CN105826659A - Vehicle-mounted ultra-wideband discrete loaded semi-elliptical antenna - Google Patents

Abstract

The invention discloses a vehicle-mounted ultra-wideband discrete loaded semi-elliptical antenna. A transmitting antenna unit and a receiving antenna unit are each composed of two identical semi-elliptical antenna arms. The semi-elliptical antenna arms are correspondingly installed in a paired parallel manner in a reflection cavity which is equally divided by a baffle. The two semi-elliptical antenna arms in the same column are symmetrically printed on the front of an insulated dielectric plate to form a set of ultra-wideband dipole antennas. The two semi-elliptical antenna arms adjacent to the gap are each provided with an input port as a feeding end. Multiple slits are uniformly distributed on the semi-elliptical antenna arms along the major semi-axis direction. Multiple discrete loading resistors are uniformly welded into each slit. The two ends of the bottom side of each semi-elliptical antenna arm are each connected with a metal band through a connecting resistor. The open side of the refection cavity and the edge of the insulated dielectric plate are fixed by nuts. The vehicle-mounted ultra-wideband discrete loaded semi-elliptical antenna has the advantages of large work bandwidth, good time-domain radiation characteristic, compact structure, low height of the reflection cavity, and easy radar miniaturization, and can satisfy the engineering requirements of a vehicle-mounted ultra-wideband detection radar system.

Description

Vehicle-mounted ultra broadband discrete type loads semiellipse antenna

Technical field

The invention belongs to ultra-wideband antenna technical field, be specifically related to a kind of vehicle-mounted ultra broadband discrete type and load semiellipse antenna.

Background technology

Antenna, as radiation and the parts of reception electromagnetic wave, is requisite key component in radar system, and it directly affects the detection resolution of radar system, positioning precision and target recognition ability.Antenna is not had to be impossible to set up any radar system.In general, ultra broadband detection radar antenna system should be directly placed on ground or be arranged near near the ground, its electromagnetic property is highly susceptible to the impact of environment near the ground, and too high terrain clearance can reduce coupling of antenna and underground medium, increases free space loss.In vehicle-mounted ultra broadband acquisition radar system, antenna is arranged in probe vehicles, could be received by reception antenna owing to needing to penetrate medium for twice through the electromagnetic wave of transmitting aerial radiation, it is limited to the impact of medium scattering interference and decay, antenna detection range is shorter, differentiate rate variance, therefore it is required that antenna has good time domain fidelity, ultra-wide band characteristic, high-gain and small size lightweight, and to reduce the antenna pattern impact on probe vehicles as far as possible.

At present, the antenna form that ultra broadband detection radar is conventional mainly has TEM electromagnetic horn, Vivaldi antenna and dipole antenna.For GPR and through-wall radar isopulse detection radar, in order to well with medium couples, obtain more preferable Effect on Detecting, in the course of the work, require that antenna is close proximity to ground or body of wall, therefore the horn antenna that TEM electromagnetic horn and Vivaldi antenna etc. are conventional is not appropriate for applying in this type of radar system, and TEM electromagnetic horn and Vivaldi antenna size are the biggest, it is unfavorable for the integrated, so the antenna with plane dipole form is more reasonably to select to vehicle-mounted ultra wideband radar system of vehicle-mounted and system.

Summary of the invention

Present invention solves the technical problem that there is provided a kind of bandwidth, Time Domain Radiation Characteristics is good, gain is high and easy-to-install vehicle-mounted ultra broadband discrete type loads semiellipse antenna.

nullThe present invention solves that above-mentioned technical problem adopts the following technical scheme that，Vehicle-mounted ultra broadband discrete type loads semiellipse antenna，It is characterized in that including transmission antenna unit、Reception antenna unit、Insulation medium board、Reflection cavity、Discrete type loading resistor、Metal tape and connection resistance，Wherein transmission antenna unit and reception antenna unit are made up of two identical semiellipse antenna arms respectively，Semiellipse antenna arm correspondence arranged side by side two-by-two is installed in the reflection cavity separated by baffle plate average mark，The front that two semiellipse antenna arms of same column are printed on insulation medium board symmetrically constitutes one group of ultra wide band dipolar antenna，The major semiaxis direction of two semiellipse antenna arms of same column and baffle plate is parallel and is provided with interval between two semiellipse antenna arms of same column，It is respectively equipped with input port as respective feed end on two semiellipse antenna arms of adjacent partition，It is evenly equipped with a plurality of gap along major semiaxis direction on semiellipse antenna arm，In every gap, uniform welding has multiple discrete type loading resistor，The two ends, bottom side of semiellipse antenna arm connect and compose loading loop by connection resistance and metal tape respectively，Reflection cavity is the rectangular metal cavity with an opening surface，The opening surface of this reflection cavity is fixed by nut with the edge of insulation medium board.

Further preferably, a length of 166mm of major semiaxis of described semiellipse antenna arm, minor axis length is 120mm, and in every gap of semiellipse antenna arm, total resistance of discrete type loading resistor draws according to Wu-king loading computing formula, specific as follows:

$\begin{array}{cc}{R}_i=\frac{60\mathrm{\ψ}\left(z_i\right)}{L-\left|z_i\right|}& \left(\mathrm{\Ω}/m\right)\end{array}$

$\mathrm{\ψ}\left(z_i\right)=\frac{{\∫}_0^L\left(L-z^{\′}\right)e^{-{\mathrm{jk}}_0{z}^{\′}}\left(e^{-{\mathrm{jk}}_0{D}_1}/D_1+e^{-{\mathrm{jk}}_0{D}_2}/D_2\right){\mathrm{dz}}^{\′}}{\left(L-\left|z_i\right|\right)e^{-{\mathrm{jk}}_0\left|z_i\right|}}$

$D_1={\[{(z_i+z^{\′})}^2+a^2\]}^{\frac{1}{2}}$

$D_2={\[{(z_i-z^{\′})}^2+a^2\]}^{\frac{1}{2}}$

Wherein R_iBeing the total resistance of the loading resistor in i-th gap, L is the major semiaxis length of semiellipse antenna arm, z_iFor the vertical dimension of semiellipse antenna arm feed end Yu gap, discrete type loading resistor place, k₀For free space wave number, a is the radius of flagpole antenna, Wu-king loads and is mainly used in flagpole antenna, therefore in calculation design, twice equivalent transformation has been done based on area is identical, first under major semiaxis same case, semiellipse dipole antenna is equivalent to a rectangle, is then shaft-like by rectangular equivalent under conditions of lateral area is equal.

Further preferably, described semiellipse antenna arm is evenly equipped with 6 gaps along major semiaxis direction, by resistance R soldering surface mounted on these gaps_iRealize loading, through calculating and optimizing and consider actual resistance distribution situation, loading resistor R in described every gap_iIt is made up of the parallel resistance of 5 uniform weldings, start the resistance of discrete type loading resistor in gap from the feed end of semiellipse antenna arm and be followed successively by 50 Ω, 60 Ω, 75 Ω, 100 Ω, 130 Ω and 220 Ω, between two semiellipse antenna arms of same column spaced apart for 4mm, the resistance connecting resistance is 300 Ω.

Further preferably, described insulation medium board is the epoxy resin fiberglass cloth dielectric-slab that one side covers copper, and its dielectric constant is 4.4, a length of 336mm, and width is 300mm, and thickness is 0.5-2mm.

Further preferably, described reflection cavity is aluminum rectangular cavities, and its height is 1/25, a length of 360mm of free space wavelength corresponding to center of antenna frequency, and width is 300mm.

The present invention is installed on bottom probe vehicles, has that work strip is roomy, Time Domain Radiation Characteristics good, compact conformation, antenna-reflected chamber height are low and is prone to the feature of Radar Miniaturization, it is possible to meet the engineering demand of vehicle-mounted ultra broadband acquisition radar system.

Accompanying drawing explanation

Fig. 1 is the structural representation of the present invention；

Fig. 2 is the input impedance curve of the present invention；

Fig. 3 is the isolation curve of the present invention；

Fig. 4 is 1m position time-domain radiation wavy curve immediately below the present invention.

In figure: 1, transmission antenna unit, 2, reception antenna unit, 3, insulation medium board, 4, reflection cavity, 5, discrete type loading resistor, 6, metal tape, 7, connect resistance.

Detailed description of the invention

The particular content of the present invention is described in detail in conjunction with accompanying drawing.nullAs shown in Figure 1，Vehicle-mounted ultra broadband discrete type loads semiellipse antenna，Including transmission antenna unit 1、Reception antenna unit 2、Insulation medium board 3、Reflection cavity 4、Discrete type loading resistor 5、Metal tape 6 and connection resistance 7，Wherein transmission antenna unit 1 and reception antenna unit 2 are made up of two identical semiellipse antenna arms respectively，Semiellipse antenna arm correspondence arranged side by side two-by-two is installed in the reflection cavity 4 separated by baffle plate average mark，The front that two semiellipse antenna arms of same column are printed on insulation medium board 3 symmetrically constitutes one group of ultra wide band dipolar antenna，The major semiaxis direction of two semiellipse antenna arms of same column and baffle plate is parallel and is provided with interval between two semiellipse antenna arms of same column，It is respectively equipped with input port as respective feed end on two semiellipse antenna arms of adjacent partition，It is evenly equipped with a plurality of gap along major semiaxis direction on semiellipse antenna arm，In every gap, uniform welding has multiple discrete type loading resistor 5，The current reflection of antenna end can be effectively reduced，Suppressor pulse trails，The two ends, bottom side of semiellipse antenna arm connect and compose loading loop by connection resistance 7 and metal tape 6 respectively，Reflection cavity 4 is the rectangular metal cavity with an opening surface，The edge of the opening surface of this reflection cavity 4 and insulation medium board 3 is fixed by nut.

The a length of 166mm of major semiaxis of described semiellipse antenna arm, minor axis length is 120mm, and in every gap of semiellipse antenna arm, total resistance of discrete type loading resistor 5 draws according to Wu-king loading computing formula, specific as follows:

$\begin{array}{cc}{R}_i=\frac{60\mathrm{\ψ}\left(z_i\right)}{L-\left|z_i\right|}& \left(\mathrm{\Ω}/m\right)\end{array}$

$\mathrm{\ψ}\left(z_i\right)=\frac{{\∫}_0^L\left(L-z^{\′}\right)e^{-{\mathrm{jk}}_0{z}^{\′}}\left(e^{-{\mathrm{jk}}_0{D}_1}/D_1+e^{-{\mathrm{jk}}_0{D}_2}/D_2\right){\mathrm{dz}}^{\′}}{\left(L-\left|z_i\right|\right)e^{-{\mathrm{jk}}_0\left|z_i\right|}}$

$D_1={\[{(z_i+z^{\′})}^2+a^2\]}^{\frac{1}{2}}$

$D_2={\[{(z_i-z^{\′})}^2+a^2\]}^{\frac{1}{2}}$

Wherein R_iBeing the total resistance of the loading resistor in i-th gap, L is the major semiaxis length of semiellipse antenna arm, z_iFor the vertical dimension of semiellipse antenna arm feed end Yu gap, discrete type loading resistor 5 place, k₀For free space wave number, a is the radius of flagpole antenna.Wu-king loads and is mainly used in flagpole antenna, therefore in calculation design, twice equivalent transformation has been done based on area is identical, first under major semiaxis same case, semiellipse dipole antenna is equivalent to a rectangle, is then shaft-like by rectangular equivalent under conditions of lateral area is equal.

6 gaps it are evenly equipped with along major semiaxis direction, by resistance R soldering surface mounted on these gaps on described semiellipse antenna arm_iRealize loading.Through calculating and optimizing and consider actual resistance distribution situation, loading resistor R in described every gap_iIt is made up of the parallel resistance 5 of 5 uniform weldings, start the resistance of discrete type loading resistor 5 in gap from the feed end of semiellipse antenna arm and be followed successively by 50 Ω, 60 Ω, 75 Ω, 100 Ω, 130 Ω and 220 Ω, between two semiellipse antenna arms of same column spaced apart for 4mm, can be adjusted spaced apart between two semiellipse antenna arms according to antenna technology index requests such as input impedances, the resistance connecting resistance 7 is 300 Ω.

Described insulation medium board 3 covers the epoxy resin fiberglass cloth dielectric-slab of copper for one side, and its dielectric constant is 4.4, a length of 336mm, and width is 300mm, and thickness is 0.5-2mm.

Described reflection cavity 4 is aluminum rectangular cavities, according to simulation optimization design result, restriction and the requirement of Time Domain Radiation Characteristics in view of antenna installation environment, this reflection cavity 4 uses short back of the body chamber to design, its height is the 1/25 of free space wavelength corresponding to center of antenna frequency, a length of 360mm, width is 300mm.

As in figure 2 it is shown, be the input impedance curve of vehicle-mounted ultra broadband discrete type loading semiellipse antenna, in frequency range, can be seen that the input impedance curve ratio of antenna is flatter, real part is maintained at about 100 Ω, and imaginary values is less simultaneously, shows that antenna port reflection is the least.

As it is shown on figure 3, be the vehicle-mounted ultra broadband discrete type isolation curve that loads between semiellipse antenna, as can be seen from the figure in 250-750MHz frequency band range isolation all not less than 35dB.

As shown in Figure 4, loading 1m position time-domain radiation wavy curve immediately below semiellipse antenna for vehicle-mounted ultra broadband discrete type, now antenna is arranged on bottom probe vehicles, in figure, abscissa representation unit is the time variable of ns, and vertical coordinate is normalized pulses of radiation amplitude.It can be seen that when antenna is arranged on bottom probe vehicles, the vibration hangover of its radiation waveform is the least, and oscillation level is less than 10%, shows that this antenna has good Time Domain Radiation Characteristics.

In sum, the vehicle-mounted ultra broadband discrete type that the present invention provides loads semiellipse antenna and is installed on bottom probe vehicles, there is the features such as the miniaturization that work strip is roomy, Time Domain Radiation Characteristics good, compact conformation, antenna-reflected chamber height are low and is prone to radar, it is possible to meet the engineering demand of vehicle-mounted ultra broadband acquisition radar system.

The ultimate principle of the present invention, principal character and advantage have more than been shown and described, and without departing from the spirit and scope of the present invention, the present invention also has various changes and modifications, and these changes and improvements both fall within the scope of claimed invention.

Claims (5)

1. nullThe most vehicle-mounted ultra broadband discrete type loads semiellipse antenna，It is characterized in that including transmission antenna unit、Reception antenna unit、Insulation medium board、Reflection cavity、Discrete type loading resistor、Metal tape and connection resistance，Wherein transmission antenna unit and reception antenna unit are made up of two identical semiellipse antenna arms respectively，Semiellipse antenna arm correspondence arranged side by side two-by-two is installed in the reflection cavity separated by baffle plate average mark，The front that two semiellipse antenna arms of same column are printed on insulation medium board symmetrically constitutes one group of ultra wide band dipolar antenna，The major semiaxis direction of two semiellipse antenna arms of same column and baffle plate is parallel and is provided with interval between two semiellipse antenna arms of same column，It is respectively equipped with input port as respective feed end on two semiellipse antenna arms of adjacent partition，It is evenly equipped with a plurality of gap along major semiaxis direction on semiellipse antenna arm，In every gap, uniform welding has multiple discrete type loading resistor，The two ends, bottom side of semiellipse antenna arm connect and compose loading loop by connection resistance and metal tape respectively，Reflection cavity is the rectangular metal cavity with an opening surface，The opening surface of this reflection cavity is fixed by nut with the edge of insulation medium board.
2. Vehicle-mounted ultra broadband discrete type the most according to claim 1 loads semiellipse antenna, it is characterized in that: a length of 166mm of major semiaxis of described semiellipse antenna arm, minor axis length is 120mm, in every gap of semiellipse antenna arm, total resistance of discrete type loading resistor draws according to Wu-king loading computing formula, specific as follows:

   $R_i=\frac{60\mathrm{\ψ}\left(z_i\right)}{L-\left|z_i\right|}(\mathrm{\Ω}/m)$

   $\mathrm{\ψ}\left(z_i\right)=\frac{{\∫}_0^L\left(L-z^{\′}\right)e^{-{\mathrm{jk}}_0{z}^{\′}}\left(e^{-{\mathrm{jk}}_0{D}_1}/D_1+e^{-{\mathrm{jk}}_0{D}_2}/D_2\right){\mathrm{dz}}^{\′}}{\left(L-\left|z_i\right|\right)e^{-{\mathrm{jk}}_0\left|z_i\right|}}$

   $D_1={\[{(z_i+z^{\′})}^2+a^2\]}^{\frac{1}{2}}$

   $D_2={\[{(z_i-z^{\′})}^2+a^2\]}^{\frac{1}{2}}$

   Wherein R_iBeing the total resistance of the loading resistor in i-th gap, L is the major semiaxis length of semiellipse antenna arm, z_iFor the vertical dimension of semiellipse antenna arm feed end Yu gap, discrete type loading resistor place, k₀For free space wave number, a is the radius of flagpole antenna, Wu-king loads and is mainly used in flagpole antenna, therefore in calculation design, twice equivalent transformation has been done based on area is identical, first under major semiaxis same case, semiellipse dipole antenna is equivalent to a rectangle, is then shaft-like by rectangular equivalent under conditions of lateral area is equal.
3. Vehicle-mounted ultra broadband discrete type the most according to claim 1 loads semiellipse antenna, it is characterised in that: it is evenly equipped with 6 gaps on described semiellipse antenna arm along major semiaxis direction, by resistance R soldering surface mounted on these gaps_iRealize loading, through calculating and optimizing and consider actual resistance distribution situation, loading resistor R in described every gap_iIt is made up of the parallel resistance of 5 uniform weldings, start the resistance of discrete type loading resistor in gap from the feed end of semiellipse antenna arm and be followed successively by 50 Ω, 60 Ω, 75 Ω, 100 Ω, 130 Ω and 220 Ω, between two semiellipse antenna arms of same column spaced apart for 4mm, the resistance connecting resistance is 300 Ω.
4. Vehicle-mounted ultra broadband discrete type the most according to claim 1 loads semiellipse antenna, it is characterized in that: described insulation medium board is the epoxy resin fiberglass cloth dielectric-slab that one side covers copper, its dielectric constant is 4.4, a length of 336mm, width is 300mm, and thickness is 0.5-2mm.
5. Vehicle-mounted ultra broadband discrete type the most according to claim 1 loads semiellipse antenna, it is characterised in that: described reflection cavity is aluminum rectangular cavities, and its height is 1/25, a length of 360mm of free space wavelength corresponding to center of antenna frequency, and width is 300mm.