RU2672503C1 - Ultra broadband antenna range dmv2 - Google Patents

Abstract

FIELD: radio engineering and communications.

SUBSTANCE: invention relates to radio engineering, namely to broadband antennas of transceiver devices. Device contains two dipoles. Each of the dipoles is made of two radiating elements installed with a gap between them, which are electrically connected via a feeder line. Each of the radiating elements of the dipole is made in the form of the lower glass – inverted, and the upper glass, facing its bottom to the bottom of the lower glass. Each of the glasses is stepped, and the steps of smaller diameter are facing each other. Feeder line is made of three lengths of coaxial cable. First segment of the coaxial cable is selected with a characteristic impedance of 50 Ohms, and the second and third segments of the coaxial cable are selected with a characteristic impedance of 100 Ohms. First segment of the coaxial cable is passed along the longitudinal axis of the first dipole inside the glasses through their bottoms into the gap between the dipoles, its central core is connected with interconnected central cores of the second and third segments of the coaxial cable, and its braid with their braids. Second segment of the coaxial cable is passed along the longitudinal axis of the first dipole inside the upper glass through its bottom into the gap between the upper and lower glasses, its central core is connected to the bottom of the upper glass and the braid to the bottom of the lower glass. Third segment of the coaxial cable is passed along the longitudinal axis of the second dipole inside the bottom glass through its bottom into the gap between the upper and lower glasses, its central core is connected to the bottom of the upper glass and the braid to the bottom of the lower glass.

EFFECT: technical result consists in providing a radiation pattern without crushing the main lobe, reducing the SWR, reducing the longitudinal dimensions and simplifying the design.

4 cl, 3 dwg

Description

The invention relates to radio engineering, and in particular to broadband antennas of transceiver devices for communication between stationary objects or ground objects with a time-varying relative position thereof, operating in the DMV2 range. The invention relates to antennas with vertical polarization and a circular radiation pattern in the horizontal plane.

Antennas of the DMV2 range are known that use an asymmetric vibrator with a broadband matching device at the base, for example, MVDP500X6 from Hascall-Denke (USA), WB525G from CO JOT (Finland), AD-64 / A from TRIVAL ANTENE (Slovenia), RF-3186 -AT320 from HARRIS (USA) (sources of information on the Internet: www.hascall-denke.com, www.coiot.com, www.trivalantene.si, www.rf.harris.com).

The most complete technical specifications are given for the Hascall-Denke MVDP500X6 antenna: standing wave coefficient (SWR) in the frequency range of not more than 3.0, Ku gain in the range from -1.5 to 2.5 dBi. It should be noted that Ku is shown not in the direction of the horizon, but in the direction of maximum gain, which follows from the graph given in the specification of the antenna, which shows a “dip” in the direction of the horizon of more than -10 dBi at a frequency of 2450 MHz. In practice, in order to obtain the necessary communication range, Ku is important precisely in the direction of the horizon.

An asymmetric vibrator with a broadband matching device at the base has a small diameter, but has a small overlap coefficient in the frequency range. In addition, in such a device, additional losses are inevitable in the broadband matching device.

The use of dipole circuits constructed using coaxial cylindrical emitters has been known for a long time (see, for example, US patents US 2462865, US 3100893). However, such schemes do not have a sufficiently large frequency overlap coefficient, a radiation pattern with crushing of the main lobe, and a low gain in the horizontal direction.

From the patent of the Russian Federation RU 2629893, an ultra-wideband DMV2 antenna is known, built on one dipole, which is made using three radiating elements. In this antenna, three radiating elements are located on one longitudinal axis oriented vertically. The first lower radiating element is made in the form of an inverted glass. The second radiating element is made in the form of a cup facing its bottom to the bottom of the inverted cup of the first lower radiating element. The third radiating element is a rod made cylindrical, one end of which, the lower, is connected to the bottom of the glass of the second radiating element, and the other end, the upper, is located outside this glass. Coaxial cable is missing inside the inverted cup of the first lower radiating element. The braid of the coaxial cable is connected to the bottom of the inverted cup, and the central core of the coaxial cable through the hole in the bottom of the inverted cup is connected to the bottom of the cup of the second radiating element. The rod is made stepped, and the step is located inside the glass of the second radiating element.

The length of the glass of the second radiating element is made smaller than the length of the inverted glass of the first lower radiating element. The advantages of this antenna are a large frequency overlap coefficient and providing a radiation pattern without crushing the main lobe.

The limitations of the antenna according to RU2629893 are the insufficiently large gain in the horizontal direction (Ku from -2 to 3 dBi), and its radiation pattern depends on the shape and size of the site of the underlying surface on which the antenna is installed.

The closest to the claimed technical solution is a broadband antenna, described in the publication of international application WO 2004010527 and containing several dipoles located on the longitudinal axis, oriented vertically. Each of the antenna dipoles is made of two radiating elements, cylindrical and hollow, installed with a gap between them, which are electrically connected via a feeder line. In this antenna, dipoles are electrically connected in series, and its operating frequency range (broadband) of 500-2500 MHz is achieved by selecting a large number of dipoles, for example, from five to seven. The SWR value of such an antenna in the operating frequency range is from 3.5 to 6. The Ku value with a large choice of the number of dipoles is quite high, but with a non-circular (with dips) radiation pattern (MD) in the horizontal plane, which is due to the impossibility of a symmetrical sequential feeding a large number of dipoles. The use of a large number of dipoles leads to a significant increase in the longitudinal dimensions of the antenna.

The problem solved by the invention is the improvement of technical and operational characteristics.

The technical result achieved by using the invention is to provide a radiation pattern without crushing the main lobe, reducing the SWR, reducing the longitudinal dimensions and simplifying the design.

To solve the problem with achieving the claimed technical result in a broadband antenna containing at least two dipoles located on a longitudinal axis oriented vertically, each of the dipoles is made of two radiating elements, cylindrical and hollow, installed with a gap between them, which are electrically connected through the feeder line. According to the invention, each of the radiating elements of the dipole is made in the form of a glass: the lower glass, inverted, and the upper glass, facing its bottom to the bottom of the lower glass. Each of the glasses is made stepwise, and the steps of a smaller diameter are facing each other. The feeder line is made of three pieces of coaxial cable. The first segment of the coaxial cable is selected with a wave impedance of 50 Ohms, the second and third segments of coaxial cable are selected with a wave impedance of 100 Ohms. The first segment of the coaxial cable is passed along the longitudinal axis of the first dipole inside the cups through their bottoms into the gap between the dipoles, and its central core is connected to the connected central cores of the second and third segments of the coaxial cable, and its braid with their braids. The second segment of the coaxial cable is passed along the longitudinal axis of the first dipole inside the upper glass through its bottom into the gap between the upper and lower glasses, and its central core is connected to the bottom of the upper glass, and the braid to the bottom of the lower glass. The third segment of the coaxial cable is passed along the longitudinal axis of the second dipole inside the lower glass through its bottom into the gap between the upper and lower glasses, and its central core is connected to the bottom of the upper glass, and the braid is connected to the bottom of the lower glass.

Additional embodiments of the device are possible, in which it is advisable that:

- bushings made of ferrite were introduced, installed externally on the first, second and third segments of the coaxial cable;

- one of the bushings was installed externally on the first and second segments of the coaxial cable, and the other two on the first and third segments of the coaxial cable under the lower cups, respectively, of the first and second dipole and / or inside them;

- the radiating elements of the dipoles were made identical.

These advantages, as well as features of the present invention are explained with the help of a variant of its implementation with reference to the figure.

In FIG. 1 schematically shows the claimed design of an ultra-wideband antenna of the DMV 2 range.

In FIG. Figure 2 shows the directivity pattern in the vertical plane in the absolute values of Ku (dBi) in the operating frequency range.

In FIG. Figure 3 shows a graph of changes in the SWR frequency range of the fabricated antenna sample.

The antenna (Fig. 1) contains two dipoles 1, 2, which are located on the longitudinal axis Y-Y, oriented vertically. Each of the dipoles 1, 2 consists of two radiating elements - respectively, radiating elements 3.1, 4.1 and radiating elements 3.2, 4.2, made cylindrical and hollow, installed with a gap between them, and electrically connected via a feeder line. The radiating elements 3.1 and 3.2, respectively, of dipole 1 and dipole 2 are made in the form of an inverted glass (hereinafter also referred to as the “lower glass"). The radiating elements 4.1 and 4.2, respectively, of dipole 1 and dipole 2 are made in the form of a glass (hereinafter also referred to as the "upper glass"), facing its bottom to the bottom of the corresponding lower glass. Each of the upper and lower glasses is made stepwise, with steps of a smaller diameter facing each other.

The feeder line is made of three segments 5, 6, 7 of the coaxial cable.

The first segment 5 of the coaxial cable is selected with a wave impedance of 50 Ohms, and the second and third segments 6, 7 of a coaxial cable are selected with a wave impedance of 100 Ohms. The first segment 5 of the coaxial cable is passed along the longitudinal axis of the first dipole 1 inside its lower and upper glasses (radiating elements 3.1, 4.1) through their bottoms into the gap between the dipoles 1, 2. The central core of the first segment 5 of the coaxial cable is connected to interconnected central conductors the second and third segments 6, 7 of the coaxial cable, and its braid - with braids of the second and third segments 6, 7 of the coaxial cable.

The second segment 6 of the coaxial cable is passed along the longitudinal axis of the first dipole 1 inside the upper glass (radiating element 4.1) through its bottom into the gap between the upper and lower glasses (radiating elements 3.1, 4.1). The central core of the second segment 6 of the coaxial cable is connected to the bottom of the upper glass (radiating element 4.1), and the braid is connected to the bottom of the lower glass (radiating element 3.1).

The third segment 7 of the coaxial cable is passed along the longitudinal axis of the second dipole 2 inside the lower glass (radiating element 3.2) through its bottom into the gap between the upper and lower glasses (radiating elements 3.2, 4.2). The central core of the third segment 7 of the coaxial cable is connected to the bottom of the upper glass (radiating element 4.2), and the braid is connected to the bottom of the lower glass (radiating element 3.2).

The antenna also contains bushings 8, 9, 10 made of ferrite, mounted externally on the first, second and third segments 5, 6, 7 of the coaxial cable.

To simplify the construction, the embodiment shown in FIG. 1, in which one of the bushings 8 is mounted externally on the first and second segments 5, 6 of the coaxial cable, and the other two 9, 10, respectively, on the first and third segments 5, 7 of the coaxial cable, under the lower glasses 3.1, 3.2 of the first and second dipoles 1, 2 and / or inside them.

The radiating elements 3.1, 4.1 and 3.2, 4.2 of dipoles 1, 2 are made identical to improve coordination and simplify the design.

A broadband antenna operates as follows.

Unlike analogs, the proposed antenna was obtained by combining broadband emitters 3.1, 4.1 and 3.2, 4.2 of a special (step) design into a vertical antenna array in such a way that high Ku is achieved in a wide frequency range, and the total radiation pattern in the horizontal plane is kept circular by performing emitters in the form of stepped glasses.

The antenna consists of two identical symmetrical dipoles 1, 2, combined in a vertical antenna array. Each of dipoles 1, 2, in turn, is formed by two emitters 3.1, 4.1 and 3.2, 4.2 (hollow, step). The distance between dipoles 1, 2 is chosen to ensure uniform Ku in the range of operating frequencies. For example, the indicated distance can be selected in the range of about 15 to 60 mm.

The input impedance of each dipole 1, 2 is selected approximately 100 Ohms in the entire range of operating frequencies. For this, the geometric dimensions of the emitters 3.1, 4.1 and 3.2, 4.2 and the ratio of the diameters of the steps, which provide the necessary operating frequency band from 500 to 2500 MHz (see Fig. 3), and the maximum possible Ku of a separate dipole 1, 2 of the antenna array are selected. For example, the length of the emitters 3.1, 4.1 and 3.2, 4.2 in the specified range of operating frequencies can be from 40 to 60 mm, and the ratio of the diameters of the steps of the glasses is approximately 1.5 to 2.

The first segment 5 of a coaxial cable with a wave impedance of 50 Ohms passes inside the first dipole 1, consisting of emitters 3.1, 4.1. In the middle of the distance between dipoles 1, 2, the first segment 5 of the coaxial cable is connected to two equal to the length of the second and third segments 6, 7 of the coaxial cable with a wave impedance of 100 Ohms, which, unlike the closest analogue, are connected not in series, but in parallel.

The second segment 6 of the coaxial cable passes inside the emitter 4.1 and feeds the lower dipole 1 of the antenna array. The third segment 7 of the coaxial cable passes inside the emitter 3.2 and feeds the upper dipole 2 of the antenna array. Thus, in-phase power is provided for both dipoles 1, 2 and matching of the antenna input with a wave impedance of 50 Ohms.

To exclude common-mode currents flowing through the braids of segments 5, 6, 7 of the supply coaxial cables, bushes 8, 9, 10 made of ferrite can be put on them.

In FIG. 2 shows the calculated radiation pattern (ND) in the vertical plane in the absolute values of Ku (dB), and in FIG. 3 is a graph of the SWR of a fabricated antenna sample.

In FIG. 2 shows the DN curves for various discrete frequency values: 0.5 GHz; 0.75 GHz; 1.0 GHz; 1.25 GHz; 1.5 GHz; 1.75 GHz; 2.0 GHz; 2.25 GHz; 2.5 GHz. As can be seen, the main lobes of the DN have no noticeable dips, and the value of Ku increases with increasing frequency.

The SWR (Fig. 3) in the frequency range 500-2500 MHz in the entire range is significantly less than 3.0, and only in the high frequency range 2250-2500 MHz the SWR is approximately 3-5-4, which is still significantly lower than the closest analogue in this area and in the entire range of operating frequencies.

Reducing the longitudinal dimensions and simplifying the design is achieved through the use of fewer dipoles.

As for the comparison with the parameters achieved by the analog antenna according to RF patent RU 2629893, the claimed antenna has a significantly higher gain in the horizontal direction from plus 2 to plus 6 dBi (the known analog antenna is from minus 2 to plus 3), therefore, with the same input power, the radiated power of the claimed antenna is on average more than two times higher. Also, the radiation pattern of the declared antenna is much less dependent on the shape and size of the area on which the antenna is installed.

At the same time, the specialist will be clear that the claimed antenna may have various improvements that complement the features of the first claim. For example, to further increase Ku (if necessary), two more dipoles can be added, connected to the supply feeder, similarly to that proposed, with a corresponding choice of input impedances of radiating elements and wave impedances of connected segments of coaxial cables. Various modules can be placed in the cavity of the emitter glasses: low-noise amplifiers, power amplifiers, filters, etc.

The most successfully declared ultra-wideband antenna of the DMV2 range is industrially applicable for communication between stationary objects or mobile objects, for example, mobile radio stations.

Claims (4)

1. A broadband antenna containing two dipoles located on a longitudinal axis oriented vertically, each of the dipoles is made of two radiating elements, cylindrical and hollow, installed with a gap between them, which are electrically connected via a feeder line, characterized in that each of the radiating The elements of the dipole are made in the form of a lower glass - inverted, and an upper glass, facing its bottom to the bottom of the lower glass, each of the glasses is made stepwise, with a smaller diameter they are facing each other, the feeder line is made of three pieces of coaxial cable, with the first piece of coaxial cable selected with a wave impedance of 50 Ohms, and the second and third pieces of coaxial cable with a wave impedance of 100 Ohms, the first piece of coaxial cable is skipped along the longitudinal axis of the first a dipole inside its glasses through their bottoms into the gap between the dipoles, its central core is connected to interconnected central conductors of the second and third segments of the coaxial cable, and its braid is connected with with the lashes of the second and third segments of the coaxial cable, the second segment of the coaxial cable is passed along the longitudinal axis of the first dipole inside its upper glass through its bottom into the gap between the upper and lower glasses, its central core is connected to the bottom of the upper glass, and the braid is connected to the bottom of the lower glass, the third segment of the coaxial cable is passed along the longitudinal axis of the second dipole inside its lower glass through its bottom into the gap between the upper and lower glasses, its central core is connected to the bottom of the upper about the glass, and the braid - to the bottom of the lower glass. 2. The broadband antenna according to claim 1, characterized in that it contains bushings made of ferrite mounted externally on the first, second and third segments of the coaxial cable. 3. The broadband antenna according to claim 2, characterized in that one of the bushes is installed externally on the first and second segments of the coaxial cable, and the other two, respectively, on the first and third segments of the coaxial cable, under the lower glasses of the first and second dipole and / or inside them. 4. The broadband antenna according to claim 1, characterized in that the radiating elements of the dipoles are made identical.

Images