CN109190303A - Middle short range search radar emits signal width pulse width ratio design method - Google Patents

Abstract

The present invention discloses a kind of middle short range search radar transmitting signal width pulse width ratio design method, and this method is for middle short range search radar transmitting signal pulse repetition period, the design of width pulse width.The present invention, which is solved the problems, such as over, finds wide, narrow pulse width by heuristic method, by the derivation to wide, burst pulse detection range, gives width, narrow pulse width ratio and emits signal dutyfactor α, is connected coefficient gamma, σ_{It is small}, σ_GreatlyRelationship, can directly calculate wide, narrow pulse width ratio value range.Compared to conventional heuristic method, the method in the present invention can directly find out optimal wide, narrow pulse width ratio.

Description

Middle short range search radar emits signal width pulse width ratio design method

Technical field

The invention belongs to Radar Technology fields, and in particular to middle short range search radar transmission signal parameters design is applied to Middle short range search radar transmitting signal width pulse width design, consequently facilitating quickly reasonably finding out optimal width pulse width Than.

Background technique

Middle short range search radar in order to solve the contradiction of minimum detectable range and maximum probe power, often select by transmitting signal The pulse signal of wide, narrow two kinds of pulse widths, wide pulse signal are responsible for the detection to far field airspace, and narrow pulse signal is responsible for close The detection in area airspace.The echo-signal of two kinds of pulse widths, which shares, receives the period, and the timing for emitting signal is as shown in Figure 1.

Since broad pulse and burst pulse share reception interval, in order to distinguish the echo of two kinds of pulses, often using different Signal form and signal frequency.After wide, narrow pulse signal, to solve that different RCS targets are wide, burst pulse detection range have A series of problems, such as effect connection problem emits signal pulse repetition period select permeability, and wide, narrow pulse width designs.

It is provided there is presently no pertinent literature and how to select wide, narrow pulse width ratio, correlative technology field is to pass through examination The method of spy provides the design of width pulse width.Heuristic method obtains transmitting signal pulse according to the power of radar first and repeats week Phase and broad pulse width find out narrow pulse width according to minimum detectable range, then calculate width arteries and veins within the scope of detection target RCS Radar power coverage area is rushed, if width pulse detection distance can not be connected, width pulse width is readjusted, so recycles Until finding the width pulse width met the requirements.Heuristic method is computationally intensive, low efficiency, the width arteries and veins met the requirements found It rushes width not optimize, the present invention gives width pulse width ratio value range by the derivation of equation, chooses ratio Optimal width pulse width ratio can be obtained in maximum value.

Summary of the invention

Technical problems to be solved

In order to avoid the shortcomings of the prior art, the present invention proposes a kind of middle short range search radar transmitting signal width arteries and veins It rushes width and compares design method.

Technical solution

A kind of middle short range search radar transmitting signal width pulse width ratio design method, it is characterised in that steps are as follows:

Step 1: according to duty cycle alpha, linking coefficient gamma, radar detection target RCS minimum value σ_{It is small}With maximum value σ_Greatly, calculate The value range of broad pulse and burst pulse time width ratio beta:

Step 2: β takes the maximum value met the requirements, calculates σ_GreatlyCorresponding radar horizon R_{Max_ wide}:

Wherein, P_tFor emission peak power, G_tFor transmitter antenna gain (dBi), G_rFor receiving antenna gain, λ is wavelength, and σ is mesh Specular cross section is marked, k is Boltzmann constant, D₀It (1) is detecting factor, T_sTo receive system equivalent noise temperature, L_sTo be System loss, T are wave beam residence time；

Step 3: according to R_{Max_ wide}Calculate pulse repetition period t:

R_{Max_ wide}≈t(1-α)×150×10⁶

Step 4: it is wide that width pulse being found out by duty cycle alpha, pulse repetition period t, broad pulse and burst pulse time width ratio β value Degree:

Beneficial effect

A kind of middle short range search radar proposed by the present invention emits signal width pulse width ratio design method, and what is had has Beneficial effect is:

1) formula (17) gives width, narrow pulse width ratio and emits signal dutyfactor α, is connected coefficient gamma, σ_{It is small}, σ_Greatly's Relationship can directly calculate wide, narrow pulse width ratio value range；

2) it solves the problems, such as over and wide, narrow pulse width is found by heuristic method；

3) radar emission signal parameter can more reasonably be designed by formula (5), formula (10), formula (17).

Detailed description of the invention

Fig. 1 emits signal timing diagram

Fig. 2 wide, burst pulse investigative range schematic diagram

Specific embodiment

Now in conjunction with embodiment, attached drawing, the invention will be further described:

According to radar equation:

Wherein:

P_t: emission peak power

τ: fire pulse width

G_t: transmitter antenna gain (dBi)

G_r: receiving antenna gain

λ: wavelength

σ: specular cross-section

I_i: accumulation improvement factor

K: Boltzmann constant

T_s: receive system equivalent noise temperature

D₀(1): detecting factor

L_s: system loss

Assuming that:

Broad pulse and burst pulse time width ratio are as follows: β,

Pulse repetition period are as follows: t

Wave beam residence time are as follows: T

Emit signal dutyfactor are as follows: α,

Then:

By formula (2), formula (3) substitutes into formula (1), can obtain:

By formula (2), formula (4) substitutes into formula (1), can obtain:

If:

Then:

As shown in Figure 2, since narrow pulse signal time width is small, maximum detectable range when broad pulse detection range is not fuzzy Are as follows:

R_{Max_ wide}≈t(1-α)×150×10⁶ (10)

Burst pulse distance measurement, which is greater than, is equal to transmitting pulse signal blind area, therefore:

R_{Max_ is narrow}≥tα×150×10⁶ (11)

It is equal to transmitting pulse signal detection since there are directional diagram mismatch loss, burst pulse distance measurement is greater than in practice γ times of blind area, γ are defined as linking coefficient, and the value of γ is determined by system parameters, therefore:

R_{Max_ is narrow}≥tαγ×150×10⁶ (12)

Radar detection object generally comprises the typical targets such as fixed wing aircraft, armed helicopter, unmanned plane, cruise missile, The RCS of target is generally by 0.01m²To 2m²It differs, some radars require the RCS range of detection target wider.Ideal signal shape Formula, may be implemented effective detection to all typical targets, and wide, burst pulse detection range can also be connected well.This method is logical The derivation of equation is crossed, wide, the narrow pulse width ratio value range in the case where setting RCS ambit is given, solves over and pass through Heuristic method finds out wide, narrow pulse width conventional method.

Assuming that the range of radar detection target RCS is σ_{It is small}~σ_GreatlyIf to be met wide, narrow using same group of transmitting signal The linking of pulse detection distance it is necessary to simultaneously meet the following conditions: σ_GreatlyThe detection range of target needs to meet

R_{Max_ wide}≈t(1-α)×150×10⁶, σ_{It is small}The detection range of target need to meet R_{Max_ is narrow}≥tα×150×10⁶, will be public Formula (8) substitutes into formula (10), and formula (9) are substituted into formula (12), therefore:

It can be derived by formula (13):

Formula (15) substitution formula (14) can be derived:

It can be derived by formula (16):

By formula (5) and formula (17) it follows that

Emit under signal dutyfactor α, linking coefficient gamma certain situation, σ_{It is small}It is smaller, σ_GreatlyBigger, β is smaller, R_{Max_ wide}It is smaller.Cause This, the range of radar detection target RCS is bigger, and the detection range of big target is closer, this is often that we are undesirable；β is got over Greatly, R_{Max_ wide}Bigger, β takes the maximum value met the requirements.

This method gives middle short range search radar by the derivation of equation and emits wide signal, narrow pulse width ratio and transmitting Signal dutyfactor α, linking coefficient gamma, σ_{It is small}, σ_GreatlyRelationship, can directly calculate wide, narrow pulse width ratio value range.It can Emit signal pulse repetition period, width pulse width to rationally design.Specific implementation step is as follows:

1) radar emission signal dutyfactor, linking coefficient and detection target RCS range are determined, that is, determines duty cycle alpha, rank Meet coefficient gamma, σ_{It is small}And σ_Greatly；

2) according to the above parameter, β value range is calculated by formula (17)；

3) β takes the maximum value met the requirements, calculates σ according to formula (5)_GreatlyCorresponding radar horizon R_{Max_ wide}；

4) pulse repetition period t can be found out according to formula (10)；

5) according to formula (3), (4) by duty cycle alpha, pulse repetition period t, β value finds out width pulse width.

Claims (1)

1. a kind of middle short range search radar emits signal width pulse width ratio design method, it is characterised in that steps are as follows:

Step 1: according to duty cycle alpha, linking coefficient gamma, radar detection target RCS minimum value σ_{It is small}With maximum value σ_Greatly, calculate wide arteries and veins The value range of punching and burst pulse time width ratio beta:

Step 2: β takes the maximum value met the requirements, calculates σ_GreatlyCorresponding radar horizon R_{Max_ wide}:

Wherein, P_tFor emission peak power, G_tFor transmitter antenna gain (dBi), G_rFor receiving antenna gain, λ is wavelength, and σ has for target Reflective surface area is imitated, k is Boltzmann constant, D₀It (1) is detecting factor, T_sTo receive system equivalent noise temperature, L_sFor system damage Consumption, T are wave beam residence time；

Step 3: according to R_{Max_ wide}Calculate pulse repetition period t:

R_{Max_ wide}≈t(1-α)×150×10⁶

Step 4: width pulse width is found out by duty cycle alpha, pulse repetition period t, broad pulse and burst pulse time width ratio β value: