RU189383U1 - Multi-band dipole antenna - Google Patents

Abstract

The utility model relates to antenna technology and can be used as a transmitting, receiving or receiving and transmitting antenna of VHF range in mobile radio communications systems. A multi-band dipole collinear antenna contains a carrier metal support in the form of a pipe on which N vertical vibrators are located. Moreover, the upper and lower shoulders of each vibrator are made in the form of coaxially supporting metal cylinders, electrically connected to the support in the upper parts. Additional cylinders are inserted into each of the N-1 vibrators, providing a decoupling between the vibrators; The Nth vibrator is made in the form of a disc cone emitter consisting of a metal disk and a metal cone located at the top of the support and providing operation in a wide frequency range. The technical result is to provide the ability of the antenna in several narrow frequency bands, good isolation between the vibrators, as well as the possibility of radiation of broadband signals. 3 il.

Description

The proposed device relates to antenna technology and can be used as a transmitting, receiving or receiving and transmitting antenna VHF range in mobile radio systems.

Known broadband antenna in US Pat. RF 2656034, H01Q 9/18, consisting of two broadband emitters, bulk vibrators and decoupling devices. The disadvantages of such an antenna are the presence of complex decoupling devices, the need to provide separate counterweights for each type of radiator, which leads to the structural complexity of the final product and high weight and size parameters. Along with this, various variants of collinear antennas are also known according to the patents of the Russian Federation 2097883, H01Q 9/18; 2107364, H01Q 9/18; 2498466, H01Q 9/18. The disadvantage of such antennas is the ability to work only in a narrow frequency range.

The closest analogue to the technical nature of the proposed utility model is a compact vertical antenna array of vertical vibrators, spatially combined with a support in US Pat. RF 2573224, H01Q 9/18 (claims 1 and 4), adopted for the prototype.

The layout of the prototype device is shown in FIG. 1a, b, where indicated:

4 - support;

1, 2, 3 - first, second, third vibrators;

1.1 - the lower resonator of the first vibrator;

1.2 - the upper resonator of the first vibrator;

2.1 - the lower resonator of the second vibrator;

2.2 - the upper resonator of the second vibrator;

3.1 - the lower resonator of the third vibrator;

3.2 - the upper resonator of the third vibrator;

5.1 - coaxial cable;

8 - jumper.

The prototype device (claims 1, 4) contains the theoretically unlimited number of vibrators N. Consider the specific design, described in most detail in the prototype, with N = 3. In this design, the prototype device contains a support 4, which is a hollow metal pipe, three identical vibrators 1, 2, 3 are installed coaxially with it, each of which consists of identical resonators — the lower resonator (1.1, 2.1, 3.1) and the upper resonator ( 1.2, 2.2, 3.2). Each resonator is a hollow metal cylinder connected to the support by jumper 8 (Fig. 1b), while in the lower section there is no electrical contact between the resonators (1.1, 1.2, 2.1, 2.2, 3.1, 3.2) and the support 4. FIG. 1b shows the power supply unit of the vibrator in cross section. Between the lower and upper arms of the vibrator — resonators 1.1 and 1.2 — in support 4 there is an opening to which a coaxial cable 5.1 fits, which feeds this vibrator. The coaxial cable includes braid, which in the hole area is electrically connected to support 4, and the central conductor (core) of the cable, which is connected to the lower edge of the upper arm cylinder (upper resonator 1.2). To the second and third vibrators 2 and 3, similarly to vibrator 1, separate coaxial cables are connected, not shown in Figure 1.a.

The device prototype works as follows.

вблизи центральной частоты

. Each coaxially located vibrator 1, 2, 3, which is part of the antenna, is powered through a corresponding independent coaxial cable located inside support 4. Only a T-wave can propagate in a coaxial cable, while the current flowing from such a cable along the center conductor (current I₂ in the vibrator 1) is equal to the current flowing into the cable along the inner surface of its braid (current I_one in the vibrator 1). Current I₂ spreads on the outer and inner surface of the upper resonator 1.2 (currents I₂₁ and I₂₂, respectively), with the main part of the current I_oneflows on the outer surface resonator cylinder 1.2. Similarly current I_one also consists of two currents I_eleven and I₁₂. Given the smallness of the currents I₁₂ and I₂₂It can be considered that the vibrator is excited symmetrically. However, it is necessary to take into account some shunting effect of the resonator. The power supply units of the second and third vibrators 2 and 3 with corresponding independent coaxial cables (not shown in Fig. 1) look similar to the power supply unit of the vibrator 1 with the first coaxial cable 5.1. Thus, a compact vertical antenna array of vertical vibrators, spatially aligned with the support, is in good agreement with the power lines and will effectively emit electromagnetic energy in a narrow frequency band.

 near the center frequency

.

In the upper cross section of the upper arm of the vibrator 1.2, the current from the external surface of the cylinder of the resonator 1.2 along jumper 8 freely flows to the support 4, exciting it. This can lead to asymmetry of the vibrator arms and the corresponding distortion of the radiation pattern. This effect is manifested by the weaker, the closer to each other are the vibrators 1, 2, 3, since the free areas of the support 4, which extend the upper shoulders of the vibrators, decrease. With a sufficiently close arrangement of the vibrators, a strong connection will be observed between them, due to the presence of a large end-cap. To compensate for this capacitance, in order to improve the mutual isolation of vibrators, shortened resonators are used. Thus, matching and balancing the antenna is achieved by selecting the geometric parameters of the resonators included in the vibrators.

The disadvantage of the prototype device is the ability to work only in one narrow frequency range.

The objective of the proposed device is to enable independent operation of the antenna in several narrow frequency bands, including in a wide frequency range due to the introduction of a broadband radiator (vibrator) into the design, as well as ensuring good isolation between the vibrators.

To solve this problem, an antenna containing a carrier metal support in the form of a pipe, on which N vertical vibrators are located, the upper and lower shoulders of each vibrator being made as coaxial support of metal cylinders electrically connected to the support in the upper parts, according to the utility model additional cylinders were introduced from the N-1 vibrators, providing a decoupling between the vibrators; The Nth vibrator is made in the form of a disco-cone emitter, consisting of a metal disk and a metal cone, located on the top of the support and providing work in a wide frequency range.

FIG. 2 shows the scheme of the proposed device, where indicated:

1, 2, N-1 - vibrators;

1.1, 2.1, N-1.1 - lower resonators;

1.2, 2.2, N-1.2 - upper resonators;

1.3, 2.3, N-1.3 –additional metal cylinders;

N - disco-cone emitter (vibrator);

N.1 - metal disk;

N.2 - metal cone;

4 - support.

Consider a specific design, with N = 3, one vibrator is a disco cone emitter. FIG. 3 a, b shows the scheme of the proposed device, where indicated:

1 - upper range vibrator;

1.1 - the lower resonator of the upper range;

1.2 - upper resonator of the upper range;

1.3 - the first additional metal cylinder;

2 - low range vibrator;

2.1 - the lower resonator of the lower range;

2.2 - the upper resonator of the lower range;

2.3 - the second additional metal cylinder;

3 - disco cone emitter (vibrator);

3.1 - metal disc;

3.2 - metal cone;

4 - support;

5.1 - the first coaxial cable;

5.2 - second coaxial cable;

5.3 - the third coaxial cable;

8 - jumper.

The proposed antenna device contains a support 4, which is a metal pipe, coaxially with which, N vibrators (2, 3, ..., N) are installed, N-1 of which (2, 3, ..., N-1) consist of the top (2.2 , 3.2, ..., N-1.2) and lower (2.1, 3.1, ..., N-1.1) resonators and an additional metal cylinder (2.3, 3.3, ..., N-1.3), and the Nth vibrator, which is a disk-cone radiator N and consisting of a metal disk N.1 and a metal cone N.2. Moreover, the vibrator, which is a disk cone emitter, is located at the top of support 4. In the general case, the vibrators that make up the various resonators can have different geometrical dimensions. Each vibrator is connected to a separate power cable (feeder), which is a coaxial cable, the cable connection is considered on the example of a specific design (Fig. 3 b). In fig. 2 cables not shown.

The specific design with N = 3, shown in Fig. 3, contains support 4 and a vibrator of upper range 1, mounted on it coaxially, consisting of the upper 1.1 and lower 1.2 resonators and the first additional metal cylinder 1.3, the vibrator of the lower range 2, consisting of the upper 2.1 and a lower 2.2 resonator of the lower range and a second additional metal cylinder 2.3, and a disk-cone emitter (vibrator) 3, including a metal disk 3.1 and a metal cone 3.2. Each resonator (1.1, 1.2, 2.1, 2.2), as well as the first (1.3) and second (2.3) additional metal cylinders, are hollow thin-walled metal cylinders connected to the support by jumper 8, with electrical contact between the resonators in the lower section (1.1, 1.2, 2.1, 2.2), additional cylinders (1.3, 2.3) and support 4 is missing. Inside the support 4 are placed the first, second and third coaxial cables 5.1, 5.2, 5.3. FIG. 3b shows the power supply unit of the vibrator in section. Between the lower and upper arms of the vibrator — resonators 1.1 and 1.2, there is a hole in the support to which the first coaxial cable 5.1 of this vibrator fits, the braid of which in the hole area is electrically connected to support 4 and its central conductor (core) of the cable upper arm (upper resonator 2.2). The power supply unit of the low-range vibrator 2 with the second coaxial cable 5.2 (not shown in Fig. 3b) looks similar to the power supply unit of the vibrator 1 with the first coaxial cable 5.1. The braid of the third coaxial cable 5.3 is electrically connected to the metal cone 3.2, and its central core to the metal disk 3.1 (not shown in Fig. 3b).

The proposed device works as follows.

вблизи центральной частоты

. Consider the operation of the device on the example of a specific design (Fig. 3) with three vibrators, one of which is a disk-cone radiator. In coaxial cables 5.1, 5.2, 5.3, a T-wave propagates from a source of disturbances. Consider the vibrator 1, designed to work in a narrow range at high frequency. Each cylinder constituting the vibrator 1 has a size approximately equal to a quarter of the wavelength at the center frequency of the operating range, taking into account the shortening factor. The current I ₂ flows out of the center conductor of the first coaxial cable 5.1, spreads across the outer surface of the resonator 1.2, and the current I ₁ spreads across the outer surface of the resonator 1.1, not flowing into the braid of the coaxial cable 5.1, since the latter is electrically connected to support 4 having zero potential. . In this case, the internal surfaces of the resonators 1.1 and 1.2 together with the jumpers 8 perform the role of a quarter-wave volumetric blocking circuit, known in the literature as a “quarter-wave glass”. Due to the blocking effect of such a circuit, no currents flow along the internal surfaces of resonators 1.1 and 1.2 at the resonant frequency. However, due to the influence of neighboring vibrators, the resonant frequency can shift, in addition, currents at frequencies close to the resonance, but not equal to it, can flow on the inner surface of the vibrators, as well as on support 4. The first additional metal cylinder 1.3 is also a quarter-wave blocking resonator. Due to the presence of the first additional metal cylinder 1.3, located close enough to the upper resonator 1.2, the current I ₂ does not flow to the support 4, which allows to maintain the symmetry of the vibrator and its coordination with the power line. In addition, the bulk insulator, consisting of the first additional metal cylinder 1.3 and jumper 8, provides isolation of vibrators 1 and 2. Thus, the vibrator 1 provides good alignment with the power line and effective radiation in a narrow frequency band.

near the center frequency

.

вблизи центральной частоты

, значение которой превышает значение

более чем на

. The low-range vibrator 2 has a similar power supply with a second coaxial cable 5.2. In general, its operation is similar to that of the vibrator 1.2, but its operating frequency is approximately two times lower than the operating frequency of the vibrator 1, respectively, the size of the resonators and the additional cylinder (2.1, 2.2, 2.3) are approximately two times larger than those of the resonators and the cylinder (1.1, 1.2, 1.3) in the vibrator 1. The second additional metal cylinder 3.3, together with jumper 8, also represents a volume insulator and allows to provide a decoupling of the low-range vibrator 2 and the disk-cone emitter 3. The low-range vibrator 2 consistent with the power line and effectively radiates electromagnetic energy in a narrow band

near the center frequency

whose value exceeds the value

more than

.

. В общем случае не существует теоретического ограничения как на возможное число рабочих диапазонов частот антенны, так и на число используемых в антенне вибраторов. Излучаемое каждым из вибраторов, в том числе и диско-конусным излучателем, антенны электромагнитное поле имеет волновой фронт, близкий к сферическому, следовательно, антенна характеризуется круговой диаграммой направленности в азимутальной плоскости. Антенна обладает линейной вертикальной поляризацией. Согласование антенны не зависит от плоскости земли, поэтому, с точки зрения вопросов согласования, антенну можно размещать на любых поверхностях. The disco-cone emitter 3 is powered by a third coaxial cable 5.3 with a characteristic impedance of 50 Ohms, through which a T-wave propagates from a source of disturbances. A coaxial cable 5.3, connected by braiding to a metal cone 3.2, and a central conductor (residential) cable to a metal disc 3.1, excites an electromagnetic field that is radiated from the external surfaces of the disk-cone emitter 3 into the surrounding space. Disc cone emitter 3 is broadband and capable of matching with the power line and effective radiation in a wide frequency range

. In general, there is no theoretical limit on both the possible number of working frequency ranges of the antenna and the number of vibrators used in the antenna. The electromagnetic field emitted by each of the vibrators, including the disco-cone emitter, antenna, has a wave front that is close to spherical, therefore, the antenna is characterized by a circular radiation pattern in the azimuthal plane. The antenna has linear vertical polarization. The antenna matching does not depend on the ground plane, therefore, in terms of matching issues, the antenna can be placed on any surfaces.

Thus, in comparison with the prototype, the proposed antenna has the ability to work independently in several narrow frequency ranges, thanks to the use of vibrators of different sizes, and also has a good isolation between the vibrators, due to the introduction of additional cylinders into the antenna. In addition, unlike the prototype, the design has a broadband emitter, which allows you to work in both narrow and wide frequency ranges.

Claims (1)

A multi-band vibrator collinear antenna containing a carrier metal support in the form of a pipe on which N vertical vibrators are located, the upper and lower shoulders of each vibrator being made in the form of coaxial support of metal cylinders electrically connected to the support in the upper parts, characterized in that each of N-1 vibrators introduced additional cylinders, providing isolation between the vibrators; The Nth vibrator is made in the form of a disco-cone emitter, consisting of a metal disk and a metal cone, located on the top of the support and providing work in a wide frequency range.

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