RU195632U1 - Two-channel transceiver antenna system with improved polarization isolation characteristic - Google Patents

Abstract

The utility model relates to antenna technology. A two-channel transceiver antenna system with an improved characteristic of the isolation level for polarization is characterized by the fact that it consists of the following elements: mirror (reflector); a multi-element waveguide irradiator made in the form of a four-element grating of the open ends of rectangular waveguides with a cross section of 19 × 9.5 mm, the wide walls of the waveguides being orthogonal to each other, mutually perpendicular plates are installed in the center of the irradiator, and the plate thickness ranges from 0.05λ to 0 , 1λ, plate height 0.25λ to 0.5λ. The technical result is to reduce energy leakage beyond the edges of the open end of the waveguide and to increase the isolation between the receiving and transmitting emitters. 7 ill.

Description

The proposed model of the antenna system relates to the field of antenna technology and can be used in radiolocation when constructing experimental radar stations with a fully polarized mode of sounding the space with the characteristics of the probing signals and technical requirements:

- pulse duration τ _u = 1 ... 400 μs;

- spectrum width of the probe signal

- carrier frequency

- radiation power P _rad = 1 W;

- provide independent emission and reception of signals in vertical and horizontal polarizations;

- the level of isolation in polarization between channels for radiation of -40 dB;

- the isolation level between polarization between channels at the reception is -40 dB;

- The level of isolation between the transmitting and receiving channels is -40 dB;

- the width of the antenna pattern 5 ° (angular degrees);

- the difference in the directions of the main maxima between the channels (RPU-PRU; RPrU-RPrU; PRU-RPrU) 2 ° (angular degrees);

From the current level of technology, a mirrored antenna with a cylindrical surface is known to obtain a Kosekan radiation pattern with a linear irradiator [Korbansky I.N. Antennas - M .: Energy, 1973, p. 239]. The disadvantage is the absence of a phase center in the irradiator, which does not allow the use of such an antenna for broadband radar.

A known irradiator of a monopulse radar antenna containing a four-section horn connected to a waveguide path made according to a scheme with four total-difference bridges on double waveguide tees (Leonov A.I., Fomichev K.I. Monopulse radar. - M .: Radio and communication , 1984.- 312 p. - S. 28-29). This irradiator has the best electrical characteristics, but it also has disadvantages: the irradiator only works with linear polarization of the electromagnetic field; the input of the transmitting channel and the output of the total receiving channel of the irradiator are combined; when such a scheme is implemented in the form of a design using separate waveguide nodes, it is necessary to adjust the irradiator in order to equalize the electric channel lengths and signal amplitudes in the waveguide channels.

The closest analogue of the utility model is a mirror offset antenna, for example, from satellite television (STV antennas), which are currently produced commercially [STV-0.55-1.1 0.55 St AUM Model: KU-BAND http://www.supral.ru/ p0202.html circulation date: 06/20/2019] (the characteristics are presented in table 1). It is proposed to fulfill these technical requirements on the basis of such an antenna.

The disadvantage of the prototype is:

1. Low decoupling by polarization.

2. Not ensuring the operation mode of simultaneous transmission and reception of radiation.

The design of the proposed utility model is illustrated by drawings:

- in FIG. 1 shows the design of offset antenna with mount;

- in FIG. 2 arrangement of waveguides and an absorber in a four-channel irradiator;

- in FIG. 3 section of the irradiator model with a matching device;

To meet the technical requirements, the model uses a mirror antenna located in its focus, in contrast to the prototype of a multi-element waveguide feed made in the form of a four-element array of open ends of rectangular waveguides with a cross section of 19 × 9.5 mm, and the wide walls of the waveguides are orthogonal to each other (Fig. 2). In this drawing:

- PFP B - receiving channel of vertical polarization;

- PFP G - receiving channel of horizontal polarization;

- PRD B - transmitting channel of vertical polarization;

- PRD G - transmitting channel of horizontal polarization.

A short circuit is installed at the opposite end from the open edge of the waveguide. A sectional view of the irradiator model is shown in FIG. 3.

от короткозамыкателя установлен SMA разъем, например SMA KFD-21, резьбовая часть которого находится на наружной поверхности волноводов, а выступающий внутренний проводник диаметром 2,3 мм входит внутрь волновода образуя волноводно-коаксиальный переход. Глубина погружения ≈0,15 λ_В. Поскольку коэффициент стоячей волны (КСВ) открытого конца волновода сечением 19×9,5 мм на частоте 10 ГГц имеет значение 1,7-1.8, то для лучшего согласования на расстоянии ≈0,32 λ_В от открытого конца волновода устанавливается реактивная неоднородность в виде латунного стержня высотой ≈0,05 λ_В и диаметром ≈0,05 λ_В, при этом КСВ излучателя становиться равным 1,2-1,25 во всем диапазоне частот. На фиг. 4, 5 показаны расчетные значения коэффициента стоячей волны для не согласованного и согласованного излучателя, выполненные в программе электро-динамического моделирования HFSS.On distance

an SMA connector is installed from the short circuit, for example, the SMA KFD-21, the threaded part of which is on the outer surface of the waveguides, and the protruding inner conductor with a diameter of 2.3 mm enters the waveguide forming a waveguide-coaxial transition. Immersion depth ≈0,15 λ _B. Since the standing wave coefficient (SWR) of the open end of the waveguide with a cross section of 19 × 9.5 mm at a frequency of 10 GHz is 1.7–1.8, for better matching at a distance of ≈0.32 λ _V from the open end of the waveguide, a reactive inhomogeneity is established in the form a brass rod with a height of ≈0.05 λ _V and a diameter of ≈0.05 λ _V , while the SWR of the emitter becomes equal to 1.2-1.25 in the entire frequency range. In FIG. Figures 4 and 5 show the calculated values of the standing wave coefficient for an inconsistent and consistent emitter performed in the HFSS electrodynamic simulation program.

In FIG. Figures 6 and 7 show the calculated attenuation in a waveguide-coaxial junction (CSC) of an uncoordinated and consistent radiator.

To reduce energy leakage beyond the edges of the open ends of the waveguides and to increase the isolation between the receiving and transmitting channels, mutually perpendicular plates are installed in the center of the irradiator (Fig. 2), from a material that absorbs high-frequency energy of grade 19 according to OST 107.460007.006-92 (of the following composition: epoxy resin ED-16 GOST 10587-84, polyester No. 1 TU 6-05-1122, talc TU 21-25-207, carbonyl iron GOST 13610-79, iso-MTGFA TU 6-09-33, accelerator UP-606/2 TU 6-094136-75). The thickness of the plates is in the range from 0.05λ to 0.1λ, the height of the plates is from 0.25λ to 0.5λ. Installing the plates allows you to increase the isolation between the reception and transmission channels to -40 dB.

BIBLIOGRAPHY

1. Broadband four-beam mirror antenna (Options) patent No. 2099836

2. The irradiator of the parabolic antenna

3. Monopulse irradiator patent No. 2188484

4. Monopulse antenna device patent No. 2236729

5. OST 107.460007.006-92. Materials for volume absorbers of high-frequency energy, official publication, 1993. Amendment No. 1 dated July 31, 2002, was introduced by Decision No. 196 dated November 1, 2002.

Claims (1)

A two-channel transceiver antenna system with an improved characteristic of the isolation level for polarization, characterized in that it consists of the following elements: mirror (reflector); a multi-element waveguide irradiator made in the form of a four-element grating of the open ends of rectangular waveguides with a cross section of 19 × 9.5 mm, the wide walls of the waveguides being orthogonal to each other, mutually perpendicular plates are installed in the center of the irradiator, and the plate thickness ranges from 0.05λ to 0 , 1λ, plate height 0.25λ to 0.5λ.

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