12\right)$

$B_m=\frac{B_P}{Y_0}\sqrt{1-{\left(\frac{\mathrm{\&lambda;}}{{\mathrm{\&lambda;}}_C}\right)}^2}---\left(13\right)$

$\frac{B_P}{Y_0}=\frac{{4W}_1}{{\mathrm{\&lambda;}}_g}\left\{\ln \right[\left(\frac{1-{\mathrm{\&alpha;}}^2}{4\mathrm{\&alpha;}}\right){\left(\frac{1+\mathrm{\&alpha;}}{1-\mathrm{\&alpha;}}\right)}^{\frac{1}{2}(\mathrm{\&alpha;}+\frac{1}{\mathrm{\&alpha;}})}]+2\frac{A+A\&prime;+2C}{\mathrm{AA}\&prime;-C^2}+{\left(\frac{W_1}{{2\mathrm{\&lambda;}}_g}\right)}^2{\left(\frac{1-\mathrm{\&alpha;}}{1+\mathrm{\&alpha;}}\right)}^{4\mathrm{\&alpha;}}{(\frac{{5\mathrm{\&alpha;}}^2-1}{1-{\mathrm{\&alpha;}}^2}+\frac{{4\mathrm{\&alpha;}}^{2}C}{3A})}^2\}---\left(14\right)$

$A={\left(\frac{1+\mathrm{\&alpha;}}{1-\mathrm{\&alpha;}}\right)}^{2\mathrm{\&alpha;}}\frac{1+\sqrt{1-{\left(\frac{{2W}_1}{{\mathrm{\&lambda;}}_g}\right)}^2}}{1-\sqrt{1-{\left(\frac{{2W}_1}{{\mathrm{\&lambda;}}_g}\right)}^2}}-\frac{1+{3\mathrm{\&alpha;}}^2}{1-{\mathrm{\&alpha;}}^2}---\left(15\right)$

$A\&prime;={\left(\frac{1+\mathrm{\&alpha;}}{1-\mathrm{\&alpha;}}\right)}^{\frac{2}{\mathrm{\&alpha;}}}\frac{1+\sqrt{1-{\left(\frac{{2b}_1}{{\mathrm{\&lambda;}}_g}\right)}^2}}{1-\sqrt{1-{\left(\frac{{2b}_1}{{\mathrm{\&lambda;}}_g}\right)}^2}}+\frac{3+{\mathrm{\&alpha;}}^2}{1-{\mathrm{\&alpha;}}^2}---\left(16\right)$

$C={\left(\frac{4\mathrm{\&alpha;}}{1-{\mathrm{\&alpha;}}^2}\right)}^2---\left(17\right)$

λ _C=πd ₀ （18）

${\mathrm{\&lambda;}}_g=\frac{\mathrm{\&lambda;}}{\sqrt{1-{\left(\frac{\mathrm{\&lambda;}}{{\mathrm{\&lambda;}}_C}\right)}^2}}---\left(19\right)$

$\mathrm{\&alpha;}=\frac{b_1}{W_1}---\left(20\right)$

d ₀=a+h ₁/3 （21）

d ₁=a+h ₁ （22）

d ₂=a+h ₂ （23）

J _m(x), N _m(x) be respectively m rank Bessel function and Nuo Yiman function; λ is the wavelength of free space; λ _CBe cut-off wavelength; A is the inwall radius at notch place; b ₁For ring loads groove 21 width of rebate; b ₂Be straight trough 22 well widths; W ₁Load the width of groove 23 for ring; P is the cycle of dual-slot structure wave groove; Y ₁It is the equivalent wall admittance that ring loads groove 24; Y ₂It is the equivalent wall admittance of straight trough 25; H1 loads groove depth for ring; H2 is the straight trough degree of depth;

In three frequency ranges shared the frequency conversion section, angular-varying section, radiant section of corrugated horn feed, frequency conversion section, angular-varying section, radiant section all were made up of dark straight trough and shallow straight trough, difference mode signal HE ₂₁(m=2, n=1) equivalent admittance Y _DifferenceComputing formula:

(24) in the formula, b is the well width of dark straight trough and shallow straight trough; Y ₃It is the admittance of dark straight trough difference mode signal equivalence wall; Y ₄It is the admittance of shallow straight trough differential mode equivalence wall;

${\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="HDA00003168807400021.png"\; state="\{\{state\}\}">Y</figure-callout>}}_3=\frac{J_m^{\&prime;}\left(\mathrm{ka}\right)N_m\left({\mathrm{kd}}_3\right)-J_m\left({\mathrm{kd}}_3\right)N_m^{\&prime;}\left(\mathrm{ka}\right)}{J_m\left(\mathrm{ka}\right)N_m\left({\mathrm{kd}}_3\right)-J_m\left({\mathrm{kd}}_3\right)N_m\left(\mathrm{ka}\right)}---\left(25\right)$

$Y_4=\frac{J_m^{\&prime;}\left(\mathrm{ka}\right)N_m\left({\mathrm{kd}}_4\right)-J_m\left({\mathrm{kd}}_4\right)N_m^{\&prime;}\left(\mathrm{ka}\right)}{J_m\left(\mathrm{ka}\right)N_m\left({\mathrm{kd}}_4\right)-J_m\left({\mathrm{kd}}_4\right)N_m\left(\mathrm{ka}\right)}---\left(26\right)$

d ₃=a+h ₃ （27）

d ₄=a+h ₄ （28）

Y ₃Equivalent wall admittance for deep trouth; Y ₄Equivalent wall admittance for shallow slot; B is the groove width of depth straight trough; A is the inwall radius at notch place; H3 is the dark straight trough degree of depth; H4 is the shallow straight trough degree of depth.

(3) with the corrugated waveguide characteristic equation of L frequency range difference mode signal equivalent admittance substitution by the derivation of surface impedance method, solve L frequency range difference mode signal HE ₂₁(m=2, n=1) characteristic value;

(29) in the formula J ' _m(k ₀A) be the derivative of m rank Bessel function; k ₀A is L frequency range difference mode signal characteristic value; K free space propagation constant; A is the inwall radius at notch place;

(4) with L frequency range difference mode signal characteristic value k ₀The following formula of a substitution solves the propagation constant β of L frequency range difference mode signal _Difference, formula is as follows:

K free space propagation constant in the formula (30); A is the inwall radius at notch place;

(5) judge the position of the critical cut-off point of L frequency range difference mode signal according to the propagation constant of L frequency range difference mode signal, judgment mode is as follows;

Work as β _DifferenceDuring for real number, expression L frequency range differential mode can be propagated in wave groove; Work as β _DifferenceDuring for imaginary number, expression L frequency range differential mode cannot be propagated in wave groove; Work as β _Difference=0 o'clock, expression L frequency range differential mode was critical cut-off point in wave groove;

(6) according to the position of the critical cut-off point of L frequency range difference mode signal and the propagation constant β of L frequency range difference mode signal _Difference, calculating the antinodal point of L frequency range difference mode signal, computing formula is as follows:

S is for beginning the S groove of number in the formula (31) from critical cut-off point; N is for beginning n antinodal point of number from critical cut-off point; λ is free space wavelength;

(7) evenly offer first to the 8th coupling aperture successively on the corrugated horn bottom land circumference at the antinodal point place of L frequency range difference mode signal, the angle between each coupling aperture is 45 degree, and the difference mode signal that coupling aperture is coupled out the L frequency range namely is HE21 mould signal;

(8) the field shape distribution map according to the HE21 pattern designs differential mode feeder line comprise network.

Wherein, the method for designing of the differential mode feeder line comprise network in the step (8) is: first little band is set closes poor device for branch signal that output first via horizontal line after the difference signal addition of first coupling aperture and the 5th coupling aperture output is polarized; Second little band is set closes poor device for branch signal that output the second road horizontal line after the difference signal addition of the 3rd coupling aperture and the 7th coupling aperture output is polarized; The 3rd little band is set to be closed poor device and is used for first via horizontal line polarization branch signal and the second road horizontal line polarization branch signal subtracted each other and handles back output horizontal line polarized signal;

The 4th little band is set to be closed poor device and is used for signal with second coupling aperture and the output of the 6th coupling aperture and carries out output first via vertical line polarization branch signal after the addition; The 5th little band is set to be closed poor device and is used for signal with the 4th coupling aperture and the output of the 8th coupling aperture and carries out output the second road vertical line polarization branch signal after the addition; The 6th little band is set to be closed poor device and first via vertical line polarization branch signal and the second road vertical line polarization branch signal are subtracted each other handles back output vertical line polarized signal;

Little band 3dB electric bridge is set to be used for the vertical line polarized signal that will receive and horizontal polarization signal and to be converted into L frequency range differential mode circularly polarized signal and to export.

According to the method for designing that the dark three frequency range differential modes of above-mentioned double flute are followed the tracks of feed, embodiment design and L/S/C three frequency ranges of having made for 13 meters antennas share L frequency range differential mode tracking Behaviors of Corrugated Feeds.Measured result shows, L/S/C three frequency ranges share L frequency range differential mode follow the tracks of Behaviors of Corrugated Feeds can be in three frequency ranges of separating of L, S and C (L frequency range: 1.167～1.6GHz; S frequency range: 2.18～2.5GHz; C frequency range: 3.8～4.05GHz, 6～6.3GHz) produce the rotational symmetric antenna pattern of directional diagram of main mould, and cross polarization level is less than-20dB, and reflection loss is better than 18dB.Differential mode tracking frequency (L frequency range: the rotational symmetric antenna pattern of 1.551～1.571GHz) directional diagram, in following the tracks of frequency range and the gain inequality of directional diagram and difference directional diagram about-19dB, 13 meters antennas making feed with these loudspeaker have been realized antenna single-pulse track function and the tracking accuracy requirement of having satisfied 1/20 beamwidth in the L frequency range.

Claims (9)

1. the dark three frequency range differential modes of double flute are followed the tracks of feed, comprise dual-slot structure corrugated horn and differential mode feeder line comprise network, and the dual-slot structure corrugated horn is made up of changeover portion (1), modular transformation section (2), frequency conversion section (3), angular-varying section (4) and radiant section (5); It is characterized in that: the dual-slot structure form of described frequency conversion section (3) for being formed by a plurality of groove cycle, evenly offer first to the 8th coupling aperture (3-1 to 3-8) successively on the circumference of the corresponding corrugated horn in groove cycle place at frequency conversion section middle part, the angle between each coupling aperture is 45 degree.

2. the dark three frequency range differential modes of double flute according to claim 1 are followed the tracks of feed, and it is characterized in that: described coupling aperture is radially opened at the bottom of wave groove and is rectangular opening.

3. the dark three frequency range differential modes of double flute according to claim 1 are followed the tracks of feed, and it is characterized in that: described differential mode feeder line comprise network comprises that eight low pass filters, eight waveguide coaxial converters, first to the 6th little bands close poor device, little band 3dB electric bridge and coaxial cable; Wherein, the signal of first coupling aperture (3-1) and the 5th coupling aperture (3-5) output enters first little band respectively and closes poor device (6-1) behind low pass filter and waveguide coaxial converter, first little band closes poor device (6-1) to carry out the two paths of signals that enters to export first via horizontal line polarization branch signal after the addition; The signal of the 3rd coupling aperture (3-3) and the 7th coupling aperture (3-7) output enters second little band respectively and closes poor device (6-2) behind low pass filter and waveguide coaxial converter, second little band closes poor device (6-2) to carry out the two paths of signals that enters to export the second road horizontal line polarization branch signal after the addition; First via horizontal line polarization branch signal and the second road horizontal line polarization branch signal are imported the 3rd little band respectively to be closed poor device (6-3) and subtracts each other and handle back output horizontal line polarized signal;

The signal of second coupling aperture (3-2) and the 6th coupling aperture (3-6) output enters the 4th little band respectively and closes poor device (6-4) behind low pass filter and waveguide coaxial converter, the 4th little band closes poor device (6-4) to carry out the two paths of signals that enters to export first via vertical line polarization branch signal after the addition; The signal of the 4th coupling aperture (3-4) and the 8th coupling aperture (3-8) output enters the 5th little band respectively and closes poor device (6-5) behind low pass filter and waveguide coaxial converter, the 5th little band closes poor device (6-5) to carry out the two paths of signals that enters to export the second road vertical line polarization branch signal after the addition; First via vertical line polarization branch signal and the second road vertical line polarization branch signal are imported the 6th little band respectively to be closed poor device (6-6) and subtracts each other and handle back output vertical line polarized signal;

Vertical line polarized signal and horizontal polarization signal are through little band 3dB electric bridge (7) output antenna autotracking signal.

4. the dark three frequency range differential modes of double flute according to claim 1 are followed the tracks of feed, it is characterized in that: described coupling aperture is opened on the frequency conversion section from the modular transformation section the 7th the groove cycle to the angular-varying section direction and locates.

5. the dark three frequency range differential modes of double flute according to claim 1 are followed the tracks of feed, it is characterized in that: the frequency conversion section adopts the double flute deep structure form of being made of a groove cycle a dark straight trough and shallow straight trough.

6. the dark three frequency range differential modes of double flute according to claim 1 are followed the tracks of feed, and it is characterized in that: the groove depth of coupling aperture position is 1.5 to 2.5 times of normal groove depth.

7. the dark three frequency range differential modes of double flute according to claim 1 are followed the tracks of feed, and it is characterized in that: the coupling aperture position of difference mode signal is on the antinodal point of difference mode signal echo.

8. the dark three frequency range differential modes of a double flute as claimed in claim 1 method for designing of following the tracks of feed is characterized in that may further comprise the steps:

(1) design dual-slot structure three frequency ranges share the corrugated horn feed; Wherein the parameter of deep trouth is that requirement according to the L frequency band signals designs, and the parameter of shallow slot is that the requirement according to the C frequency band signals designs, and S frequency range master mould is propagated in corrugated horn and leveled off to light wall subtended angle loudspeaker;

(2) share the groove parametric solution L frequency range difference mode signal equivalent admittance Y of corrugated horn feed according to dual-slot structure three frequency ranges;

In three frequency ranges shared corrugated horn feed modular transformation section, modular transformation Duan Youhuan loading groove and straight trough were formed, difference mode signal HE21 equivalent admittance Y _DifferenceComputing formula:

(1) in the formula, b ₁For ring loads the groove width of rebate; b ₂Be the straight trough well width; P is the cycle of dual-slot structure wave groove; Y ₁Be that ring loads the admittance of groove difference mode signal equivalence wall; Y ₂It is the admittance of straight trough differential mode equivalence wall;

In three frequency ranges shared corrugated horn feed frequency conversion section, angular-varying section, radiant section, frequency conversion section, angular-varying section, radiant section all were made up of dark straight trough and shallow straight trough, difference mode signal HE ₂₁Equivalent admittance Y _DifferenceComputing formula:

(2) in the formula, b is the well width of dark straight trough and shallow straight trough; Y ₃It is the admittance of dark straight trough difference mode signal equivalence wall; Y ₄It is the admittance of shallow straight trough differential mode equivalence wall;

(3) with the corrugated waveguide characteristic equation of L frequency range difference mode signal equivalent admittance substitution by the derivation of surface impedance method, solve L frequency range difference mode signal HE ₂₁(m=2, n=1) characteristic value;

(3) in the formula

J _m(k ₀A),

Be respectively the derivative of m rank Bessel function and m rank Bessel function; k ₀A is L frequency range difference mode signal characteristic value; K free space propagation constant;

A is the inwall radius at notch place;

(4) with L frequency range difference mode signal characteristic value k ₀The following formula of a substitution solves the propagation constant β of L frequency range difference mode signal _Difference, formula is as follows:

K free space propagation constant in the formula (4); A is the inwall radius at notch place;

(5) judge the position of the critical cut-off point of L frequency range difference mode signal according to the propagation constant of L frequency range difference mode signal, judgment mode is as follows;

Work as β _DifferenceDuring for real number, expression L frequency range differential mode can be propagated in wave groove; Work as β _DifferenceDuring for imaginary number, expression L frequency range differential mode cannot be propagated in wave groove; Work as β _Difference=0 o'clock, expression L frequency range differential mode was critical cut-off point in wave groove;

(6) according to the position of the critical cut-off point of L frequency range difference mode signal and the propagation constant β of L frequency range difference mode signal _Difference, calculating the antinodal point of L frequency range difference mode signal, computing formula is as follows:

S is for beginning the S groove of number in the formula (5) from critical cut-off point; N is for beginning n antinodal point of number from critical cut-off point; λ is free space wavelength;

(7) evenly offer first to the 8th coupling aperture successively on the corrugated horn bottom land circumference at the antinodal point place of L frequency range difference mode signal, the angle between each coupling aperture is 45 degree, and the difference mode signal that coupling aperture is coupled out the L frequency range namely is HE21 mould signal;

(8) the field shape distribution map according to the HE21 pattern designs differential mode feeder line comprise network.

9. the dark three frequency range differential modes of double flute according to claim 8 are followed the tracks of the method for designing of feed, and it is characterized in that: the method for designing of the differential mode feeder line comprise network in the step (8) is: first little band is set closes poor device and be used for the branch signal that polarizes of output first via horizontal line after the difference signal addition of first coupling aperture and the 5th coupling aperture output; Second little band is set closes poor device for branch signal that output the second road horizontal line after the difference signal addition of the 3rd coupling aperture and the 7th coupling aperture output is polarized; The 3rd little band is set to be closed poor device and is used for first via horizontal line polarization branch signal and the second road horizontal line polarization branch signal subtracted each other and handles back output horizontal line polarized signal;

The 4th little band is set to be closed poor device and is used for signal with second coupling aperture and the output of the 6th coupling aperture and carries out output first via vertical line polarization branch signal after the addition; The 5th little band is set to be closed poor device and is used for signal with the 4th coupling aperture and the output of the 8th coupling aperture and carries out output the second road vertical line polarization branch signal after the addition; The 6th little band is set to be closed poor device and first via vertical line polarization branch signal and the second road vertical line polarization branch signal are subtracted each other handles back output vertical line polarized signal;

Little band 3dB electric bridge is set to be used for the vertical line polarized signal that will receive and horizontal polarization signal and to be converted into L frequency range differential mode circularly polarized signal and to export.

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