CN104852775A - Rapid evaluation method for large phased-array antenna wave beam performance - Google Patents

Abstract

The invention discloses a rapid evaluation method for a large phased-array antenna wave beam performance. With the method, a waveform performance of a large array antenna cab be evaluated rapidly and accurately. A small area array antenna with identical antenna unit arrangement mode, antenna unit distance, antenna unit structural mode with those of a large planar phased-array antenna is manufactured; whether the antenna unit of the large phased-array antenna is designed to be reasonable is checked based on the waveform performance of the small area array antenna and that is, whether a scanning blind point occurs is checked; the amplitude and phase of the center unit of the small area array antenna are used as the amplitude and phase of each antenna unit in the area array of the large planar phased-array antenna and a synthesis power P is calculated; and the waveform characteristic of the large planar phased-array antenna is evaluated by using the synthesis power P.

Description

A kind of fast evaluation method of massive phased array antenna beam performance

Technical field

The present invention relates to phased array antenna technical field, be specifically related to a kind of fast evaluation method of massive phased array antenna beam performance.

Background technology

Larger by the impact of antenna element performance in system phased array antenna system used performances such as communication, radars at present, particularly large-scale array, the wave beam performance of unit has a strong impact on the scan characteristic of front, in order to assess the wave beam performance of front, generally takes as under type:

1) utilize electromagnetic simulation software to carry out full front simulation analysis, be conducive to the cost of manufacture reducing early stage like this, but this depends on the performance of computer very much, and simulation calculation personnel are to the usage degree of simulation software.

2) whole front is connected in the lump with the active equipment of rear end, carry out object test, being conducive to of doing like this knows the real situation to the front performance of reality, also be the state closest to final utilization, but the cost that this mode spends is too high, once deviation appears in the design at initial stage, large loss will be brought.

Summary of the invention

In view of this, the invention provides a kind of fast evaluation method of massive phased array antenna beam performance, the wave beam performance of large-sized array array antenna can be assessed quickly and accurately.

The fast evaluation method of massive phased array antenna beam performance of the present invention, comprises the steps:

Step 1, the antenna element arrangement mode identical with large-scale Planar Phased Array Antenna, antenna element separation, antenna unit structure form is adopted to make partial array antenna, wherein, the face battle array scale of partial array antenna is 1/10 ~ 1/5 of large-scale Planar Phased Array Antenna face battle array scale, and the ranks number of partial array antenna plane is odd number;

Step 2, test obtains amplitude and the phase information of all antenna elements on partial array antenna;

Step 3, the phase information of all antenna elements on partial array antenna is compensated for as unanimously, carry out Beam synthesis, obtain the Beam synthesis directional diagram of partial array antenna, observe partial array antenna whether to occur scanning blind spot, if scanning blind spot appears in partial array antenna, then show that the antenna element of large-scale Planar Phased Array Antenna needs to redesign, now, then according to newly-designed large-scale Planar Phased Array Antenna again from step 1; If do not occur scanning blind spot, then carry out step 4;

Step 4, using the amplitude of partial array center of antenna unit and phase place as the amplitude of each antenna element in the face battle array of large-scale Planar Phased Array Antenna and phase place, calculates synthesis power P:

Wherein, N, M are the ranks number of large-scale Planar Phased Array Antenna face battle array, and P, Q are the ranks number of partial array antenna plane, for partial array center of antenna unit amplitude; for partial array center of antenna unit phase place; (x _n, y _n) be the coordinate figure of antenna element (n, m) on plane coordinate system x-y, for the angle of antenna scanning, k is propagation constant;

Step 5, the synthesis power P that step 4 obtains is similar to the synthesis power being equal to large-scale Planar Phased Array Antenna, thus the synthesis power P adopting step 4 to obtain assesses the beam feature of large-scale Planar Phased Array Antenna.

Further, the phase compensating method of the antenna element (n, m) on the medium and small planar array of step 3 is as follows:

Step 3.1, initial time partial array antenna is just to feed;

Step 3.2, arbitrarily angled rotation partial array antenna, according to the phase difference ΔΦ of the angle calculation antenna element (n, m) rotated with center cell _nm, with phase difference ΔΦ _nmfor the phase compensation amount of antenna element (n, m) compensates;

Wherein, when front rotates counterclockwise angle θ " time, wherein, λ is the electromagnetic wavelength of antenna propagation; L is the distance of partial array antenna array center unit to feed; S " be now antenna element (n, m) to the distance of feed, d _nmfor antenna element (n, m) is to the distance of center cell;

When front rotates clockwise angle θ ', s ' be now antenna element (n, m) to the distance of feed, $S^{\′}=\sqrt{L^2+d_{\mathrm{nm}}^2-2{\mathrm{Ld}}_{\mathrm{nm}}\cos (\mathrm{\π}/2+{\mathrm{\θ}}^{\′})}.$

Beneficial effect:

(1) the present invention utilizes the partial array of design can the wave beam performance of the large planar array of rapid evaluation, appraisal procedure simple possible, and efficiency is high; And the technology adopting object test to combine with theoretical simulation, avoids pure theoretical simulation and tests with actual the shortcoming that there is deviation, it also avoid the difficulty of machining large phased array antenna, reduce design cost simultaneously.

(2) adopt phase compensation amount computational methods of the present invention, partial array in appraisal procedure can be made only to relate to antenna element, and do not need the auxiliary equipment such as extra feeding network, active radio frequency device, cost is low, and efficiency is high, does not limit by components and parts.

Accompanying drawing explanation

Fig. 1 is phased array antenna partial array wave beam performance test figure.

Fig. 2 is the amplitude-phase relation schematic diagram of phased array antenna partial array diverse location unit.

Wherein, 1-partial array, the rotating shaft of 2-antenna rotating platform, 3-test cable I, 4-control appliance, 5-vector network analyzer, 6-test cable II, 7-feed, array center's unit of 8-partial array, the individual unit of 9-partial array (n, m).

Fig. 3 is flow chart of the present invention.

Embodiment

To develop simultaneously embodiment below in conjunction with accompanying drawing, describe the present invention.

The invention provides a kind of fast evaluation method of massive phased array antenna beam performance, first a partial array antenna containing same antenna cell parameters is made according to the relevant parameter of the antenna element of large-scale Planar Phased Array Antenna, then wave beam Performance Evaluation is carried out to this partial array antenna, and then utilize the wave beam performance of partial array antenna to carry out analogy and recursion, be finally inversed by the wave beam performance of large-scale Planar Phased Array Antenna.

Concrete steps are as follows:

Step 1, adopts the antenna element arrangement mode identical with large-scale Planar Phased Array Antenna, antenna element separation, antenna unit structure form to make partial array antenna.

The front scale of massive phased array antenna be N × M (N, M are ranks number, General N, M be greater than 20 natural number), planar arrangement on plane coordinate system x-y, assuming that the version of each antenna element is consistent, then wave beam can be expressed as:

Wherein, for the lobe pattern that position is the antenna element (n, m) that n-th line m arranges, x _nfor antenna element (n, m) coordinate figure in the x direction, y _nfor antenna element (n, m) coordinate figure in y-direction, for the angle of antenna scanning, k is propagation constant.

The front scale of partial array antenna is P × Q (P, Q are ranks number, and P≤N, Q≤M, P × Q is 1/10 ~ 1/5 of N × M, generally gets odd number), only has antenna element, without the need to the auxiliary device such as feeding network, active device in this little front.

Step 2, carries out amplitude and phase measurement to antenna elements all on partial array, obtains amplitude and the phase information of each antenna element of partial array.During test, P × Q-1 matched load is connected on partial array antenna P × Q-1 antenna element, tested antenna connecting test equipment, the load of non-observation line matching connection.

According to its far field condition of property calculation of partial array antenna element, and utilize this far field condition to test the lobe pattern of each unit one by one, comprise amplitude and phase place two category information.

(n, m) individual unit is at test angle (Φ ₁, Φ ₂) in electric field signal be:

$E_{\mathrm{nm}}=A_{\mathrm{nm}}{e}^{j{\mathrm{\Φ}}_{\mathrm{nm}}}$

Wherein set t as gathering (Φ ₁, Φ ₂) in t sampled point, amplitude phase place t is set (Φ ₁, Φ ₂) in sampling number.

Step 3, the phase compensation of each antenna element of partial array step 2 obtained is after same phase place, carries out the Beam synthesis of partial array, obtains the Beam synthesis directional diagram of partial array:

Wherein, A _nmfor the amplitude of the antenna element (n, m) that step 2 test obtains; Φ _nmfor the phase place of the antenna element (n, m) that step 2 test obtains, ΔΦ _nmfor the phase compensation amount of antenna element (n, m).

The wave beam performance of partial array can be calculated by formula (1), comprise the sweep limits of partial array, gain loss in different scanning angle and occur the characteristic such as scanning blind spot (note: scanning blind spot depends on the design of antenna element) of the larger change of gain.If some angle in sweep limits occurs scanning blind spot, then show that the antenna element of large-scale Planar Phased Array Antenna needs to redesign, now, then according to new large-scale Planar Phased Array Antenna again from step 1.If do not occur scanning blind spot, then carry out step 4.

In this step, when compensating the phase place of each antenna element of partial array that step 2 obtains, active device can be adopted directly to obtain compensation rate; Also can not adopt active device, adopt and obtain compensation rate ΔΦ with the following method _nm:

Step 3.1: little front amplitude-phase measuring system as shown in Figure 1, the emission port of vector network analyzer 5 connects the feed 7 transmitted by test cable 6, and send the signal of setpoint frequency, partial array 1 Received signal strength, utilize the rotating shaft 2 of control appliance 4 control antenna turntable, partial array 1 is rotated in the test space, and Received signal strength enters the receiving port of vector network analyzer 5 through test cable 3, the lobe amplitude A in space and phase place Φ characteristic is collected.Assuming that the position of array center's cell distance feed 7 remains constant, be L; And remaining unit, if its coordinate is B, the distance of distance center unit is d; Along with the rotational angle of the rotating shaft 2 of antenna rotating platform changes, there is certain skew S in the position of B point distance feed 7.

Step 3.2: the phase relation turning to zones of different at front is different, and given rotational region is divided into I district (front rotates counterclockwise) and II district (front rotates clockwise), as shown in Figure 2.

For (n, m) individual antenna element 9, initial time partial array 1 is just to feed 7, antenna element (n, m) 9 is S to the distance of feed, when front rotates counterclockwise angle θ "; when being in I district, antenna element (n, m) 9 is to the distance S of feed " should be:

$S^{\′\′}=\sqrt{L^2+d_{\mathrm{nm}}^2-2{\mathrm{Ld}}_{\mathrm{nm}}\cos (\mathrm{\π}/2-{\mathrm{\θ}}^{\′\′})}$

Wherein, L is the distance of array center's unit 8 to feed 7, d _nmfor antenna element (n, m) is to the distance of center cell, θ " can be expressed as t=1,2 ... T.

Now antenna element (n, m) 9 can be expressed as with the phase difference of center cell 8:

${\mathrm{\Φ}}_{\mathrm{nm}}^{\′\′t}=\frac{2\mathrm{\π}}{\mathrm{\λ}}(S^{\′\′}-L)$

When front rotates clockwise angle θ ', when being in II district, antenna element (n, m) 9 to the distance S ' of feed is:

$S^{\′}=\sqrt{L^2+d_{\mathrm{nm}}^2-2{\mathrm{Ld}}_{\mathrm{nm}}\cos (\mathrm{\π}/2+{\mathrm{\θ}}^{\′})}$

Wherein θ ' can be expressed as t=1,2 ... T.

Antenna element (n, m) 9 is same with the phase difference of center cell 8 can be expressed as:

${\mathrm{\Φ}}_{\mathrm{nm}}^{\′t}=\frac{2\mathrm{\π}}{\mathrm{\λ}}(S^{\′}-L)$

Will with be collectively expressed as ΔΦ _nm.

Therefore relative to center cell 8, the electric field expression formula of antenna element (n, m) 9 is:

$E_{\mathrm{nm}}=A_{00}{e}^{j({\mathrm{\Φ}}_{00}-\mathrm{\Δ}{\mathrm{\Φ}}_{\mathrm{nm}})}$

Wherein, A ₀₀centered by the amplitude vector of unit 8, Φ ₀₀centered by the phase vectors of unit 8, when turning to Ith district, when turning to IIth district,

Step 4, according to the Performance Evaluation of above-mentioned partial array large battle array performance.

The number of unit total due to partial array is less, the ratio that the number of its surrounding unit accounts for total number of unit is larger, the impact of its edge effect on its performance is larger, and the ratio that the number of unit of large face battle array surrounding accounts for whole front number is less, therefore its edge effect is less, and all element characteristicss of large face battle array are almost consistent, the pattern characteristics of cyclic array can be drawn after carrying out Beam synthesis according to the unit group battle array that Floquet principle-beam feature is consistent, therefore when carrying out the assessment of large-scale array, beam of unit characteristic for array inside can select the width of the test gained of partial array center cell 8 lobe to be worth alternative mutually, its expression formula is:

Through type (2), can go out the sweep limits of large face battle array by approximate evaluation, and in different scanning angle gain loss characteristic.

In sum, for the radiation characteristic obtaining massive phased array antenna needs usually in the test of large test field, and be aided with a large amount of equipment and the good external condition of Electro Magnetic Compatibility, this has higher requirement for cost overhead.In order to reduce its testing cost, and obtaining higher data referential, the present invention proposes a kind of method utilizing the antenna performance of partial array to obtain large-sized array surface radiation characteristic, for practical engineering application, there is higher reference value.

In sum, these are only preferred embodiment of the present invention, be not intended to limit protection scope of the present invention.Within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (2)

1. a fast evaluation method for massive phased array antenna beam performance, is characterized in that, comprises the steps:

Step 1, the antenna element arrangement mode identical with large-scale Planar Phased Array Antenna, antenna element separation, antenna unit structure form is adopted to make partial array antenna, wherein, the face battle array scale of partial array antenna is 1/10 ~ 1/5 of large-scale Planar Phased Array Antenna face battle array scale, and the ranks number of partial array antenna plane is odd number;

Step 2, test obtains amplitude and the phase information of all antenna elements on partial array antenna;

Step 3, the phase information of all antenna elements on partial array antenna is compensated for as unanimously, carry out Beam synthesis, obtain the Beam synthesis directional diagram of partial array antenna, observe partial array antenna whether to occur scanning blind spot, if scanning blind spot appears in partial array antenna, then show that the antenna element of large-scale Planar Phased Array Antenna needs to redesign, now, then according to newly-designed large-scale Planar Phased Array Antenna again from step 1; If do not occur scanning blind spot, then carry out step 4;

Step 4, using the amplitude of partial array center of antenna unit and phase place as the amplitude of each antenna element in the face battle array of large-scale Planar Phased Array Antenna and phase place, calculates synthesis power P:

Wherein, N, M are the ranks number of large-scale Planar Phased Array Antenna face battle array, and P, Q are the ranks number of partial array antenna plane, for partial array center of antenna unit amplitude; for partial array center of antenna unit phase place; (x _n, y _n) be the coordinate figure of antenna element (n, m) on plane coordinate system x-y, for the angle of antenna scanning, k is propagation constant;

Step 5, the synthesis power P that step 4 obtains is similar to the synthesis power being equal to large-scale Planar Phased Array Antenna, thus the synthesis power P adopting step 4 to obtain assesses the beam feature of large-scale Planar Phased Array Antenna.

2. the fast evaluation method of massive phased array antenna beam performance as claimed in claim 1, it is characterized in that, the phase compensating method of the antenna element (n, m) on the medium and small planar array of described step 3 is as follows:

Step 3.1, initial time partial array antenna is just to feed;

Step 3.2, arbitrarily angled rotation partial array antenna, according to the phase difference ΔΦ of the angle calculation antenna element (n, m) rotated with center cell _nm, with phase difference ΔΦ _nmfor the phase compensation amount of antenna element (n, m) compensates;

Wherein, when front rotates counterclockwise angle θ " time, wherein, λ is the electromagnetic wavelength of antenna propagation; L is the distance of partial array antenna array center unit to feed; S " be now antenna element (n, m) to the distance of feed, d _nmfor antenna element (n, m) is to the distance of center cell;

When front rotates clockwise angle θ ', s ' be now antenna element (n, m) to the distance of feed, $S^{\′}=\sqrt{L^2+d_{\mathrm{nm}}^2-2{\mathrm{Ld}}_{\mathrm{nm}}\cos (\mathrm{\π}/2+{\mathrm{\θ}}^{\′})}.$