CN1068912A

CN1068912A - Improved the decameter-wave antenna of wind resistance

Info

Publication number: CN1068912A
Application number: CN 92105632
Authority: CN
Inventors: 法兰科斯·乌森巴赫; 法兰科斯·莱芬
Original assignee: Thomson CSF SA
Current assignee: Thales SA
Priority date: 1991-07-19
Filing date: 1992-07-18
Publication date: 1993-02-10
Also published as: YU71092A; JPH05226933A; CZ220492A3; DE69205906T2; FR2679383B1; FR2679383A1; EP0524045B1; DE69205906D1; EP0524045A1

Abstract

Disclosed content relates to decameter-wave antenna, and this antenna comprises a vertical dipole screen at least, and these dipole groupings are arranged on the different horizontal line.Changed the rectangular shape of the dipole screen of existing antenna, be less than the dipole number of lower, made the top of screen narrow down by the dipole number that makes the position higher position.The reflector relevant with screen also correspondingly obtained the top surface configuration narrower than the bottom.Though therefore the radiation characteristic of antenna has decline, antenna structure greatly to alleviate also slightly thereby has much bigger wind resistance.Disclosed device designs in particular for rotable antenna.

Description

Improved the decameter-wave antenna of wind resistance

The present invention relates to the wind resistance problem of especially this antenna of decameter wave dipole array antenna.Though this problem is not limited only to the Rotation screen antenna, however very outstanding concerning this kind antenna.This just below will be at the reason of this antenna research wind resistance problem and solution.This paper also will narrate this solution and in fact be arranged in same plane for fixed antenna as the dipole in arranging between the fixed vertical mast, and this just means and is not referred to as dipole submatrix or dipole screen with can making any distinction between.

The decameter wave array antenna of dipoles is that a kind of height and width all reach tens of meters antenna, height that has and width even reach more than 100 meters.Existing antenna is made up of the rectangle orthogonal array that dipole forms, and these dipoles are distributed on additional horizontal stroke, the ordinate symmetrically, and antenna dipole array is rectangle or square always often.This an array always is in the same place with a reflector, and this reflector is made of parallel wire usually, and this reflector itself also is a rectangle or square, and its size is more much bigger again than dipole submatrix, and this reflector is parallel to the dipole submatrix.After the size of given decameter-wave antenna, it is very difficult making a firm antenna, thereby also is very expensive.And if can not guarantee its robustness, consequently when high wind is arranged, the adaptability of antenna will change greatly.This change will cause its radiation characteristic disturbed and even can not work fully.

The objective of the invention is to prevent or alleviate above-mentioned defective at least.

The method of specific implementation is to make the distribution of the dipole on the screen be different from prior art, promptly adopts a kind of rectangle or square shape of being different from.

The decameter-wave antenna that the present invention relates to is made of a vertical reflector and a vertical screen, and they all are operated on the given frequency range, and this screen is distributed in the individual not radiation dipole of coplanar of n by the n group and constitutes, and n is one and is not less than 2 integer.At least lack one at top one group dipole number than the dipole number of one group of lowermost layer, between any two dipole groups, than the number in no more than Yu the lower group of the dipole number in higher a group.

The accompanying drawing summary

Can better understand the present invention and characteristics by following description and relevant accompanying drawing, wherein:

Fig. 1 and Fig. 2 represent facing and end view of existing antenna respectively;

Fig. 3 and Fig. 4 represent the front view of two kinds of antennas the present invention relates to respectively.

In different accompanying drawings, identical reference symbol is represented corresponding element.

Illustrated in figures 1 and 2 is a decameter wave dual rotary antenna, and it highly is 82 meters, and width is 76 meters, is made up of support section and two antennas; Low-frequency antenna is operated in the 6-11MHz frequency range, and high frequency antenna works in the 11-26MHz frequency range.

Support section comprises the hollow pedestal L of the brick one-tenth of usefulness, and the room in the pedestal is used to place transmitter and mechanical part, and mechanical part comprises a driving shaft, is used to drive the annulus C rotation on the roof.The lower end of the same vertical mobile jib M of this annulus is fixed together, and is fixed with four crossbeam P1 on this bar to P4, and these four crossbeams all are positioned on the same vertical plane.One end of 40 cross bars (as b1 to b4 and B1 to B6) is fixed on a certain crossbeam.Rigid rod is used for support (as T1 and T2) or support bar such as T3, and they are fixed on the end of crossbeam P1 to P4, and in fact they be arranged in same plane with crossbeam.Two support bars (as T3) make crossbeam P2 support P1.Drag-line such as H1 hang bolt with H2 on vertical mobile jib with crossbeam.This root bar comprises three parts: the vertical mobile jib M1 of the tubular of circular cross-section, the screen work part M2 of vertical beam is housed, and two bars are welded together to form the part M3 of acute angle shape upwards.

Low-frequency antenna is a HR4/4/0.5 type antenna, and it has a horizontal dipole screen H and a reflector R, and four folding half-wave dipoles are all arranged on each row and column on the screen, and the first row oscillator equals half of the average operation wavelength of antenna apart from the height on ground.Therefore, the dipole screen of low-frequency antenna is made of to d16 16 dipole d1, and they are fixed on 16 the free end in 40 cross bars, as b1 to b4.These dipoles all are arranged in same vertical plane, and this face is parallel to the vertical plane of crossbeam P1 to the P4 place.Must be pointed out that in Fig. 1 and Fig. 3,4, different dipoles is represented the part of its rigidity with thick line on front view, represent its conductor part with thin parallel lines.To between d16 vertical plane and the crossbeam vertical plane, perhaps or rather, on the plane of crossbeam front end, parallel with preceding two vertical planes the 3rd vertical plane that is formed by horizontal wire, i.e. the reflector Rb of low-frequency antenna are arranged at dipole d1.Horizontal wire on the reflector is supported that by an edge cable C1 this root cable is by the top of vertical mobile jib M and the free end of support (as T1 and T2).Interval between the horizontal wire of reflector Rb is kept by vertical cable (as K1), and each horizontal wire all is fixed thereon according to certain intervals.In Fig. 1, can see the high frequency antenna of reflector back in order to make the reader, so low-frequency antenna reflector (Rb) is not drawn fully.In Fig. 2, this reflector is represented its profile on plane in the drawings with an intermittent line.

High frequency antenna is a HR4/6/0.75 type antenna, and it has a horizontal dipole screen H, a reflector R, and every row has four folding half-wave dipoles, whenever shows six on the screen, and the first row dipole is 0.75 times of the average operation wavelength of this antenna apart from the height on ground.Therefore, the dipole screen of high frequency antenna is made up of to D24 24 dipole D1, and they are fixed on 24 the free end in 40 cross bars, (for example B1 is to B6).These dipoles are positioned on the same vertical plane, and this face is parallel to the vertical plane of crossbeam P1 to the P4 place.The reflector Rh of high frequency antenna is made of the lead vertical plane of level, and this face is positioned at crossbeam P1 to the rear end face of P4, is between the dipole screen of reflector Rb and high frequency antenna; The horizontal wire of reflector Rh is by the framework support, this framework is by entablature P1, edge cable (as C2) constitutes, its lower end is that an end is fixed on two supports (as T4) on the sill P4, distance between the horizontal wire of reflector Rh is kept by vertical cable (as K2), and horizontal wire all is fixed thereon according to certain intervals.Rb is the same with reflector, and reflector Rh is not drawn in Fig. 1 fully yet, so that the reader can see the high frequency antenna dipole screen that is positioned at its back, represents its profile on the diagram plane with an intermittent line in Fig. 2.

According to Fig. 1 and Fig. 2, because the physical dimension of this kind antenna, also because those constitute the surface of two dipole screens and two reflectors, wind will produce serious stress on this antenna structure.This stress will be passed earthward.The dynamic pressure that wind causes that is to say that with highly increasing the main stress that wind causes appears at the top of this kind antenna structure, and this is because top is the longest far from the ground arm of force.In addition, the existence on antenna top has strengthened the cycle of oscillation of this structure.Cycle is longer, and the effect degree of the dynamic effect of wind just increases the more.This just inspires us to produce the idea of revising the top of Figure 1 and Figure 2 antenna.

Fig. 3 and Fig. 4 have provided the example of two new antennas that obtain by the top of revising the Figure 1 and Figure 2 antenna.In fact this modification has reduced the cost of antenna, because vertical mobile jib M and hollow base L no longer need to bear the stress resembling in the past, their cost is also just than reduced in the past.

Antenna shown in Figure 3 is corresponding with the antenna of Figure 1 and Figure 2, and wherein the dipole d1 and the d4 of low-frequency antenna have been cancelled, so:

The length of-entablature P1 has been reduced about 2/3rds;

-two support bars (as T3) by two braces (as J) replacement, the latter leans against on the vertical mobile jib and supporting traverse P1;

The surface area of-low-frequency antenna reflector Rb is owing to deduct angle two on and greatly reduce, and the lead of this reflector is still as former mode but be fixed on the end of crossbeam P1 and P2 by new support (as T5, T6);

The surface area of-high frequency antenna reflector Rh also slightly reduces.This is because its fixed system has had change: because the length of crossbeam P1 reduces, edge cable (as C2) upwards stretches.

Antenna shown in comparison diagram 3 and Fig. 1,2 draws following result:

The performance characteristic of-high frequency antenna does not change;

The gain of-low-frequency antenna about 0.5dB that descended;

About 0.8 degree has been improved at the elevation angle of-low-frequency antenna wave beam, and this influence can reduce by presenting higher power to the top dipole;

The weight of the antenna part that-hollow base L is above reduces 15% approximately.

Antenna shown in Figure 4 is corresponding with the antenna shown in Fig. 1 and 2, and wherein dipole D1, D4, D5, the D8 of dipole d1, d4, d5, d8 and the high frequency antenna of low-frequency antenna have been cancelled.So nearly 2/3rds with regard to making that the length of crossbeam P1 and P2 has reduced, go up the surface area minimizing that angles make reflector Rb and Rh owing to cancelled two simultaneously.It is to be noted that compare with the antenna of Fig. 3, the change of this antenna is much bigger.

Comparison diagram 4 and Fig. 1,2 antenna draw following result:

The gain video frequency of-low-frequency antenna has descended about 1 to 1.5dB, and 1 to 1.5 degree has been raised at the elevation angle;

The gain video frequency of-high frequency antenna has descended 0.8 to 1dB, and 1 degree has been raised at the elevation angle;

Be noted that the variation that can reduce the wave beam elevation angle, that is to say those dipoles of comparing with minimum row on those row that contain less dipole number are presented more power by the method for the dipole of high-level position being presented more power.

The present invention is not limited to described example.That it can be applied to fix very at large or rotate decameter-wave antenna, this antenna comprises a dipole vertical screen at least, these dipole groupings are arranged on the different horizontal line, be less than the dipole number of floor level on capable at the dipole number on the highest horizontal line, between any two horizontal line, the dipole number on the higher level row equates with dipole number on reduced levels is capable at the most.In addition, the dipole number in some group may be odd number and in other groups for even number.In this case, depart from dipole position in the odd number group for the symmetry that keeps screen can make dipole position in the even number set, promptly the dipole between varying level is capable is no longer pressed column alignment.Certainly it is not necessary doing like this.

Though the present invention is being that example is described with folding half-wave dipole, it also goes for the dipole of other type, such as full-wave dipole.

Claims

1, a kind of decameter-wave antenna that improves wind resistance, comprise a vertical reflector and a vertical screen that is operated in given frequency range, this vertical screen is formed by the radiation dipole, these dipoles are divided into several groups and are arranged on n the different horizontal line, n is not less than 2 integer, compare with the dipole number on the minimum row at the dipole number on the highest level row and will lack one at least, between any two groups of dipoles, the dipole number in high one group of horizontal level is not more than the dipole number in low one group of horizontal level.

2, according to a kind of decameter-wave antenna that improves wind resistance of claim 1, comprise a rotatable vertical mobile jib, reflector all is fixed on this vertical mobile jib with screen.

3, according to a kind of decameter-wave antenna that improves wind resistance of claim 2, comprise another vertical screen that forms by dipole, this vertical screen is parallel to reflector, for the aforementioned vertical screen that works in given frequency range, this vertical screen is positioned at the other one side of reflector, and this vertical screen also is fixed on the vertical mobile jib and works in than on the higher frequency range of aforementioned given frequency range.

4, according to a kind of decameter-wave antenna that improves wind resistance of claim 3, wherein another screen is a rectangular screen, and its overall size is less than the aforementioned vertical screen that works in given frequency range.

5, according to a kind of decameter-wave antenna that improves wind resistance of claim 3, wherein the grouping of the dipole on another screen is arranged on m the different horizontal line, and m is not less than 2 integer.Wherein the dipole number on the highest level row is compared with the dipole number on floor level is capable and will be lacked one at least.Between any two groups of dipoles, the dipole number in higher one group of horizontal level is not more than the dipole number in lower one group of horizontal level.

6, according to a kind of decameter-wave antenna that improves wind resistance of claim 1, wherein the power of each dipole distributes in the following manner: containing between two groups of dipoles of different numbers, that less group dipole of number is accepted bigger power.