CN106299726A - A kind of implementation method of phased array uniform speed scanning based on arcsine clock - Google Patents

Abstract

The invention provides the implementation method of a kind of phased array uniform speed scanning based on arcsine clock, first select sweep limits, scanning speed, phase shifter stepping accuracy and array antenna basic parameter；Then excitation phase difference range between adjacent array element, the maximum change frequency of phase shifter and time that in the cycle, each saltus step of phase shifter phase place is corresponding in 1/2 scan period are obtained；Finally realize the uniform speed scanning of phased array main lobe beam position.The present invention utilizes arcsine clock signal to control the phase shifter at non-uniform temporal intervals equivalent change array element excitation phase, realize the uniform speed scanning of phased array antenna, the phased array antenna uniform speed scanning contributing to realizing the sequential operation amount of phase shifter control system in high scanning accuracy, feeding network less controls, simplify the design complexities of hardware circuit, have the highest using value in communications fields such as radar, microwave landings.

Description

A kind of implementation method of phased array uniform speed scanning based on arcsine clock

Technical field

The present invention relates to phased-array antenna, relate to a kind of phased array uniform speed scanning side being applied to microwave landing system Method.

Background technology

Phased array antenna is mainly used in radar or the navigator in the fields such as ground, boats and ships, aerospace, logical Cross and control in array antenna the current feed phase of radiating element to change pattern shapes.Control phase place and can change antenna radiation pattern The sensing of maximum, to reach the purpose of beam scanning.

Uniform speed scanning phased array antenna is the phased array of a kind of antenna pattern main lobe beam position even variation in time Antenna, is applied to microwave landing system (MLS:Microwave Landing System) more.Microwave landing system is for requiring The aircraft in land provides angle guidance information, guides equipment and range finding answering equipment, wherein antenna including bearing directing equipment, the elevation angle Being that whole system signal launches the vitals received, particularly azimuth scan antenna and Elevation Scanning antenna is phased array sky Line, realizes one-dimensional scanning at horizontal plane, vertical guide respectively, forms narrow beam, the scanning plane shape of Sidelobe.Sky launched by ground installation Line is uniform speed scanning phased array system, is transmitted in the wave beam of uniform speed scanning back and forth in the range of certain angle, and airborne receiving equipment connects Receiving " coming ", two burst pulses of " returning " scanning generation, by measuring the time interval of two adjacent signal pulses, combined ground is even Speed phased array beam points to and the relation of time change, it can be determined that the angle guidance information needed for aircraft landing.Therefore, phased The research of the uniform speed scanning characteristic of array antenna has very important significance.

For uniform speed scanning phased array antenna, it is possible to use beam steering system is that numeral is moved in the moment of constant duration Phase device provides and triggers signal, makes the change array element excitation phase that the phase shifter is uneven, it is achieved beam position even variation in time, But this method requires to use the digital phase shifter of higher stepping accuracy could meet in high precision beam scanning, and digital phase shifter Stepping accuracy is the highest, then cost is the highest.

Summary of the invention

In order to overcome the deficiencies in the prior art, the present invention provides a kind of phased array uniform speed scanning based on arcsine clock Implementation method, utilizes the clock signal of arcsine transformation to control the phase shifter, makes the phase shifter change in non-uniform temporal intervals equivalent Array element excitation phase, it is achieved the uniform speed scanning of phased array antenna.

The technical solution adopted for the present invention to solve the technical problems includes following step:

1) sweep limits, scanning speed, phase shifter stepping accuracy and array are selected according to phase-array scanning property requirements Antenna parameter；

2) according to array antenna array factor maximum condition, excitation phase difference range between adjacent array element is obtained；

3) utilize excitation phase difference range and phase shifter stepping accuracy, obtain 1/2 scan period underexcitation phase place maximum Change number of timesWherein, (α_min, α_max) it is adjacent array element phase range in battle array, Δ=2 pi/2^k For phase shifter stepping accuracy,It is to round up；

4) revise array antenna array factor maximum condition, obtain phased array array factor maximum expression formula:

$\left\{\begin{array}{cc}\mathrm{\&beta;}dsin\left({\mathrm{\&theta;}}_m\right)={\mathrm{\&alpha;}}_{min}+p\mathrm{\&Delta;}& (0\&le;p\&le;P)\\ \mathrm{\&beta;}dsin\left({\mathrm{\&theta;}}_m\right)={\mathrm{\&alpha;}}_{max}-(p-P)\mathrm{\&Delta;}& (P<p\&le;2P)\end{array}\right.$

Wherein,

${\mathrm{\&theta;}}_m=\left\{\begin{array}{cc}{\mathrm{\&theta;}}_{\min }+\mathrm{\&omega;}t& (0\&le;t\&le;T_s/2)\\ {\mathrm{\&theta;}}_{\max }-\mathrm{\&omega;}(t-T_s/2)& (T_s/2<t\&le;T_s)\end{array}\right.$

Wherein β is electromagnetic wave free-space propagation constant, and d is adjacent array element distance, θ_mFor array radiation patterns wave beam Pointing to, p is phase shifter phase place change frequency, (θ_min, θ_max) it is phase-array scanning scope, ω is phase-array scanning speed, and t is to sweep Retouch time variable, T_s=2 π/ω is the uniform speed scanning phase-array scanning cycle；

5) by step 1), 3) in parameter be brought into step 4) phased array array factor maximum expression formula, draw one Time series t={t that in scan period, the change of each excitation phase is corresponding₁, t₂..., t_p, t_p+1..., t_2P-1, t_2P}；

6) by time series t divided by clock signal of system cycle T_CLK, obtain a scan period underexcitation phase place change right The arcsine clock sequence answered

Count={count₁, count₂..., count_P, count_P+1..., count_2P-1, count_2P}；

7) in the scan period, whenever the numerical value of control system impulse scaler is equal to step 6) in arcsine sequence Some numerical value time, uniformly change excitation phase phase-shift phase, make phased array main lobe beam position within a scan period even Speed scanning, finally realizes the uniform speed scanning of phased array.

The invention has the beneficial effects as follows: can be phased by selecting phase shifter phase quantization figure place to control uniform speed scanning flexibly The scanning accuracy of battle array, it is also possible to by regulation scanning speed and scanning angle scope, be met the most phased of expection requirement Array 1 system.

The whole process of the present invention utilizes the clock signal of arcsine transformation to control the phase shifter, and equivalent changes array element excitation phase Position, contributes to realizing the phased array antenna that the sequential operation amount of phase shifter control system in high scanning accuracy, feeding network is less Uniform speed scanning controls, and simplifies the design complexities of hardware circuit.

Equivalent of the present invention changes excitation phase value, and scanning accuracy is high, decreases the operand of system program, simplifies hardware electricity Road is designed.

The present invention controls phase shifter equivalent by the clock signal of arcsine transformation and changes array element excitation phase, makes excitation phase Position transformation period is arcsine relation with change frequency, it is achieved the scanning angle phased array linear with the time is at the uniform velocity swept Retouch.

Accompanying drawing explanation

Fig. 1 is the method flow block diagram of the present invention.

Fig. 2 be the embodiment of the present invention about centrosymmetric uniform linear array of antennas schematic diagram.

Fig. 3 is the at the uniform velocity phased array antenna feeding network schematic diagram of the embodiment of the present invention.

In the scan period that Fig. 4 is the embodiment of the present invention, array element excitation phase changes the time and changes the relation of number of times Schematic diagram.

Fig. 5 is the main lobe beam position relation signal with sweep time of the uniform speed scanning phased array of the embodiment of the present invention Figure.

Detailed description of the invention

The present invention is further described with embodiment below in conjunction with the accompanying drawings, and the present invention includes but are not limited to following enforcement Example.

The present invention includes following step:

1) sweep limits, scanning speed, phase shifter stepping accuracy and array are selected according to phase-array scanning property requirements Antenna basic parameter；

2) according to array antenna array factor maximum condition, excitation phase difference range between adjacent array element is obtained；

3) utilize excitation phase difference range and phase shifter stepping accuracy, obtain 1/2 scan period underexcitation phase place maximum Change the expression formula of number of times P

Wherein, (α_min, α_max) it is adjacent array element phase range in battle array, Δ=2 pi/2^kFor phase shifter stepping accuracy, k is Phase quantization figure place,It is to round up；

4) revise array antenna array factor maximum condition, obtain phased array array factor maximum expression formula:

$\left\{\begin{array}{cc}\mathrm{\&beta;}dsin\left({\mathrm{\&theta;}}_m\right)={\mathrm{\&alpha;}}_{min}+p\mathrm{\&Delta;}& (0\&le;p\&le;P)\\ \mathrm{\&beta;}dsin\left({\mathrm{\&theta;}}_m\right)={\mathrm{\&alpha;}}_{max}-(p-P)\mathrm{\&Delta;}& (P<p\&le;2P)\end{array}\right.---\left(2\right)$

Wherein,

${\mathrm{\&theta;}}_m=\left\{\begin{array}{cc}{\mathrm{\&theta;}}_{\min }+\mathrm{\&omega;}t& (0\&le;t\&le;T_s/2)\\ {\mathrm{\&theta;}}_{\max }-\mathrm{\&omega;}(t-T_s/2)& (T_s/2<t\&le;T_s)\end{array}\right.---\left(3\right)$

Wherein β is electromagnetic wave free-space propagation constant, and d is adjacent array element distance, θ_mFor array radiation patterns wave beam Pointing to, p is phase shifter phase place change frequency, (θ_min, θ_max) it is phase-array scanning scope, ω is phase-array scanning speed, and t is to sweep Retouch time variable, T_s=2 π/ω is the uniform speed scanning phase-array scanning cycle.

5) step 1), 3) in parameter be brought into step 4) expression formula (2), (3), it can be deduced that in the scan period Time series t={t that excitation phase change is corresponding every time₁, t₂..., t_p, t_P+1..., t_2P-1, t_2P}；

6) by step 5) gained time series t is divided by clock signal of system cycle T_CLK, can quantify to obtain a scanning week The arcsine clock sequence that the change of phase underexcitation phase place is corresponding

Count={count₁, count₂..., count_P, count_P+1..., count_2P-1, count_2P}；

7), in the scan period, the numerical value of control system impulse scaler is equal to step 6) in number in arcsine sequence Value, then uniformly change excitation phase phase-shift phase in the corresponding moment, make phased array main lobe beam position within a scan period Uniform speed scanning, finally realizes the uniform speed scanning of phased array.

Step 1) described phased array can be uniform linear array, i.e. each array element be individual antenna unit, it is also possible to Being a uniform planar array, the most each array element can be a submatrix.

Step 3) in, described phase shifter stepping accuracy depends on phase shifter phase quantization figure place, increases quantization digit, carries The scanning accuracy of high array antenna, and described scan period underexcitation phase place change frequency is 2P.

Step 6) in, it is that arcsine rule becomes that described time series and arcsine clock sequence are with phase place change frequency The discrete series changed, and period of change is 2P.

Described time series, arcsine clock sequence and beam main lobe orientation angle are linear relationships.

Seeing Fig. 1, the design procedure of the embodiment of the present invention is as follows:

Step 1: according to phase-array scanning property requirements select sweep limits, scanning speed, phase shifter stepping accuracy and Array antenna basic parameter；

The present embodiment select uniform linear array as shown in Figure 2 (the most each array element can be individual antenna unit also Can be a submatrix), array element number N=60, array element distance is d=λ/2, and λ is electromagnetic wave free space wavelength, phased array system The sweep limits of system is set to (θ_min, θ_max), wherein θ_min=-60 °, θ_max=60 °, scanning speed is ω=100 °/s, and phase place Quantization digit is 6, i.e. phase shifter stepping accuracy Δ=360 °/2⁶。

Step 2: according to array antenna array factor maximum condition, obtain excitation phase difference range between adjacent array element；

Beam position sweep limits in step 1 is brought into array maximum conditional expression, this enforcement can be obtained Excitation phase excursion (α in example_min, α_max), wherein α_min=-155.88 °, α_max=155.88 °.

Step 3: utilize excitation phase difference range and phase shifter stepping accuracy and expression formula (1), obtained for 1/2 scanning week Phase underexcitation phase place maximum changes number of times P=22.

Step 4: revise array antenna array factor maximum condition, obtain phased array array factor maximum expression formula, such as table Reach shown in formula (2), (3).

Step 5: step 1, parameter in 2,3 are brought into step 4) expression formula (2), (3), it can be deduced that a scanning week Time series t that in phase, the change of each excitation phase is corresponding.

In the present embodiment t be with phase place change frequency be arcsine rule change discrete series, element number is 2P= 44, as shown in Figure 4.

Step 6: by step 5 gained time series t divided by clock signal of system cycle T_CLK, can quantify to obtain one and sweep Retouch the arcsine clock sequence count that the change of cycle underexcitation phase place is corresponding；Wherein the present embodiment control system clock cycle T_CLK =0.1 μ s.

Step 7: in the scan period, the numerical value of control system impulse scaler is equal to step 6) in arcsine sequence Numerical value, then uniformly change excitation phase phase-shift phase in the corresponding moment, make phased array main lobe wave beam within a scan period Point to uniform speed scanning, finally realize the uniform speed scanning of phased array.

It can be seen that main lobe beam position is linear with the time from expression formula (3) and Fig. 5, i.e. the method meets The requirement of phased array antenna uniform speed scanning.The present invention is the realization side of a kind of phased array uniform speed scanning based on arcsine clock Method, can be arcsine rule with change frequency by excitation phase transformation period, it is achieved scanning angle was linearly closed with the time The at the uniform velocity phased array of system, whole process has only to control system and selects the suitable time, and equivalent changes excitation phase, contributes to reality The phased array antenna uniform speed scanning control that in existing high scanning accuracy, feeding network, the sequential operation amount of phase shifter control system is less System, simplifies the design complexities of hardware circuit.The highest using value is had in communications fields such as radar, microwave landings.

Claims (1)

1. the implementation method of a phased array uniform speed scanning based on arcsine clock, it is characterised in that comprise the steps:

1) sweep limits, scanning speed, phase shifter stepping accuracy and array antenna are selected according to phase-array scanning property requirements Parameter；

2) according to array antenna array factor maximum condition, excitation phase difference range between adjacent array element is obtained；

3) utilize excitation phase difference range and phase shifter stepping accuracy, obtain 1/2 scan period underexcitation phase place maximum and change Number of timesWherein, (α_min, α_max) it is adjacent array element phase range in battle array, Δ=2 pi/2^kFor moving Phase device stepping accuracy,It is to round up；

4) revise array antenna array factor maximum condition, obtain phased array array factor maximum expression formula:

$\left\{\begin{array}{cc}\mathrm{\&beta;}dsin\left({\mathrm{\&theta;}}_m\right)={\mathrm{\&alpha;}}_{min}+p\mathrm{\&Delta;}& (0\&le;p\&le;P)\\ \mathrm{\&beta;}dsin\left({\mathrm{\&theta;}}_m\right)={\mathrm{\&alpha;}}_{max}-(p-P)\mathrm{\&Delta;}& (P<p\&le;2P)\end{array}\right.$

Wherein,

${\mathrm{\&theta;}}_m=\left\{\begin{array}{cc}{\mathrm{\&theta;}}_{\min }+\mathrm{\&omega;}t& (0\&le;t\&le;T_s/2)\\ {\mathrm{\&theta;}}_{\max }-\mathrm{\&omega;}(t-T_s/2)& (T_s/2<t\&le;T_s)\end{array}\right.$

Wherein β is electromagnetic wave free-space propagation constant, and d is adjacent array element distance, θ_mFor array radiation patterns beam position, p For phase shifter phase place change frequency, (θ_min, θ_max) it is phase-array scanning scope, ω is phase-array scanning speed, and t is sweep time Variable, T_s=2 π/ω is the uniform speed scanning phase-array scanning cycle；

5) by step 1), 3) in parameter be brought into step 4) phased array array factor maximum expression formula, draw a scanning Time series t={t that in cycle, the change of each excitation phase is corresponding₁, t₂..., t_p, t_p+1..., t_2p-1, t_2p}；

6) by time series t divided by clock signal of system cycle T_CLK, obtain a scan period underexcitation phase place change correspondence Arcsine clock sequence

Count={count₁, count₂..., count_p, count_p+1..., count_2p-1, count_2p}；

7) in the scan period, whenever the numerical value of control system impulse scaler is equal to step 6) in certain in arcsine sequence During one numerical value, uniformly change excitation phase phase-shift phase, make phased array main lobe beam position within a scan period at the uniform velocity sweep Retouch, finally realize the uniform speed scanning of phased array.