RU148180U1 - Fragment of a multi-element controlled strip of a phased antenna array L RANGE - Google Patents

Abstract

1. A fragment of a multi-element controlled strip phased array antenna (PAR) of the L range, containing a common passive reflector, symmetrical half-wave vibrators and cable RF connectors located along the axis of symmetry of the vibrators at the level of the common passive reflector, which serve as structural elements for mechanical mounting of printed circuit boards, vibrators made on one double-sided printed circuit board and arranged in accordance with the PAR scheme perpendicular to the plane of the common passive reflector, each vibrat p includes two arms that are in the middle of the symmetry axis due gap and energized by radio frequency (RF) cable extending from the RF connector in antiphase upper supply circuit; on one side of the printed circuit board perpendicularly and symmetrically to the communication gap between the printed shoulders of the vibrator there is an open reactive loop with a communication window towards the vibrator, galvanically connected to the shoulders of the vibrator, and also a short-circuited balancing device in the form of a U elbow on connected strip lines, while the distance from the middle of the shoulder of the printed vibrator to the common passive reflector is λav / 4, characterized in that the topology of the short-circuited balancing device in the form of U count The pair is made symmetrical with respect to the axis of symmetry of the vibrator and horizontally located, and the RF supply cable is located in the center on the back of the printed vibrator perpendicular to the printed strip conductors of the modified U elbow at the level of the common passive reflector, in addition, to expand the frequency bandwidth and

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.

Currently, there is a wide variety of multi-element microwave antennas, containing strip vibrators above a common reflector arranged in order, in accordance with the geometry of the hexagonal or rectangular grid of the PAR.

The most appropriate is the use of existing antennas and vibrators in order to modernize them, improve their parameters, design, manufacturability, quality of equipment of antenna systems and their components.

In the radio industry, in television systems, and cellular communication systems, antennas are widely used using vibrators with an upper excitation (with a U-elbow) to ensure symmetrical fields on the shoulders of half-wave vibrators; excitation can also be lower relative to the plane of the passive reflector. Other excitation schemes are possible.

A classical device [1] is known that is close in technical essence — a fragment of a phased array containing half-wave coaxial vibrators located in accordance with the phased array scheme perpendicular to the plane of a common passive reflector. The composition of each vibrator includes: two arms of the vibrator, which have a coupling gap in the middle located along the axis of symmetry of the vibrator, and are fed through the RF cable in antiphase according to the upper supply circuit and a balancing device on symmetrical connected tubular lines with a short circuit, forming a U elbow of length λ / 4, the distance from the middle of the vibrator arm to the common passive reflector is λav / 4. The power RF cable runs in one of the tubes of the balancing device.

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

The disadvantage of this analogue is its tubular design, which is not technologically advanced, its manufacture is expensive and a similar design of HEADLIGHTS has a large weight,

According to the source [2], structural schemes using the U elbow are narrow-band; special measures are required to expand the frequency bandwidth, for example, the inclusion of communication circuits in the vibrator [3].

As a rule, the above-described design of a tubular vibrator is used in high-potential strategic headlights operating in a narrow frequency band. In a printed version at lower power levels, this design can be implemented on a single printed circuit board.

The closest in technical essence to the claimed utility model, i.e. the prototype (see Fig. 1) is a fragment of the PAR [4], which contains the PAR located in a rectangular grid, at a fixed distance from each other dx and dy, and at a height of cav / 4 above the plane of the common passive reflector 2, perpendicular to it symmetrical strip half-wave vibrators 1 with upper excitation, made using a purchased RF connector 6. The shoulders of each vibrator 1 are two rectangular strip conductors with a coupling gap in the middle along the axis of symmetry. The shoulders of the vibrator 1 are located on both sides of the printed circuit board 5 and are galvanically connected to the output ends of the short-circuited balancing device 3, made in the form of a U elbow and located on one side of the printed circuit board 5.

The balancing device 3 is made in the form of a two-wire strip line with a curved topology in the direction of one of the shoulders of the vibrator 1 in the form of a U elbow. The RF cable 4 from the RF connector 6 is laid to the shoulders of the vibrator 1 along a curved path towards the other arm of the vibrator in the form of a half ring, with the RF cable 4 located on the same side of the circuit board 5 as the balancing device 3.

The RF connector 6 is installed on the printed circuit board 5 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 printed circuit board 5 mechanically in two places (the attachment points are not shown in the figure).

On the opposite side of the vibrator relative to the balancing device 3 and the RF cable 4, an open reactive cable 7 is installed perpendicularly and symmetrically to the coupling gap between the shoulders of the vibrators 1 to maximize the frequency bandwidth on the shoulders of the vibrator 1 symmetrically to its axis. A reactive open loop in the center has a communication window located opposite the communication gap of the vibrator arms. A reactive open loop performs the functions of a tuning element and provides, with appropriate settings, an increase in the passband of the vibrator by a factor of 2–3.

In particular, at the applicant enterprise, the prototype is used in the PAR L range with a total number of 1824 vibrators.

In the production process, a number of shortcomings were revealed: a certain shift in the phase center of the vibrators; the complexity of manufacturing a feeding device - a HF cable in the form of a half ring; some mutual influence of the curved U-bend and metal staples that secure the printed circuit board to the RF cable connector.

As part of a large PAR, the shift of the phase center of the vibrators has little effect on the overall radiation pattern, but when using a single vibrator or as part of a small fragment of the PAR, it is advisable to eliminate it.

The technical result of the utility model is the improvement of technical and economic characteristics in terms of manufacturability, reducing the cost of manufacture and expanding the bandwidth of transmitted frequencies.

The specified technical result is achieved by the fact that in the fragment of the strip headlamp containing a common passive reflector, symmetrical half-wave vibrators and cable RF connectors located along the symmetry axis of the vibrators at the level of the general passive reflector, which serve as a structural element for mechanical mounting of printed circuit boards, each vibrator is made on one double-sided printed circuit board with two shoulders connected to each other through a communication gap located along the axis of symmetry of the vibrators, which are powered through the RF cable in antiphase according to the top power circuit; on one side of the printed circuit board perpendicularly and symmetrically to the communication gap between the printed arms of the vibrator there is an open reactive loop with a communication window towards the vibrator and galvanically connected to the arms of the vibrator, and also on the printed circuit board there is a short-circuited balancing device made on connected strip lines in the form of U of the knee, while the distance from the middle of the shoulder of the printed vibrator to the common passive reflector is λav / 4, and the RF supply cable is placed on one side of the ne atnoy board along the symmetry axis of the vibrator, and on the reverse side of the printed circuit board has a short-circuited balun which is formed on the coupled strip lines to a knee with a modified U topology of the inclined horizontally disposed in symmetrical relative to the symmetry axis of the vibrator; An RF cable to reduce mutual influence on the balancing device (U elbow) crosses it at right angles and is located on the back of the printed circuit board; U elbow brought to the input terminals and formed of two Π-shaped sections from connected strip lines with a length of λav / 8; the strip lines are connected in series with each other, with the total length of the knee U being λav / 2, in addition to extending the frequency bandwidth and increasing the resonant length of the vibrators, the topology of the vibrator arms is made with 90 ° bends towards the passive reflector and at the bend points matching bevels at an angle of 45 °.

The inventive fragment of a multi-element controlled strip headlamp L range (see Fig. 2) contains placed in a rectangular grid, 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 1, made using a purchased RF connector with a cross section of 7 × 3.

To implement the presented design scheme, the RF cable connector is installed in the center of the board, which in turn led to a change in the topology of the short-circuited balancing device in the form of a U elbow, in addition, the RF cable and the short-circuited device are located on opposite sides of the printed circuit board. The circuit is symmetrical about the axis of symmetry of the vibrator with the location of the connected conductors of the U elbow in the horizontal plane, and the input ends of the U elbow coincide with the excitation points of the arm of the vibrator RF cable. To ensure the same potential of the 2-sided printed vibrator, the excitation points of the vibrator are galvanically closed using hollow rivets and, to guarantee a short circuit, are additionally connected by soldering. Thus, each half of the U of the knee is λsr / 8 and soldered at the point of short circuit, i.e. To the right and left of this short circuit point are two horizontally oriented half loops on connected conductors connected in series.

This scheme significantly reduces the vertical size of the U elbow, allows you to install the cable RF connector with a height of 32 mm in the center of the printed circuit board and allows you to place the feeding RF cable strictly along the axis of symmetry of the vibrator, i.e. provide central excitement.

Structurally, the printed circuit board with the help of a cable RF connector is rigidly attached to the RF connector, the vibrator shoulders are excited by an RF cable of the brand RK-50-2-25 with metal semi-rigid armor.

In FIG. 3 shows a structural diagram of a half-wave vibrator of the claimed fragment of the PAR, where:

1. the shoulders of the vibrator;

2. passive reflector;

3. balancing device (U elbow);

4. power RF cable;

5. printed circuit board (based on 2-sided fiberglass);

6. RF connector;

7. open reactive loop.

The shoulders of the vibrator 1 are two rectangular conductors with 90 ° bends towards the passive reflector 2. In the places where the shoulders of the vibrator 1 are bent, matching bevels are introduced at an angle of 45 °. This topology of the vibrator arms is necessary to ensure the expansion of the frequency bandwidth and the increase in the resonant length of the vibrators.

The shoulders of the vibrator 1 have a coupling gap in the middle and are supplied in antiphase according to the top supply circuit through the RF cable 4, laid from the RF connector 6. The RF cable connector 6 is located in the center of the printed circuit board 5 perpendicular to the short-circuited balancing device 3 in the form of a U elbow at the common level passive reflector 2 and serves as a structural element for mechanical mounting of the printed circuit board. Moreover, the RF supply cable 4 is located on the back side of the printed circuit board 5 relative to the balancing device 3.

On the side of the printed circuit board 5, where the RF cable 4 is located perpendicularly and symmetrically to the communication gap between the printed arms of the vibrator 1, an open reactive cable 7 is placed with a communication window towards the vibrator, galvanically connected to the vibrator arms.

On the reverse side of the printed circuit board 5 there is a short-circuited balancing device 3 in the form of a U elbow, made on connected strip lines that are galvanically connected to the printed arms of the vibrator 1. The topology of the short-circuited U elbow is made symmetrically with respect to the axis of symmetry of the vibrator and is horizontally oriented.

For additional protection against moisture on the printed vibrators, thin-walled foam pads (not shown in the figure) can be glued.

The FAR fragment works as follows:

When working at the reception, an incident plane wave induces antiphase voltages of equal amplitude and phase on the shoulders of the vibrators 1, which are supplied to the RF connectors 6 using the elements of the balancing devices 3 and the RF cables 4.

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 and RF cables 4, and then to the half-wave vibrators that form the overall radiation pattern due to the addition of signals in space.

Open reactive loops 7 play the role of tuning elements and allow you to expand the frequency band of conventional vibrators with top power by 2-3 times at the level of K _s 1.5 ÷ 1.6, which ensures the beam swing at angles ± 45 ° in the frequency band 16 ÷ 12 %

In figures 4-12 shows the results of modeling using the HFSS program and prototyping a fragment of the PAR using vibrators in the L range, namely:

In FIG. 4 - shows the radiation pattern of the claimed fragment of the PAR, consisting of a line of 6 vibrators.

In FIG. 5 - shows a three-dimensional radiation pattern of the claimed fragment of the PAR, consisting of a line of 6 vibrators.

In FIG. 6 - shows the simulation of the radiation pattern of a single vibrator in the E plane of the claimed fragment of the PAR.

In FIG. 7 - shows the simulation of the radiation pattern of a single vibrator in the H plane of the claimed fragment of the PAR.

In FIG. 8 - shows the modeling of the SWR of the vibrator in the lattice when the beam is swinging from 0 ° to 45 ° in the H plane of the claimed fragment of the PAR.

In FIG. 9 - shows the modeling of the SWR of the vibrator in the lattice when the beam is swinging from 0 ° to 45 ° in the E plane of the claimed fragment of the PAR.

In FIG. 10 - shows the layout of the SWR of a single vibrator of the claimed fragment of the PAR.

In FIG. 11 - shows the modeling of the SWR of a single vibrator of the claimed fragment of the PAR.

In FIG. 12 - shows the modeling of the SWR vibrator in the lattice of the claimed fragment of the PAR.

In FIG. 13 - shows the layout of the SWR of the claimed fragment of the PAR, consisting of a line of 6 vibrators.

During the tests, the excitation of the PAR element of six elements was carried out through an unfastened in-phase strip divider in 6 directions with a step dy of 120 mm. The 6-way strip decoupled common-mode divider ensured a decrease in the signal level from the central vibrator to the extreme ones - 8 dB.

The main conclusions on the results of prototyping and modeling.

A fragment of the phased arrays of widespread use using printed half-wave vibrators with top power and a modified shape of the topology of the U elbow is proposed, which made it possible to reduce the vertical size of the balancing device.

The simulation confirmed the possibility of the beam swinging in the PAR fragment at angles of ± 45 ° in the frequency band from 1 Hz to 1.65 Hz.

Modeling in the E and H planes confirmed the possibility of forming a symmetrical pattern of the inventive vibrators with a phase center in the middle of the vibrator.

The obtained experimental data on the tests of the claimed fragment of the PAR, consisting of printed vibrators (n = 6) led to the conclusion that the broadband printed half-wave vibrators in the PAR do not require additional tuning.

A new quality has been obtained - the extension of the band of transmitted frequencies to 650 MHz.

A new simple broadband fragment of the phased array was created that meets the high demand for high-frequency parameters: SWR, rolling angles, manufacturability, ease of maintenance, ease of manufacture.

Bibliography:

1. Microwave antennas and devices “Phased array antenna design” edited by D.I. Voskresensky. M. Radio and communications, 1981 pp. 33 rice 210, 211.

2. G.Z. Eisenberg "Antennas of ultrashort waves." - M. "State Publishing House of Literature on Communications and Radio", 1957, p. 262, 263 fig. 13.4.XIII

3. Scanning systems. Microwave part II. Translation from English edited by G.T. Markova and A.F. Chaplin, vol. II, Soviet Radio M, 1969, pp. 459-478.

4. RF patent No. 124516 for utility model, application 2012141983 dated October 2, 2012 “Fragment of a multi-element controlled strip phased antenna array of the L band”, authors Shabalin AV, Vdovin V.E.

Claims (2)

1. A fragment of a multi-element controlled strip phased array antenna (PAR) of the L range, containing a common passive reflector, symmetrical half-wave vibrators and cable RF connectors located along the axis of symmetry of the vibrators at the level of the common passive reflector, which serve as structural elements for mechanical mounting of printed circuit boards, vibrators made on one double-sided printed circuit board and arranged in accordance with the PAR scheme perpendicular to the plane of the common passive reflector, each vibrat p includes two arms that are in the middle of the symmetry axis due gap and energized by radio frequency (RF) cable extending from the RF connector in antiphase upper supply circuit; on one side of the printed circuit board perpendicularly and symmetrically to the communication gap between the printed shoulders of the vibrator there is an open reactive loop with a communication window towards the vibrator, galvanically connected to the shoulders of the vibrator, and also a short-circuited balancing device in the form of a U elbow on connected strip lines, while the distance from the middle of the shoulder of the printed vibrator to the common passive reflector is λav / 4, characterized in that the topology of the short-circuited balancing device in the form of U count The pen is symmetrical with respect to the axis of symmetry of the vibrator and horizontally located, and the RF supply cable is located in the center on the reverse side of the printed vibrator perpendicular to the printed strip conductors of the modified U elbow at the level of the common passive reflector, in addition, to expand the frequency bandwidth and increase the resonant length of the vibrators the topology of the shoulders of the vibrators is made with bends of 90 ° towards the passive reflector and matching bevels are introduced at the bend at an angle of 45 °. 2. Fragment PAR according to claim 1, characterized in that for additional protection against moisture on the vibrators in the field of excitation stick protective elements, such as thin-walled foam pads.

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