RU2802177C1 - Vibrator antenna system - Google Patents

Abstract

FIELD: antenna systems.

SUBSTANCE: printed vibrator antenna system contains a rectangular dielectric substrate 1 with front 2 and back 3 surfaces, having a pair of large 4, 5 and a pair of small 6, 7 sides. On the front surface 2, parallel to the large side 4, in close proximity to it, two identical elongated narrow conductors are made, divided in the middle by gaps 8 into two coaxial halves 9, 10 and 11, 12 with adjacent 13, 14 and 15, 16, as well as remote 17, 18 and 19, 20 ends. In this case, the orientation of the halves 9, 10 and 11, 12 on the common axis is opposite. Near the other large side 5, three identical two-channel equal-amplitude power distributors are made without ballast resistors, connected to each other according to an aluminum alloy herringbone ladder, forming a 4-channel common-mode power divider. The divider input is located on the large side 5 and is the input of the antenna system. Two spaced apart outputs 28 and 32 of the divider are connected to adjacent ends 16 and 13 of halves 12 and 9 via two identical two-stage segments of transmission lines 30 and 34, respectively. Two adjacent outputs 29 and 33 of the divider are connected by similar two-stage segments 31, 35 with adjacent distant ends 19 and 18 of halves 11 and 10, respectively.

EFFECT: creation of a more compact and advanced printed linearly polarized vibrator antenna system with a differential radiation pattern having a pronounced saddle in the direction perpendicular to the end of the large side.

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Description

The proposed vibrator antenna system (VAS) belongs to the field of microwave radio engineering and can be used in radar and radio navigation systems for various purposes to determine the direction to the direction-finding object according to the differential radiation pattern, the minimum of which is close to zero lies on one straight line connecting radar with direction finding object. The relevance of improving such AAS is due to the ever-increasing requirements for direction-finding radio engineering systems in terms of their dimensions and weight, reliability, as well as the need to increase the level of production and operational manufacturability.

BAC is known, described March 29, 1988 in US patent No. 4734700 under the name "Group antenna with electronically phase-controlled beam". According to the Abstract, this patent proposes to implement in an imaginary three-dimensional volume [for example, in a volume in the form of a sphere - see Fig. 5 of the full Description of this patent] eight areas with adjacent boundaries containing a plurality of individual emitters fed by microwave transmission lines. After the arrangement and necessary electrical connections of these emitters and auxiliary elements, this antenna system generates a sum signal, one elevation difference signal and two azimuth difference signals used for target radar and its tracking when moving. As follows from the full Description of this patent, the outputs of the channels with the above signals, as well as the auxiliary non-operating outputs of the BAC, are connected to matched loads to avoid electromagnetic reflections [see. column 1, lines 56 - 66 of the Description]. In this case, in-phase-anti-phase ring power dividers are used as auxiliary elements [see. figures 7 - 12 of the Description], and you can also use double waveguide tees (magic T) [see. column 1, lines 45 - 50 of the Description]. In the process of building this VAS in coaxial, stripline or waveguide versions, numerous transmission line intersections occur, which should be properly implemented [see. column 2, lines 9 - 49 Descriptions].

As a proposed technical embodiment of this VAS, it is recommended to use horizontally polarized loop or dipole (in other words, vibrator) emitters [see. column 5, lines 31-42, and figure 5 of the Description]. At the same time, the confidence is emphasized that with such emitters the signals necessary for direction finding will be properly formed [see. multi-step claims of this patent].

However, the practical implementation of three-dimensional structures in the microwave range is inevitably limited by the requirements of a high-quality and reliable electrical connection of all emitters and auxiliary elements to each other, if necessary, to ensure the required relative position of the latter in the layout space. This circumstance determines the desire to achieve the highest possible production and operational manufacturability of microwave products. And in this regard, the described waveguide implementation of the VAS does not allow significant progress towards achieving the miniaturization and manufacturability indicators required today.

Also known is BAC, described April 12, 1994 in US patent No. 5302961 under the name "Antenna aperture with main lobe jammer nulling capability". From the Abstract of this patent, it follows that it provides a non-rectangular antenna aperture containing four rectangular areas for receiving electromagnetic signals. At the same time, the ability to form in the surrounding space the prescribed total beam (total radiation pattern), the first and second difference beams, and also the double difference beam is implemented, so that the product of the first and second difference beams is equal to the product of the total and double difference beams. This ability is ensured by the use of properly connected classic basic elements in this device, such as: waveguides, amplifiers, attenuators, transceiver modules, double waveguide tees (in other words: the magic "T") [see. column 3, lines 48-60, and also column 16, lines 2-14 of US Pat. No. 5,302,961]. Vibrator (dipole) elements are also involved there [see. column 7, lines 5-18, and also column 15, lines 10-16 of the Description]. At the same time, it is indicated that this system can be used both for receiving and transmitting probing radio signals [see. column 4, lines 31-53 of the Description].

As a result, the described VAS, with an appropriate design, forms difference beams in the surrounding space as with unequal ones [see Fig. figures 4b, 4c, 4d Description], and with almost identical [see. Figures 4f, 4g Description] side lobes, which can be used to solve the problems of direction finding and radar.

However, the waveguide design of the VAS elements, including vibrator radiators, leads to very bulky structures, which are very time consuming to assemble and adjust and are accompanied by significant expenditures of effort and money.

Thus, the three-dimensional vibrator antenna system described in the US patent does not meet modern requirements for operational manufacturability due to the complexity of assembly, significant dimensions, weight and cost of the product, as well as its reliability due to the large number of waveguide flanges connected by screws with nuts.

An antenna system is also known, which, when using half-wave vibrators, can be called the "Vibrator Antenna System" (VAS), described November 10, 1992 in US patent No. 5162804 under the name "Amplitude distributed scanning switch system". In this system, several independent of each other (that is, decoupled by the corresponding inputs of the device) directional patterns (beams), including the spacing pattern, are formed. The block diagram of this system is based on the classic 8-beam Butler matrix, supplemented by an ensemble of auxiliary microwave power dividers and phase shifters [see Fig. figure 1 of the Description of this patent]. In accordance with this block diagram, the beamforming algorithms are described under the condition of using a circular phased array antenna with eight radiators [see. figure 5 of the Description]. Any recommendations about the specific design of these emitters [items 201 - 208 in figure 5] in the patent is not given. Apparently, they can be any suitable for solving radio direction finding problems. The Applicant believes that these can also be vibrator/dipole emitters, including their printed version on foil sheet organic dielectrics.

In the process of describing the principle of operation of this VAS, a mechanism was substantiated for the formation of a differential radiation pattern (beam) with a signal minimum lying in the corresponding direction to the target [see. column 5, lines 12-17 of the Description] with an attenuation level of about 12 dB from the peaks [see figure 7 of the Description].

However, in the practical implementation of the described VAS, it is hardly advisable to use standard rectangular waveguides, since both the Butler matrix and the circular antenna array in the waveguide design are very bulky and are characterized by an insufficient level of production and operational manufacturability. If, however, printed strip or microstrip versions of elements and emitters are used, then to assemble the entire VAS, connecting coaxial cables (there must be at least eight of them) between the outputs of a planar printed 8-beam Butler matrix and the inputs of the emitters of an 8-element three-dimensional circular antenna array will inevitably be required. The presence of such cables does not allow to provide a high level of radio direction finding reliability in terms of a minimum differential radiation pattern and operational manufacturability.

The prototype of the proposed invention is the vibrator antenna described on September 27, 2015 in the patent of the Russian Federation No. 2571156. This antenna can be considered as a special case of the simplest vibrator antenna system (VAS), which contains one half-wave vibrator and one equal-amplitude quadrature microwave power distributor. If the electrical connections are made according to the Claims of this patent, then the maximum of the antenna pattern is deviated by 20 degrees from the direction perpendicular to the center line of both halves of the half-wave vibrator [see. figure 7 of the Description].

However, the shape of the radiation pattern in the yoz plane of the electric vector E [see Figures 2, 4 and 7 of the Description] has the form of a “figure eight”, the axis of which is deflected by 20 degrees from the perpendicular to the aforementioned axial line of both halves of the dipole.

Thus, this simple VAS does not provide the formation of a radiation pattern with a sufficiently deep minimum/saddle in the direction of the difference signal and cannot be used for radio direction finding.

The objective (technical result) of the invention is to create a more compact and technologically advanced printed vibrator antenna system with a differential radiation pattern, the minima of which are pronounced and located in a plane perpendicular to both the vibrator centerline and the substrate plane.

The solution of this problem is ensured by the fact that in a well-known vibrator antenna system containing an elongated narrow conductor with a small cross section, divided in the middle by a gap into two halves with adjacent and distant ends relative to each other,

two-channel equal-amplitude power distributor, one of the outputs of which is connected to the adjacent end of one of the halves of the conductor, and its second output is connected to the remote end of the other half of the conductor by identical segments of transmission lines, an identical narrow conductor with two halves and corresponding ends is additionally introduced, the first and second are similar power distributors, the first pair of identical sections of transmission lines, as well as the second pair of single-stage sections of transmission lines, the length of which is the same, but arbitrary, while both elongated narrow conductors with two halves each are located coaxially on a common axis, and the orientation of the narrow conductors on this axis is opposite , wherein the first additionally introduced power distributor is connected to the adjacent and remote ends of the additionally introduced narrow conductor by the first additionally introduced pair of identical sections of transmission lines, two outputs of the second additionally introduced power distributor are connected to the inputs of the two previous distributors by the second additionally introduced pair of single-stage sections of transmission lines, and the input of this distributor is the input of the vibrator antenna system, all three power distributors are made in-phase, and identical segments of transmission lines are implemented as two-stage.

Figure 1 shows a structural layout diagram of a vibrator antenna system, created on the basis of the topology of its printed circuit board, in Fig. 2 shows a fragment of the topology of the front side of the BAC printed circuit board, in Fig. 3 shows the combined topologies of the front and back sides of the printed circuit board BAC, in Fig. 4 shows the same co-located topologies with directions of the respective currents, FIG. 5 shows the theoretical frequency response of the reflectance modulus and measurement results, FIG. 6 shows the theoretical radiation pattern of the EAC and the results of the experiment.

The proposed vibrator antenna system (Fig. 1) contains a thin rectangular dielectric substrate 1 with a thickness H with front 2 and back 3 surfaces, having a pair of large 4, 5 and a pair of small 6, 7 sides. On the front surface 2 parallel to the large side 4 at a short distance two identical elongated narrow conductors with a small cross section are made from it, separated in the middle by gaps 8 in length into two halves formed by conductors 9, 10 and 11, 12, respectively. In this case, the left (in Fig. 1) elongated narrow conductor was present in the prototype, and the right elongated narrow conductor is additionally introduced according to the Claims of the present invention. The conductors of each of the four halves have adjacent 13, 14 and 15, 16 ends. The same conductors 9, 10 and 11, 12 also have ends 17, 18 and 19, 20 remote with respect to adjacent ones. In this case, all conductors 9, 10, 11 and 12 (in other words: all four halves) have the same length and width . They are formed on the front surface 2 of a double-sided foil initially dielectric substrate 1 by technological methods of photolithography and selective/selective etching of copper foil with a thickness from gaps (see the work: Bushminsky I.P., Morozov G.V., “Technological design of microwave microcircuits”, - M .: Publishing House of the Moscow State Technical University named after N.E. Bauman, 2001, 356 pp.: ill .). As a rule, the thickness of copper foil for domestic foil dielectrics is 35 micrometers: = 0.035 mm. At the same time, the distance , which characterizes the edge technological fields both along the large 4, 5, and along the small 6, 7 sides and the nearest edges of the printed foil conductors of any conductive fragments, is assigned in the domestic design and technological documentation within 0.2 - 0.5 mm: = 0.2…0.5 mm. In the same documentation and the aforementioned work, I.P. Bushminsky, G.V. Morozov width of conductors 9, 10, 11 and 12 is assigned based on the adhesive properties of foil dielectrics, and has a minimum value within 1.0 - 1.5 mm: = 1.0…1.5 mm. At the same time, both of the above-mentioned elongated narrow conductors with two halves 9, 10 and 11, 12 are each located coaxially on a common axis "a" - "a" and are separated from each other by a distance order (3 – 5) of the substrate thickness. As a result, the distance between the remote end 18 of the conductive half 10, related to the left (Fig. 1) elongated narrow conductor, and the remote end 19 of the conductive half 11, related to the right elongated narrow conductor, will be = (3…5) N .

Three identical two-channel equal-amplitude in-phase power distributors are also made on the front surface 2 of the substrate 1 (Fig. 1). At the same time, the upper left distributor was present in the prototype, and the upper right and central lower distributors were additionally introduced according to the Formula of the present invention, and the input 21 of the central lower distributor is the input of the entire proposed EAC. The end of the printed conductor of this input is separated from the large side 5 of the substrate 1 by the value of the width edge technological field. Two outputs 22, 23 of the second additionally introduced power distributor, which is also the central lower distributor (Fig. 1), are connected to the inputs 24, 25 of the two previous left and right distributors of the second additionally introduced pair of single-stage segments of transmission lines 26, 27, the length of which is the same, but arbitrary.

In turn, the outputs 28, 29 of the first additionally introduced power distributor, which is the upper right distributor (Fig. 1), are connected respectively to the adjacent 16 and remote 19 ends of the halves 12 and 11 of the additionally introduced narrow elongated conductor, which is in Fig. 1 right narrow elongated conductor. The connection is made by the first additionally introduced pair of identical two-stage sections of transmission lines 30 and 31. At the same time, two outputs 32, 33 of the left upper power distributor are connected, respectively, to the adjacent 13 and remote 18 ends of the halves 9 and 10 of the first narrow elongated conductor, which is in Fig. 1 left narrow elongated conductor. The connection is made using a pair of identical two-stage transmission line segments 34, 35. As a result, the two-stage segments 30, 31, 34 and 35 are identical and have a length each section, as well as the widths And narrow and wide sections, respectively. In this case, the orientation of narrow elongated conductors, divided by two gaps 8 into two halves each, is opposite on the axis "a" - "a" (Fig. 1), and all three identical two-channel equal-amplitude common-mode power distributors and an additionally introduced pair of single-stage segments of connecting transmission lines 26, 27 between them are characterized by different widths of printed conductors And indicated on a separate printed fragment of the claimed BAC (Fig. 2, gray color).

Thus, on the front surface 2 of the substrate 1, conductive printed fragments (Fig. 1, light gray) are formed, which are under the power potential of the generator of the emitted signal, supplied by a 50-ohm coaxial cable to the VAC input 21. To connect the cable on the large side 5 of the substrate 1, a small-sized coaxial-microstrip connector/connector of the SMA type is provided, the central pin of which is galvanically (for example, soldered) connected to the printed conductor of the input 21 (the connector is conventionally not shown in Fig. 1).

The taps of the connector housing are also galvanically connected to a large printed grounded conductor 36, implemented on the reverse side 3 of the dielectric substrate 1 (Fig. 1, dark gray). On the same side, 4 printed identical rectangular pedestals 37, 38, 39 and 40 with dimensions , the upper (in Fig. 1) bases of which are continuations of the grounded conductor 36. The pedestals are located under the wide transmission lines of two-stage identical segments 30, 31, 34 and 35 (Fig. 1) for the entire length wide lines so that the vertical axes of the pedestals coincide with the vertical axes of the wide transmission lines, namely: pedestal 37 is located under the wide line of the two-stage segment 30, pedestal 38 - under the wide line of segment 31, pedestal 39 - under the wide line of segment 35, pedestal 40 - under the broad line segment 34. This circumstance is illustrated in FIG. 3, which shows the claimed BAC with combined conductive fragments of both sides 2 and 3 of substrate 1 (fragments of the front side 2 are light gray, grounded fragments of the reverse side 3 are dark gray).

The principle of operation of the proposed EAC is as follows.

Let to input 21 through coaxial cable with characteristic impedance 50 ohms from a generator with internal real resistance (in Fig. 1, the generator, cable and coaxial-microstrip connector are conventionally not shown) a harmonic microwave signal is supplied, the amplitude of which remains unchanged in the frequency band from the lower and top borders at the center frequency . The voltage of the applied signal by three common-mode equal-amplitude power distributors connected to each other according to the “herringbone” scheme is divided by the frequency into four equal parts. At the same time, the width And strip lines shown in Fig. 2, should be calculated according to a well-known method (see, for example, the work: "Handbook of the elements of strip technology" / Edited by A. L. Feldstein. - M .: Svyaz, 1979, section 6.3, Fig. 6.12), in which the final stage is modified by the fact that ballast resistors are not used in all three distributors in order to simplify the implementation technology. The latter is permissible, since both emitters of the proposed EAC, formed by two elongated narrow conductors, divided in the middle by gaps 8 into two halves 9, 10 and 11, 12 (Fig. 1), are emitters described in the prototype and characterized by a relative operating frequency band of the order ( 4…6)%. In fact, the claimed BAS uses two dipole-type emitters, in which common-mode excitation voltages come from the outputs 28, 29 and 32, 33 of the distributors to one adjacent and one remote arm/end in the right and left emitters (Fig. 1) respectively. At the same time, unlike the prototype, all three power distributors are in-phase, and identical segments of transmission lines 30, 31, 34 and 35, although they are implemented as two-stage, they do not distort the in-phase excitation voltage at the ends 13, 18 and 16, 19, carrying out only the transformation of high values of the real part of the input resistance (of the order of 550 ... 750 Ohms) described in the prototype of the dipole type emitter with center-end power to the level of wave impedance = 71 Ohm microstrip lines common-mode outputs 28, 29 and 32, 33 top (in Fig. 1) identical power distributors. At the same time, the wave resistance And , the values of which are necessary for calculating the widths And stages of two-stage segments of transmission lines 30, 31, 34 and 35 (Fig. 1) are determined by the classical method for designing two-stage / two-section impedance transformers, described, for example, in the work: “Microwave Devices and Antennas” /Ed. D. I. Voskresensky. - M .: Radio engineering, 2016, section 4.3, fig. 4.10.

As a result of in-phase power, both the left and right (Fig. 1) dipole-type emitters with radiating halves 9, 10 and 11, 12, respectively, would form, being solitary, in the surrounding free space, two radiation patterns, the maxima of which would be oriented in positive axis direction (that is, in the direction of the ortho ). In the opposite direction (orth ) each of the two radiation patterns is characterized by values 15 ... 18 decibels less than the values in the positive direction of the axis (ort ). This is due to the significant influence of an extensive grounded printed fragment 36 implemented behind the emitters on the reverse side 3 of the substrate 1 and connected to the grounded metal case of the coaxial microstrip connector. This fragment, together with pedestals 37, 38, 39 and 40, is required as a return conductor of microstrip lines of all three two-channel equal-amplitude common-mode distributors and four identical segments 30, 31, 34 and 35 of connecting transmission lines implemented as two-stage (Fig. 1).

As a result, currents , , And output ends of wide microstrip lines with a size identical two-stage transmission lines 30, 31, 34 and 35 are in-phase and equal amplitude: . Their directions at some point in time are shown in Fig. 4. These currents, leaving wide sections of microstrip lines with reverse grounded conductors in the form of pedestals 37, 38, 39 and 40, on the basis of the law of continuity of the total current, lead to the appearance and maintenance of surface conduction currents , , And , which will carry the unshielded halves 9, 10, 11 and 12 of both elongated narrow conductors with a small cross section (Fig. 4). It is these in-phase and equal-amplitude surface conduction currents are sources of electromagnetic radiation into the surrounding free space. In fact, according to the recommendations of the work of G. T. Markov, D. M. Sazonov "Antennas", M .: Energia, 1975. - 528 p., The mentioned surface conduction currents on halves 9, 10, 11 and 12 can be considered "filamentous" , that is, localized along the longitudinal axis "a" - "a". Time-varying "filamentous" harmonic high-frequency conduction currents flowing over the surface of unshielded halves 9, 10, 11 and 12, according to the equations of D.K. Maxwell, inevitably lead to the emergence and maintenance of time-varying electromagnetic fields in the surrounding space. These fields, interfering in the far Fraunhofer zone, form in this zone the final electromagnetic radiation of the entire claimed VAS.

At the same time, on the common axis "a" - "a", the orientation of the first (left) narrow elongated conductor in figures 1 and 4, divided by a gap 8 into two halves 9 and 10, is opposite to the orientation of the second (right) identical narrow elongated conductor, divided by a similar gap 8 into two halves 11 and 12. Therefore, despite the in-phase nature of the "filamentous" surface conduction currents in time , , And , their directions (in other words: spatial orientation) are pairwise opposite. In other words, currents And co-directed, in-phase in time and equal in amplitude. Currents are similarly characterized And . But the first pair of currents at some point in time flows to the left, and the second pair of currents, being in-phase in time (in other words: being synchronized in time) with the first pair, at the same time flows to the right of the vertical axis claimed BAC (Fig. 4). Meanwhile, according to the materials of the above-mentioned work by G. T. Markov, D. M. Sazonov, electromagnetic interference processes in the far Fraunhofer zone depend not only on the amplitudes and phases of the “filamentous” surface conduction currents, but also on the spatial orientation of these currents, which, in turn, is determined by the configuration of the topology of the conductive layers/patterns of the front 2 and back 3 surfaces of the substrate 1 (Fig. 1).

As a result, the above circumstances lead to the disappearance (in practical implementation: to a pronounced weakening) of the electromagnetic field at points of the far Fraunhofer zone lying in the plane passing through the axis perpendicular to the plane of the substrate 1, which corresponds to the azimuthal angle (measured from the axis in axis direction ) equal to or . When changing the angle in one direction or another, the intensity of the EAS radiation begins to increase. However, the radiation intensity also depends on the elevation angle , counted from the positive direction of the axis to the negative. It is advisable to quantify the radiation intensity using the three-dimensional electromagnetic modeling system “CST Studio Suite”, a perpetual license for the use of which was acquired by the Applicant in 2019. Due to the use of the built-in optimizer of this system, it is possible to select the geometric dimensions of the topology (in other words: adjust the VAC) in order to achieve its high-quality coordination with the signal generator. The optimization results will also be used further in the manufacture of a prototype, which will significantly reduce the amount of work and cost of funds for the experimental development of the VAS.

Thus, with the correct setting of the BAC, that is, with the appropriate calculation of the width of the strip conductors and the verified implementation of the uniformity of the corresponding lengths, a pronounced minimum of electromagnetic radiation occurs at the points of the plane . However, in the plane electric vector the radiation pattern has a pronounced minimum (saddle) and is characterized by a two-peak shape. The extremes of this chart are off axis both sides at the corner , the value of which is determined at a specific frequency by the nature of the interference process in the far Fraunhofer zone. Despite the formation of a saddle in the radiation pattern, the coordination of the VAS with the generator is preserved, since the saddle is not due to the effects of the reflection of high-frequency currents/voltages from the elements of the printed topology, but to the mutual compensation of the electromagnetic fields radiated by halves 9, 10 and 11, 12 (Fig. 1) in points of the far Fraunhofer zone lying in the plane . In other words, in the topology of the proposed VAS, there are no fragments with band-blocking properties, due to which a significant level of reflections of high-frequency currents / voltages back to the signal source connected to the VAS input 21 would be observed.

The specific dimensions of the geometric dimensions of the topology of the proposed printed HAS (in other words: its adjustment as a whole) are found as a result of the correct calculation of the key geometric dimensions using the above literature, thereby creating the initial / starting shape of the HAS for subsequent optimization of these initial dimensions by the non-linear optimizer of the “CST Studio” system Suite". In this case, it is possible to take into account dissipative losses in thin foil conductors of fragments of both sides 2 and 3 of substrate 1 (Fig. 1), as well as losses in its dielectric material. In addition, full-wave 3D modeling and optimization in the “CST Studio Suite” makes it possible to take into account the effects of reflection (albeit small) from the bends of printed strip lines and jumps in their geometric dimensions at the junctions of the strips, as well as to introduce into the analysis the calculation of the influence of higher types of waves (by other words: take into account the multimode structure of local electromagnetic fields), which arise (although they quickly decay with distance from the place of origin) in the transition regions from asymmetric microstrip lines of width to absolutely unshielded radiating halves 9, 10, 11 and 12 wide each (Fig. 1).

As a result of finding the optimal set of geometric dimensions (in other words: settings), the proposed BAC when using foil fiberglass FR-4 ( = 4.58; manufacturer: Electroconnect LLC, 630090, Novosibirsk, st. Engineering, house 4) thick = 1 mm is characterized for wave impedance = 50 ohms and center frequency = 2.8 GHz with the following key dimensions indicated in figures 1 and 2 and mentioned above in the text of the Description (in millimeters):

The same figures also indicate additional parameters that form a complete idea of the dimensions (in millimeters) of the topology proposed by the BAC, and in lowercase letters " » with indices indicate additional dimensions of the front side 2 of the substrate 1, and lowercase letters « "- back side 3 (figures 1 and 2):

The combination of these dimensions ensures good matching between the VAS and the generator, which follows from the frequency response of the input reflectance modulus of the optimized/tuned antenna (Fig. 5, position 41, the solid curve is the theoretical value). This confirms the validity of the interference mechanism in the far Fraunhofer zone of electromagnetic fields of "filamentous" surface conduction currents , , And , which carry the radiating halves 9, 10, 11 and 12 of both identical elongated narrow conductors with a small cross section, separated in the middle by gaps 8 with a size (Fig. 1).

For experimental confirmation of the results of solving the problem, a prototype of the proposed VAS was made with the above geometric dimensions and powered by a coaxial cable RK 50-1-11 ( = 50 Ohm), and the dimensions of the substrate 1 (Fig. 1) were:

- length of large sides 4 and 5: 96 mm;

- length of small sides 6 and 7: 25 mm.

The matching of the BAC to the generator was verified in an anechoic chamber using a Rohde & Schwarz RS-ZVL-13 vector network analyzer and is shown in FIG. 5 points at 42 positions. Radiation pattern (in terms of gain) was measured using conventional far-field Fraunhofer method using standard calibration and measurements using a linearly polarized feed horn, E8257D PSG signal generator, and azimuth and elevation rotators with setpoint accuracy corners . Measurement results for plane electric vector shown in Fig. 6 dots at positions 43. Also shown for comparison is the radiation pattern calculated in the CST Studio Suite system (solid curve at position 44).

Thus, the presented results testify to the solution of the task: the creation of a more compact and technologically advanced printed vibrator antenna system with a differential radiation pattern, the minima of which are pronounced and located in a plane perpendicular to both the axial line of the vibrators and the substrate plane. In a practically implemented printed VAS, the minimum value of the radiation pattern in its saddle differs from the maximum values of the pattern by 19 decibels.

These circumstances together make it possible to recommend the proposed vibrator antenna system for use in stationary and mobile radar and radio navigation systems for various purposes to determine the direction to the direction-finding object using a linearly polarized difference radiation pattern, when systems are subject to increased (more stringent) requirements for the difference in the maximum values of the diagram direction from the value in its saddle.

Claims (1)

Vibrator antenna system containing an elongated narrow conductor with a small cross section, divided in the middle by a gap into two halves with adjacent and distant ends relative to each other, a two-channel equal-amplitude power distributor, one of the outputs of which is connected to the adjacent end of one of the halves of the conductor, and its second output is connected to the remote end of the other half of the conductor by identical segments of transmission lines, characterized in that an identical narrow conductor with two halves and corresponding ends is additionally introduced into it, the first and second similar power distributors, the first pair of identical segments of transmission lines, as well as the second a pair of single-stage segments of transmission lines, the length of which is the same, but arbitrary, while both elongated narrow conductors with two halves each are located coaxially on a common axis, and the orientation of the narrow conductors on this axis is opposite, while the first additionally introduced power distributor is connected to an adjacent and remote by the ends of the additionally introduced narrow conductor by the first additionally introduced pair of identical segments of transmission lines, two outputs of the second additionally introduced power distributor are connected to the inputs of the two previous distributors by the second additionally introduced pair of single-stage segments of transmission lines, and the input of this distributor is the input of the vibrator antenna system, all three power distributors are made in-phase, and identical segments of transmission lines are implemented as two-stage.