RU124516U1 - Fragment of a multi-element controlled strip of a phased antenna array L RANGE - Google Patents

Abstract

A fragment of a L-band multi-element controlled strip phased array antenna (PAR) containing a common passive reflector and symmetrical half-wave vibrators located in accordance with the PAR scheme perpendicular to the plane of the common passive reflector, each of which includes two vibrator arms that have a gap in the middle of the symmetry axis communications and are fed through a high-frequency (HF) cable in antiphase according to the top power circuit, as well as a balancing device and a short circuit, which form a short a short-circuited U elbow of length λav / 4, the distance from the middle of the vibrator arm to the common passive reflector is λav / 4, characterized in that the design of the symmetrical half-wave vibrator is made on one printed circuit board based on a double-sided PCB, in which at the level of the general passive reflector is placed on the axis of symmetry of the vibrator cable RF connector, in connection with which the topology of the short-circuited U elbow is made curved towards one of the shoulders of the vibrator, and the RF cable from the RF connector to the shoulders of the vibrator is laid n along a curved path in the form of a semicircle in the direction of the other arm of the vibrator, in addition, to expand the frequency bandwidth on one side of the printed circuit board, an open reactive loop with a communication window towards the vibrator is galvanically connected to the communication gap between the printed arms of the vibrator, perpendicular and symmetrical to the communication gap with the shoulders of a vibrator.

Description

The utility model relates to antenna technology, in particular, to multi-element strip microwave (UHF) antennas and can be used as a fragment of a phased antenna array (PAR), either independently or as part of complex transceiver systems.

There is a wide variety of multi-element microwave antennas containing ordering placed, in accordance with the geometry of the hexagonal or rectangular grid of PAR, certain emitters (vibrator, waveguide, etc.). Therefore, the technique of antennas follows the path of creating fundamentally new types of antennas and the path of improving and perfecting their design and production technology.

The following vibrators are widely used in the radio industry for headlights:

- using circuits with a U-bend for balancing the fields on the shoulders of the vibrators and their excitation; the excitation may be upper or lower relative to the passive reflector;

- using coupled lines with a length of a quarter of the average wavelength of the operating range (λav / 4), to balance the fields; excitation of coupled lines and vibrators - lower relative to the passive reflector;

- with excitation of the shoulders of the vibrators and the balancing of the fields with special structural schemes, for example, in high-frequency (HF) transitions from a three-wire high-quality strip line to a two-wire, exciting the shoulders of the vibrators; excitation is only lower relative to the passive reflector;

- using planar slotted strip waveguides on the same board as the shoulders of the vibrators to excite and symmetry the fields; excitation - lower relative to the passive reflector.

Known multi-element strip microwave antenna [1] containing symmetrically arranged strip printed vibrators, arranged in order to the plane of the common passive reflector, whose shoulders are powered in antiphase by symmetrical strip lines equipped with balancing-matching devices. Symmetrical strip vibrators are made in the form of prefabricated three-layer strip designs on three boards.

Along with the positive qualities of this type of vibrators (manufacturability, a wide band of transmitted frequencies), the disadvantage is the high cost of manufacturing one vibrator due to the use of RF connectors of own production and the irrational use of materials in the manufacture.

Known linear vibratory phased array [2], consisting of symmetrical half-wave vibrators on a single printed circuit board, located in the same plane above the conductive screen at a distance of λav / 4 and in-phase powered by elements of the feeder path.

In this headlamp, the printed arms of the vibrators have a feeding point from the feeder path through the RF connector located at the level of the plane of the conductive screen at the base of the vertical coupled printed lines passing over the length λcr / 4 into the arms of the vibrators at an angle of 90 °, and the printed conductors adjacent to the dot powering the vibrators, galvanically shorted to the housing at the junction with the conductive screen. In this case, the vertical printed sections of the excitation of the same and opposite shoulders of the vibrators are equipped with parallel matching plane planes matching capacitive flat conductive elements.

The disadvantage of this technical solution is that the structural circuit requires tuning due to the capacitive tuning element located on the back side of the board, or due to the introduction of additional capacitive resistance into the communication area. The narrowband circuit has RF losses due to the placement of print on one side of the board.

Known PAR [3], in which the vibrator is made on one printed circuit board. Excitation and symmetrization of the fields on the shoulders of the printed vibrator is carried out by a double-slit planar waveguide (or by three stripe connected lines formed by two slits of length cav / 4). The central strip is connected to the core of the RF connector, the left strip and the right strip are shorted to the housing of the RF connector. Excitation of the shoulders of the printed vibrator is carried out by galvanic connection with them of the left and central strips; the right strip together with the central strip form an open reactive loop. The effect of an open reactive loop on the vibrator arm should be minimal. This design scheme is easily adjusted by a capacitive element from the back of the board to a wide strip. The excitation in this design scheme is lower relative to the passive reflector, the passband is 31% in terms of the standing wave coefficient (SWR) = 1.3.

The disadvantages of this scheme include additional RF losses in the dielectric due to the printing on one side of the board, as well as the cost of the vibrator design due to the lack of commercially available RF connectors of the required dimensions.

Known PAR [4], which contains a common passive reflector and symmetric coaxial half-wave vibrators (see figure 1), located in accordance with the PAR scheme, perpendicular to the plane of the common passive reflector. The structure of the vibrators includes: two arms of the vibrator 1, which have a coupling gap in the middle of the axis of symmetry and are fed through the RF cables in antiphase according to the top supply circuit, as well as a balancing device 5 on symmetrical connected tubular lines with short circuit 3, forming a short-circuited U elbow of long λav / 4, while the distance from the middle of the shoulder of the vibrator 1 to the total passive reflector 2 is λav / 4. The feeding RF cable 4 passes in one of the tubes of the balancing device 5.

The use of a short-circuited U elbow in the design allows to reduce the RF currents flowing to the cable armor due to the infinitely large input resistance of the U elbow.

Tubular designs of vibrators for HEADLIGHTS have a number of significant disadvantages: high weight, low-tech, manufacturing requires large labor and financial costs. According to sources [5], structural schemes using the U elbow are narrow-band; special measures are required to expand the band of transmitted frequencies, for example, the inclusion of communication circuits in vibrators [6].

As a rule, such constructive solutions are used to create high-potential strategic headlights operating in a narrow frequency band. In the printed version, this design can be implemented on a single printed circuit board, the excitation of the vibrators is upper or lower relative to the passive reflector. For many other applications, headlamps are more commonly used with headlamps, but with lower radiated power levels.

The closest in technical essence, i.e. The prototype is a fragment of a phased array with half-wave coaxial vibrators [4].

The technical result of the proposed utility model is to improve the characteristics of the headlamp, in terms of expanding the frequency bandwidth, increasing its manufacturability and reducing the cost of manufacturing, modernization of the design by expanding the selection of materials and components (metallized fiberglass, RF cable, RF connectors).

The specified technical result is achieved in that in a fragment of a strip headlamp containing a common passive reflector and symmetric half-wave vibrators located in accordance with the scheme of the headlamp perpendicular to the plane of the common passive reflector, each of which includes two arms of vibrators that have a coupling gap in the middle of the axis of symmetry and are fed through the RF cables in antiphase according to the top supply circuit, as well as a balancing device and a short-circuiting device, which form a short-circuited U elbow with a length of λav / 4, the distance from the middle of the vibrator arm to the common passive reflector is λav / 4, the design of the symmetrical half-wave vibrator is made on one printed circuit board based on a double-sided PCB, in which a cable RF connector is placed along the axis of symmetry of the vibrator, therefore the topology of the short-circuited U knee is curved towards one of the arms of the vibrators, and the RF cable from the RF connector to the arms of the vibrators is laid along a curved path in the form of a half ring in a hundred to the side of the other arm of the vibrators, in addition, to expand the bandwidth of the frequencies, on one side of the printed circuit board an open reactive loop is introduced perpendicularly and symmetrically to the communication gap between the printed shoulders of the vibrators, galvanically connected to the shoulders of the vibrators and having a communication window in the center located opposite the gap connection of the shoulders of the vibrators.

As already mentioned above, this constructive scheme can be implemented with upper excitation in comparison with [2], [3] provided the bandwidth of the transmitted frequencies is expanded by 2–3 times. This is possible due to the introduction of open-loop reactive loops into the constructive scheme of half-wave vibrators, for example, on printed material of the ARLAN type. This material has the following characteristics: thickness t = 0.76 mm and dielectric constant ε = 3.0, which are necessary and sufficient to reduce microwave losses in the dielectric. Open reactive loops are placed on one side of the printed vibrators, perpendicularly and symmetrically to the communication gap between the shoulders of the vibrators. Open reactive loops are galvanically connected to the shoulders of the vibrators, for example, by soldering, in the center they have communication windows directed towards the vibrator opposite the communication gap of the shoulders of the vibrators. Open reactive loops do not require additional adjustment as part of the headlamp.

To implement this scheme, when the cable RF connector is located in the center of the board, a change in the topology of the U elbow is required - it must be curved with a bend at some angle to one side from the axis of symmetry of the vibrator, and the connecting RF cable from the RF connector to the shoulders of the vibrators with a slope in the form half rings to the other side.

Figure 2 shows a structural diagram of a printed half-wave vibrator of the claimed utility model, made on one printed circuit board based on a double-sided PCB:

1 - the shoulders of the vibrator;

2 - passive reflector;

3 - short circuit;

4 - power RF cable;

5 - a balancing device;

6 - RF connector;

7 - open reactive loop (RRS);

8 - printed circuit board (based on double-sided fiberglass).

The shoulders of the vibrator 1 are two rectangular strip conductors located on both sides of the printed circuit board 8 galvanically connected to the output ends of the balancing device 5, which together with the short circuit 3 form a short-circuited U elbow and located on one side of the printed circuit board 8.

The balancing device 5 is made in the form of a two-wire strip line with a curved topology. The RF cable 4 from the RF connector 6 is laid to the shoulders of the vibrator 1 along a curved path towards one of the vibrator arms in the form of a half ring on the same side of the circuit board 8 as the balancing device 5. The curved topology of the balancing device 5 and the feeding RF cable 4 is symmetrical with respect to axis of symmetry of the vibrator, which allows you to align the field on the shoulders of the vibrator 1 and maintain the position of the phase center in the center of the vibrator.

The RF connector 6 is installed on the printed circuit board 8 strictly along the axis of symmetry of the vibrator in the window of the printed circuit board, repeating the outlines of the RF connector 6; the RF connector 6 is attached to the circuit board 8 mechanically in two places (the RF connector housing and the nut tightening the RF connector parts after installing the RF cable into the connector are attached to the circuit board) (the attachment points are not shown in the figure).

On one side of the vibrator, strictly open in the center of the shoulders of the vibrator 1, symmetrically to its axis, an open jet loop 7 is installed, perpendicularly and symmetrically to the communication gap between the shoulders of the vibrators 1, to maximize the frequency bandwidth. A reactive open loop in the center has a communication window located opposite the communication gap of the vibrator arms.

The inventive fragment of a multi-element controlled strip phased array antenna array L range (figure 3) contains placed in a rectangular grid PAR, at a fixed distance from each other dx and dy, and at a height λav / 4 above the plane of the common passive reflector 2, symmetrical strip perpendicular to it half-wave vibrators made using the purchased housing of the RF connector 6.

The device (fragment PAR) works as follows:

During reception, a plane wave incident on the grating induces, including due to the passive reflector 2, antiphase voltages of equal amplitude and phase on the shoulders of the vibrators 1. Through the balancing schemes (5, 3) and excitation (4), with the participation of open reactive loops 7 (to expand the passband), the signal is fed to the RF connectors 6. These signals are summed through the summation and phasing systems of the antenna (not shown in the figures).

When transmitting, the probing RF signal from the PAR input through the antenna division and phasing system is fed to the RF cable connectors 6, RF cables 4, short-circuited U elbows (balancing devices 5 and short-circuit 3), open reactive loops 7, on the shoulders of vibrators 1, which and form the total radiation pattern, providing one-way radiation of the microwave signal into space thanks to the passive reflector 2.

Due to the introduction of an open reactive loop 7 into the vibrator circuits, due to the mutual compensation of the reactive components of the input resistance, the bandwidth is expanded no less than 2–3 times at the SWR level of 1.5–1.6, which ensures the beam sways at angles ± 45 ° from normal.

Figure 4 shows the experimental results on the SWR of a single vibrator on one board of the claimed fragment of the PAR.

Tests of 9-element PAR fragments with a step of dx = dy = 0.6λcp PAR, showed that in the 10% working band the level of SWR during beam swing in E and H (orthogonal) planes at angles of ± 45 ° does not exceed 2.1- 2.2, and for intermediate swing angles 15 ° -30 ° this value is significantly lower.

During testing, the PAR fragments were excited through an isolated power divider, and the beam of the PAR fragment was angled ± 45 ° from the normal position by changing the lengths of the RF cables fed.

Analyzing the frequency characteristics in accordance with figure 4, we can make a fundamental conclusion that in the frequency band at the level of the SWR equal to two (Δf≈500 MHz), the SWR in this band changes little and has a linear character, which is a necessary condition for ensuring oscillations of the main beam of the HEADLIGHT at angles of ± 45 ° in the working frequency band.

Currently, the enterprise has developed design documentation for the claimed device and produces a series of strip vibrators.

Thus, the introduction into the fragment of a multi-element controlled strip headlamp of the L range containing a common passive reflector and symmetric half-wave vibrators located in accordance with the PAR scheme is perpendicular to the plane of the common passive reflector, each of which includes two vibrator arms that have a gap in the middle of the axis of symmetry communication and are fed through a high-frequency (HF) cable in antiphase according to the upper power circuit, as well as a balancing device and a short circuit, which form a short-circuit a bent U elbow of length λav / 4, the distance from the middle of the vibrator arm to the common passive reflector is λav / 4, the design of a symmetrical half-wave vibrator made on one printed circuit board based on a double-sided PCB, in which at the level of the general passive reflector it is placed along the axis of symmetry of the vibrator RF cable connector, in connection with which the topology of the short-circuited U elbow is made curvilinearly towards one of the vibrator arms, and the RF cable from the RF connector to the vibrator arms is laid along a curved path In the form of a half-ring in the direction of the other arm of the vibrator, in addition, to expand the frequency bandwidth, an open reactive loop is introduced perpendicularly and symmetrically to the communication gap between the printed shoulders of the vibrator on one side of the printed circuit board with the communication window towards the vibrator, galvanically connected to the shoulders vibrator, allows to improve the manufacturability of the vibrator and reduce its cost, increase the modernization of the design, while in the working frequency band (~ 10%) provides the beam at angles of ± 45 ° in the E and H (orthogonal) planes, as in the prototype.

Bibliography:

1 Patent of the Russian Federation No. 2256261 dated July 10, 2005, application No. 2003126963 dated September 3, 2003, "Multi-element strip microwave antenna", authors Panfilov V.I., Shabalin A.V.

2 RF Patent No. 2264009 dated November 10, 2005, application No. 2004120214 dated July 1, 2004, "Linear Vibrated Phased Antenna Array", authors A. Anurin, A. Shabalin.

3 RF patent No. 90265 dated 12/27/2009, application No. 2009131919 dated August 24, 2009 "Broadband linear multi-element vibrator phased antenna array", authors Shabalin A.V., Tuzaev I.N.

4 Antennas and microwave devices. Designing phased array antennas. \ ed. D.I. Voskresensky. M .: Radio and Communication, 1981. p. 33 fig. 210, 211.

5 G.Z. Eisenberg. - Antennas of ultrashort waves. - M.: "State Publishing House of Literature on Communications and Radio", 1957. p. 262, 263, Fig. 13.1.XIII.

6 Scanning microwave systems t II Translation from English \ ed. G.T. Markov and A.F. Chaplin, vol. II., Soviet Radio M .: 1969, pp. 459-478.

Claims (1)

A fragment of a L-band multi-element controlled strip phased array antenna (PAR) containing a common passive reflector and symmetrical half-wave vibrators located in accordance with the PAR scheme perpendicular to the plane of the common passive reflector, each of which includes two vibrator arms that have a gap in the middle of the symmetry axis communications and are fed through a high-frequency (HF) cable in antiphase according to the top power circuit, as well as a balancing device and a short circuit, which form a short a short-circuited U elbow of length λav / 4, the distance from the middle of the vibrator arm to the common passive reflector is λav / 4, characterized in that the design of the symmetrical half-wave vibrator is made on one printed circuit board based on a double-sided PCB, in which at the level of the general passive reflector is placed on the axis of symmetry of the vibrator cable RF connector, in connection with which the topology of the short-circuited U elbow is made curved towards one of the shoulders of the vibrator, and the RF cable from the RF connector to the shoulders of the vibrator is laid n along a curved path in the form of a semicircle in the direction of the other arm of the vibrator, in addition, to expand the frequency bandwidth on one side of the printed circuit board, an open reactive loop with a communication window towards the vibrator is galvanically connected to the communication gap between the printed arms of the vibrator, perpendicular and symmetrical to the communication gap with the shoulders of a vibrator.

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