RU150630U1 - Fragment of a Broadband Phased Antenna Array in Three Frequency Bands - Google Patents

Abstract

1. A fragment of a broadband phased antenna array in the three frequency ranges L, UHF and VHF, containing symmetrical half-wave strip vibrators arranged on a one-sided or two-sided plane of a common passive reflector arranged in a single line or plane in accordance with a linear or flat headlamp circuit metallized dielectric board, the shoulders of each vibrator are excited in antiphase by symmetrical stripe connected lines of length cav / 4, which are integral my part of the balancing-matching devices, through high-frequency (HF) connectors, on the balancing-matching devices to ensure the adjustment of the vibrators, tuning elements are installed, characterized in that each balancing-matching device is made in the form of a four-wire connected strip line, where the right and left center stripe lines of width W = λav / 40 with a coupling gap along the axis of symmetry of the vibrator S = λav / 40 form a two-wire feeding strip line connected at an angle in its upper part 90 ° to the printed shoulders with a width of W = λsr / 8 half-wave vibrators with a height of H≤1 / 3λsr, and in the lower part - at the level of a common passive reflector with a length of 0.6λsr, width W = 0.035λsr and a thickness of t = 1 mm, the left central stripe the line is shorted to the case of the passive reflector; the right center strip line is electromagnetically coupled to the left center strip line through the core of the RF connector located at the level of the passive reflector, thereby forming a communication gap; the left extreme strip line of width W = W / 2 is located at a distance S = S / 2 from the left

Description

The utility model relates to antenna technology, in particular, to multi-element microwave (UHF) antennas, and can be used as phased antenna arrays (PAR), both independently and as part of complex transceiver systems, television antennas, cellular antennas, etc. .d.

Currently, there is a wide variety of microwave antennas containing ordered emitters, in accordance with one of the well-known geometries of the grid, these or those emitters, all of them depend on the requirements for the PAR, the level of radiated power and, as a rule, for the most part, except for the PAR in the meter wavelength range, headlamps are built on the basis of printing or other technologies that can significantly improve electrical characteristics due to manufacturing accuracy, structural improvements and production technologies, directing They are aimed at reducing the weight of antenna arrays and reducing the cost of their manufacture.

Known linear printed phased array [1], consisting of symmetrical printed semi-wave vibrators located in the same plane above the conductive screen at a distance of a quarter of the average wavelength of the operating range and in-phase excited. The vibrator excitation circuit is made on two connected strip lines with lower excitation.

In this headlamp, the printed arms of the same name as the vibrators have a feeding point from the feeder path, located on the plane of the conducting screen at the base of the vertical printed excitation sections that pass into the arms of the vibrators at a 90 ° angle, and the opposite printed arms of the vibrators are galvanically shorted to the housing of the common screen or reflectors ( meter wavelength range), while adjacent vertical printed sections of the excitation of the same and opposite shoulders of the vibrators are equipped with parallel distribution planes the location of the sections of the supply lines matching capacitive flat conductive elements.

The disadvantage of this technical solution is the relatively narrow band of transmitted frequencies (10-15%).

Closest to the technical nature, i.e. the prototype (see Fig. 1), is a broadband linear multi-element vibrator headlamp [2], containing printed strip half-wave vibrators 1, whose shoulders 1a, 1b are fed through high-frequency (RF) connectors 3 in antiphase, arranged orderly to the plane of the common passive reflector 2 symmetrical stripe connected lines 5, 6, 7, equipped with a balancing-matching devices [3]. Each balancing-matching device is made in the form of a three-wire strip line 5, 6 and 7, formed by two parallel closely spaced narrow slots (coupling gaps) in the metal layer on the same side of the dielectric plate as the shoulders of the strip vibrators 1a, 1b, and the right one the lateral strip line 5 together with the central strip line 6 at a length of a quarter of the average wavelength of the operating range (λav / 4) forms an open reactive loop, the left lateral strip line 7 together with the cent cial stripline 6 to a length of a quarter of the average operating wavelength range, constitutes a symmetrical two-wire line to be connected to the half-wave vibrator shoulders 1a, 1b. Each half-wave vibrator 1 is made on one board and consists of two wide conductors with communication gaps and the shoulders 1a, 1b of each vibrator 1 are symmetrically tapering towards its middle. On the reverse side of the dielectric plate, in the area of the three-wire strip line 5, 6, 7, conductive capacitive tuning elements (tuning elements) 4 are installed.

The disadvantages of this technical solution is that the vibrators, due to the asymmetry of the structure, have a phase center offset and an hour pass band of no more than 40%.

The technical result of the proposed utility model is to significantly expand the bandwidth of the transmitted frequencies with the possibility of realizing half-wave vibrators in the claimed fragment of the PAR in three frequency ranges (L, UHF, VHF). An additional technical result is the lack of the need for additional adjustment of the vibrators after installation in the HEADLIGHT.

The specified technical result is achieved by the fact that in a known fragment of a broadband headlamp that contains orderings placed on the same line or plane in accordance with a scheme, for example, a linear or flat headlamp, perpendicular to the plane of a common passive reflector (or half-wave reflectors lying in the same plane as vibrators), symmetrical half-wave vibrators made on a single or double-sided metallized dielectric board, in which the shoulders of each vibrator are excited in otivophase with symmetrical stripe connected lines of length cf / 4, which are an integral part of a balancing-matching device, through high-frequency connectors, where conductive tuning elements of a capacitive nature (tuning elements) are installed on the balancing-matching device to ensure vibrators are tuned, and matching device is made in the form of a four-wire connected strip line, where the right and left center strip lines of width W ₁ = λc p / 40 with a coupling clearance along the axis of symmetry of the vibrator S = λav / 40, form a two-wire feeding strip line connected in its upper part at an angle of 90 ° to the printed arms of half-wave vibrators with a width of W = λav / 8 and a height of H≤1 / 3λav, and in the lower part at the level of the common passive reflector (length 0.6λср, width Ш ₃ = 0.035λср, thickness t = 1 mm), the left center strip line is shorted, for example, by soldering to the case of a passive reflector, the right center strip line is electromagnetically coupled to left center stripe line h Res central conductor RF connector located at the level of the passive reflector, forming a communication gap left extreme stripline (width W ₂ = W _1/2) is located at a distance S ₁ = S / 2 from the left of the central strip line and electromagnetically with it it is connected, in the lower part the left extreme strip line is shorted to the passive reflector housing, and in the upper part it is open through the communication gap, where together with the left central strip line they form a short-circuited reactive loop, the right extreme strip line (w Rina W _2), located at a distance S ₁ from the right of the central strip line electromagnetically with it is associated and also open at the top (communication gap), and the bottom is shorted to the passive deflector and forms, together with the right central stripline open jet plume; perpendicular to the central strip lines with a communication gap S towards the center lines, tuning elements are installed; after regulation is over, the adjusting elements are fixed on the central strip lines, for example, by soldering.

Each half-wave vibrator of height H≤1 / 3λср is two strip of one-sided or two-sided conductors with a width of Ш ₁ = λср / 40 with a coupling gap along the symmetry axis of the vibrator S = λcp / 40, mounted perpendicular to the passive reflector, the length of which is 0.6λср, and due to its broadband, the vibrators in the headlamp assembly do not require additional adjustment.

The tuning elements are made on the basis of double-sided dielectric metallized plates and are used to ensure the adjustment of vibrators. After the final installation of the tuning elements on the balancing-matching devices, half-wave vibrators do not require additional settings during operation.

The use of two reactive loops (a short-circuited length λср / 4 on the left side of a two-wire spike line and an open loop also λср / 4 on the right side, which are connected in parallel with a two-wire line) as part of the design scheme of half-wave vibrators, can significantly expand the antenna operating frequency band from 40 up to 60% or more.

In the claimed fragment of the broadband phased array, broadband half-wave vibrators are used, the implementation of which is possible in the three frequency ranges L, UHF and VHF.

Perhaps the multifunctional use of these broadband half-wave vibrators as:

- FAR radar;

- receiving television antennas;

- transceiver antennas of cellular communication;

- design schemes for expanding the bandwidth of antennas of the “wave channel” type, which are widely used in meter radars, as well as receiving television antennas for collective use.

Broadband is inherent in the scheme and design of half-wave vibrators and involves tuning them during the debugging period by tuning elements with a communication gap in the direction of the central strip lines, which are installed perpendicular to the central strip lines and, after adjustment, are attached to them, for example, by soldering. After adjustment, the adjustment elements are introduced into the topology of the printed circuit board.

The vibrators are adjusted as follows: first, the lower tuning element is installed without soldering with a known longer electrical length than required, then the upper tuning element is also installed, also with a slightly larger electrical length; the mutual position of the tuning elements is selected and fixed to reduce the SWR in a wide frequency band. Next, the adjustment is carried out after soldering the tuning elements in places of best coordination with the help of these tuning elements. The final setting of the vibrator is carried out by trimming (reducing the electric length) of the tuning elements, which provides the minimum values of Ksv in a wide frequency band.

To illustrate the claimed fragment of the PAR, the following figures are given:

FIG. 1 is a structural diagram of a printed prototype vibrator excited by a three-wire strip line (coplanar waveguide).

FIG. 2 - layout of symmetrical half-wave vibrators of the inventive HEADLIGHTS installed in the corners of a rectangular grid above a common passive reflector (top view).

FIG. 3 is a structural diagram of a printed half-wave vibrator of the claimed fragment of the phased array excited by a four-wire strip line (coplanar waveguide).

FIG. 4 - experimental results for Ksv double-sided half-wave printed vibrator in the L range for the inventive fragment PAR.

FIG. 5 - experimental results on the SWR layout of a single vibrator of the claimed fragment of the PAR in the UHF wavelength range.

FIG. 6 - experimental results on the SWR of the mock vibrator of the claimed fragment of the PAR in the VHF wavelength range.

FIG. 7 - Ksv single vibrator of the claimed fragment of the PAR in the UHF wavelength range (simulation).

FIG. 8 is a three-dimensional diagram of a broadband vibrator in the UHF band (simulation).

FIG. 9 - SWR of a linear antenna with vertical polarization in the UHF band of the infinite array (simulation).

FIG. 10 is a cross section of the radiation pattern in the E plane of a broadband vibrator in the UHF range (simulation) of the claimed fragment of the PAR.

FIG. 11 - SWR layout of a linear antenna with vertical polarization in the L range of six vibrators, with a common reflector.

FIG. 12 is a directivity diagram of a linear antenna with vertical polarization in the L range (prototyping) of six vibrators, with a common reflector of the claimed fragment of the PAR.

A fragment of a broadband headlamp (see Fig. 2) contains a headlamp located in a rectangular grid, at a fixed distance from each other dx and dy at a height of cav / 4 above the plane of a common passive reflector 2 of width W ₃ , symmetrical half-wave strip vibrators 1 perpendicular to it, made in the form of strip conductors on a dielectric plate and powered through RF connectors 3.

In the UHF range (see Fig. 3), the arms 1a, 1b of each symmetrical half-wave vibrator 1 with a height of H = 175 mm are two strip conductors with a width of W = 30 mm with a coupling gap of S = 10 mm between them. To the shoulders of the vibrator 1a, 1b, the right center 6 and left center 7 strip lines with a width of W ₁ = 10 mm are galvanically connected, which are a symmetrical two-wire strip line, which is an integral part of a balancing-matching device.

Each balancing-matching device is made in the form of a four-wire connected strip line - the right extreme 5 (W ₂ = 5 mm), the right central 6 (W ₁ = 10 mm), the left central 7 (W ₁ = 10 mm) and the left extreme 8 ( W ₂ = 5 mm), forming parallel narrow slits with a width of S = 10 mm in the center and S ₁ = 5 mm to the left and to the right of the central gap - communication windows.

The right extreme 5 strip line together with the right central 6 strip line along the length λav / 4 form an open reactive loop with a coupling gap S ₂ = 5 mm; the left extreme 8 strip line together with the left central 7 strip line form a short-circuited reactive loop (the communication gap is also S ₁ ).

To the four-wire strip line 5, 6, 7, 8, the RF signal is supplied from below through the RF connector 3, mounted at the plane of the common passive reflector 2; the central core of the RF connector 3 through the communication gap S ₃ = 1 mm is connected to the right central 6 strip line. Extreme right 5, extreme left 8 and central left 7 strip lines are galvanically shorted at the level of a common passive reflector 2 to the housing of the RF connector 3.

On each side of the dielectric plate, in the communication region of the right central 6 and left central 7 stripe lines, open reactive loops are installed perpendicular to these strips with communication windows S centered in the direction of printed coupled conductors acting as tuning elements 4.

In the proposed fragment of the broadband HEADLIGHTER, the vibrators can be made either metal (VHF range) or printed (L, UHF, VHF ranges) depending on the wavelength range (Fig. 3 is a printed embodiment of vibrators based on metallized fiberglass with a thickness of t = 1 mm in the L range).

A fragment of a broadband flat microwave antenna operating in the PAR mode provides unipolar radiation from strip half-wave vibrators in a wide frequency band in three ranges.

The proposed structural scheme of the half-wave vibrators, from which the claimed fragment of the HEADLIGHTS is formed, allows you to expand the bandwidth of transmitted frequencies to 60% or more (see Fig. 4-6).

According to the results of experimental work with single vibrators manufactured according to this technical solution in three frequency ranges (L, UHF, VHF), as well as the layout of the six-element antenna array (dy / λcp) = 0.5, powered through an in-phase divider in eight directions, obtained performance characteristics (see Fig. 11, 12) confirming the claimed technical result. Namely, the operating frequency band of the proposed antenna fragment reaches 60% in terms of Ksv = 1.8. All vibrators were tuned to the lowest possible SWR at the stand and then installed in the headlamp without any additional settings.

In FIG. Figure 12 shows the generated radiation pattern during excitation of the lattice vibrators (n = 6, d / λcp = 0.5) by an in-phase divider into eight directions with a change in division to the extreme vibrators to -12 dB.

The electrical symmetry of the shoulders of the proposed vibrator is achieved due to the symmetrical topology of the conductors of the coplanar waveguide, while the axial line of the two wire lines must coincide with the axis of symmetry of the vibrator.

The simulation results on a personal electronic computer in the Microvawe Offis system showed that the radiation pattern of the proposed antenna is symmetrical and, therefore, the phase center coincides with the axis of symmetry of the vibrator. The results were obtained when using fiberglass with a thickness of t = 1.0 mm; on the central strip lines 6, 7, capacitive tuning elements were installed, which are included in the topology of the printed circuit board of a half-wave vibrator.

The proposed technical solution makes it possible to connect coplanar waveguides to the shoulders of the vibrators and to the feeding feeder lines, which can be either symmetrical or non-symmetrical strip lines.

As you know, non-symmetrical lines are widely used in view of their manufacturability, which is important in serial production, but non-symmetrical strip lines have large losses, are poorly protected from external interference on the excitation circuit. The use of symmetrical strip lines gives a gain in reducing microwave losses in the excitation circuits, as well as symmetrical strip lines provide excitation circuits without possible interference due to the complete shielding of the microwave field inside the line.

The experimental data obtained in the L and UHF ranges (prototyping, modeling) made it possible in a simple way - by recalculating from the L range in UHF and VHF, to obtain data on the size of the vibrators in the indicated ranges. The results obtained on the mock-ups are shown in FIG. 4, FIG. 5 and FIG. 6, where it can be seen that the bandwidth of the transmitted frequencies is at least 60%.

The mechanism for expanding the passband of half-wave symmetric vibrators excited by four-wire balancing-matching devices on connected lines is based on mutual compensation of the reactive components of the input impedance of the vibrators of the two-wire stripe symmetrical line, electromagnetically coupled to two reactive loops having opposite values of the reactive components of the input resistance, as well as tuning two-wire capacitive elements supplies power to the strip line length λsr / 4 and forming an integral part of the vibrator topology.

All of the above suggests that the claimed fragment of a broadband phased array using broadband half-wave vibrators with lower excitation in three frequency ranges (L, UHF and VHF), provides high performance in a wide frequency range.

List of references

1 Patent No. 2264009, IPC H01Q 21/08, authors Anurin A.A., Shabalin A.V.

2 Patent No. 90265, IPC H01Q 1/38, authors Shabalin A.V., Tuzaev I.N.

3 Scanning antenna systems microwave part 2 - translation from English edited by G.T. Markova, A.F. Chaplin - M. Soviet Radio, 1969, from 459-478.

4 G.Z. Eisenberg - antennas of ultrashort waves - M. "State Publishing House of Literature on Radio and Communications", 1957, p. 262, 263, fig. 13.1 XIII.

Claims (2)

1. A fragment of a broadband phased antenna array in the three frequency ranges L, UHF and VHF, containing symmetrical half-wave strip vibrators arranged on a one-sided or two-sided plane of a common passive reflector arranged in a single line or plane in accordance with a linear or flat headlamp circuit metallized dielectric board, the shoulders of each vibrator are excited in antiphase by symmetrical stripe connected lines of length cav / 4, which are integral my part of the balancing-matching devices, through high-frequency (HF) connectors, on the balancing-matching devices to ensure the adjustment of the vibrators, tuning elements are installed, characterized in that each balancing-matching device is made in the form of a four-wire connected strip line, where the right and left center stripe lines of width W ₁ = λav / 40 with a coupling gap along the axis of symmetry of the vibrator S = λav / 40 form a two-wire feeding strip line connected at an angle to its upper part m 90 ° to the printed arms with a width of W = λav / 8 half-wave vibrators of a height H≤1 / 3λav, and in the lower part - at the level of a common passive reflector with a length of 0.6λav, a width of W ₃ = 0.035λav and a thickness of t = 1 mm, left the center strip line is shorted to the passive reflector housing; the right center strip line is electromagnetically coupled to the left center strip line through the core of the RF connector located at the level of the passive reflector, thereby forming a communication gap; the left extreme strip line of width W ₂ = W _1/2 is located at a distance S ₁ = S / 2 from the left central strip line and is electromagnetically connected to it, in the lower part the left extreme strip line is shorted to the passive reflector housing, and in the upper part it is open through the communication gap S ₂ = Ш ₂ , where together with the left center stripe line form a short-circuited reactive loop; the right extreme strip line with a width of Ш ₂ is located at a distance S ₁ from the right central strip line, is electromagnetically connected to it and is also open in the upper part, forming a coupling gap S ₂ , and in the lower one is shorted to a passive reflector and forms together with the right central strip line open reactive loop; from either side of the dielectric board, perpendicular to the central strip lines with a communication gap S towards the central strips, tuning elements are installed, after adjustment is complete, the tuning elements are fixed on the central strip lines. 2. A fragment of the antenna according to claim 1, characterized in that in the VHF range the half-wave vibrators are made of metal.

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