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WO2012131126A1 - Daisy antenna for the emission and reception of linearly and circularly polarized electromagnetic waves - Google Patents

Daisy antenna for the emission and reception of linearly and circularly polarized electromagnetic waves

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Publication number
WO2012131126A1
WO2012131126A1 PCT/ES2012/070123 ES2012070123W WO2012131126A1 WO 2012131126 A1 WO2012131126 A1 WO 2012131126A1 ES 2012070123 W ES2012070123 W ES 2012070123W WO 2012131126 A1 WO2012131126 A1 WO 2012131126A1
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WO
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Patent type
Prior art keywords
antenna
petals
daisy
figure
shows
Prior art date
Application number
PCT/ES2012/070123
Other languages
Spanish (es)
French (fr)
Inventor
FOYO Juan LLABRES
Sanz Juan Vassal'lo
Tortajada Jorge Caravantes
SÁNCHEZ Ángel MEDIAVILLA
PUENTE Antonio TAZÓN
Original Assignee
Consejo Superior De Investigaciones Científicas (Csic)
Universidad De Cantabria
Universidad Complutense De Madrid
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Classifications

    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01QAERIALS
    • H01Q21/00Aerial arrays or systems
    • H01Q21/24Combinations of aerial elements or aerial units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01QAERIALS
    • H01Q21/00Aerial arrays or systems
    • H01Q21/24Combinations of aerial elements or aerial units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction
    • H01Q21/26Turnstile or like aerials comprising arrangements of three or more elongated elements disposed radially and symmetrically in a horizontal plane about a common centre

Abstract

The invention relates to an antenna formed by the coplanar grouping of an even number of radiating wires which together form a shape similar to the petal distribution of a daisy (see figure 1). The radiating wires or petals of the daisy antenna work by resonance and have a flat geometry, as well as all having the same structure and being in the same plane, referred to as the antenna plane. The only difference between the petals is in the relative distribution of the current flow directions, which determines the form of the radiation diagram and characterizes the behavior of the antenna, in order to allow users a wide range of applications.

Description

ANTENNA FOR ISSUANCE MARGARITA AND RECEIVING linear polarized electromagnetic waves circularly FIELD OF THE INVENTION

The present invention belongs to the transmitting antennas and / or receiver of electromagnetic signals sector and more specifically relates to the following sub-sectors of technology antennas: antenna broadband electric and magnetic dipoles, radiant transmission systems and receiving antennas for communication systems, antennas for television signal receivers, antennas low cost and visual impact antennas for observing and monitoring systems, and antennas for inhibitors frequency systems.

STATE OF THE ART An antenna is an element or designed and manufactured to receive or emit electromagnetic waves (EM) system. From an elementary view broadcast it is to transform a difference of electric potential varying in time applied to the metal frame of the system in a train of EM waves to propagate by which free space around. The opposite is the reception of EM waves. There are various forms and appearances of antennas, the simplest and best known is the dipole to capture the television broadcast terrestrial, the most complicated can be any of the large paraboloid employees on radio astronomy to capture extremely weak signals coming from the ends of the universe. Different designs, and therefore their technical characteristics depend on the particular application to which they are to be reserved. The shape and the technical concept faces are determining factors in the operating results of the antenna. In basic terms in excess, all lies in comparing the geometric dimensions of the emitter or receiver element and the wavelength to emit or capture. On one hand, demand that make markets for new techniques for both domain emission of radio waves and, equally, on TV, as well as in the security sector, has been demanding for some time now new increasingly complex antenna designs to cover a number of new applications.

Develop the basic ideas are presented in the book "Antennas: Theory and Practice" by Schelkunoff SA and HT Friis, published by Bell Telephone Laboratories, Inc., LCCCN 52-5083, 1952, and in the article "Ultrahigh-frequency loop antennas "by Andrew Alford and Arming G. Kandoian, published in AIEE Trans., 59, 1940, pp 843-848. In the first model of classical wire antennas, such as dipoles, simple and bent (folded dipols), as well as antenna systems that generate an omni-directional beam in a plane, with the electric field are described in detail polarized in that plane. The second is worth quoting the references to "Alford loops" or Alford circles as a first example of complex systems. A manual with more general descriptions and groupings wire antennas generally would book WL Stutzman and Thiele GA "Antenna Theory and Design" published by John Wiley & Sons, ISBN 0-471-0448-X, 1981.

In the design of these elements or devices, parameter to consider is the radiation pattern, that is, a graphical representation, depending on the direction, intensity of the EM field. Other parameters to be considered are: the bandwidth, which is the frequency range in which certain characteristics of directivity or gain are met. Similarly, they are to consider the width of the radiation beam and the polarization of the emitted or sensed signal (PH Smith, "cloverleaf Antenna for FM broadcasting", IRE Proc. 35, December 1947, 1556-1563, although the latter is illustrated and explained in the book Schelkunoff on page 504 et seq). In this reference, a planar antenna formed by four coils that generate an omnidirectional beam with linearly polarized electric field in the plane of the antenna, specifically designed for a specific application that was novel advantages offered by the later presented the 40 the article mentioned that "Cloverleaf Antenna" (Antena Clover) can be solved quickly and naturally perverse influence of environmental, especially snow and frost.

In the book of FH. Jasik, "Antenna Engineering Handbook", Me Graw HUI, I edition of 1961 (rather than later), speaks of "tripole radiator" consists of a flat array of three dipoles which also has an omni-directional beam similar to of "Cloverleaf Antenna". In communication Vassal'lo J., "low profile radiator with horizontal polarization on the horizon", presented at the National Symposium X URSI 95, Valladolid 1995, pp 743-746, the same radiator 3 dipoles occurs in a circular I made by photoetching techniques. In these references they are mentioned therefore different technologies on circular groupings of three electric dipoles, as well as 4 turns to achieve the same objective: an omni-directional pattern with the electric field linearly polarized in the plane of the antenna. In none of those references cited anything about another plane current distribution could generate other types of diagrams, in the case of the dipoles as in the turns.

Applications increasingly demand exclusive technical markets have passed the simplest antenna, such as dipole or the coil, to more complex. In "Satellite Communication with vehicles moving on Herat: a circular array antennas two prototype", published in the journal Micro waves and Optical Technology Letters, vol 39, no, ppl4 - 16, 5 October 2003, the authors F. Ares, G . Franceschetti, J. Mosig, S.Vaccaro, J. Vassal'lo and E. Moreno, grouping and have a plane circular microstrip radiators 8 that generates a cone-beam circular polarization for use in mobile communications satellite. This grouping provides the possibility of pointing to elevations between 35 ° and 55 ° on the plane of the antenna.

In this case, besides the polarization must be circular diagram required radiation needs its omni-directional character is defined along the line defined by the generatrix of a cone, so that for a mobile, located in a position given latitude on the earth's surface, can secure the connection to a geostationary satellite regardless of orientation having mobile. For those 35 ° and 55 ° elevation mentioned, it would ensure that forms the connection for a mobile that moves in the southern and central part of Europe.

The circularly polarized diagram is obtained as a result of the sum of the diagrams in circular polarization of each of the microstrip radiators 8. That is, microstrip radiators themselves, individually, working in a circular polarization. Extensive information on microstrip radiators and groupings of such radiators can be found in books: "Microstrip Antennas" I Bhal and Bhartia P., published by Artech House in 1980 and "Microstrip Antenna Design Handbook" by R. Garg , P. Bhartia, I. Bahl and A. Ittipiboon, published by Artech House in 2001, ISBN 0-89006-513- 6. The circular polarization can be obtained from radiating elements that work in linear polarization, whereby calls "sequential rotation". This is to distribute elements sequentially (3607n for each n elements), on a circumference, and offset rotated that amount, as can be seen in "3. Improvement of the co-cross polarization ratio" Barbero J. and J. Vassal'lo, in the chapter on "Contribution from Spain" the "Final Report of the COST 223 - Antennas in the 1990s, Active Array Antennas Satellite and Terrestrial Communications Future", published by the European Comission, Directorate General XIII : Telecommunications, Information Market and Exploitation of Research, Brussels, 1995. This technique for generating circular polarization is sufficiently known and valid, but is only applicable when the pointing direction coincides with the height of the antenna, that is, which is perpendicular to plane defined by circular grouping. In any case the possibility of obtaining a tapered beam circularly polarized mentioned, from a sequential rotation of radiating elements in linear polarization.

Diagrams not omnidirectional in a plane but with a maximum of radiation in a direction you determine, can also be obtained with antennas of threads, such as the antenna defined by Podger in his patent US 6,255,998 Bl. In this patent a radiating element referred to as "Lemniscate Antenna Element" (antenna element Lemniscata) providing maximum radiation with linear polarization, according to the direction perpendicular to the plane containing the antenna is defined.

This lemniscate antenna Podger comes to have a configuration similar to the "cloverleaf Antenna" of Smith, but with only two windings (the Smith has 4 coils), and with the essential difference that the current in the windings of the lemniscate circulates to the contrary, while the four turns of the antenna Smith, have the same rotational direction of the current. Moreover, in Patent Podger nor in other later the same inventor (US 6,469,674), is not mentioned in any case the possibility of circularly group several lemniscates antennas, all with the same center or feed point, to improve some of the characteristics of the assembly.

As is apparent from the description of lemniscate antenna by Podger in US 6,255,998 and US 6,469,674 patents, it may be seen as the particular case of one of the antennas daisies object of the invention herein. In particular is the case of only two daisy petals as in the invention daisy antenna herein, the number of petals presents only restriction being torque (can be 2, 4, 6 ...), and petals may have different flat geometries (not just referred to as "lemniscate curve") and thus could not be coils but may be used as petals other radiating element, such as dipole classic, microstrip radiators, or even guides open or finished to increase its directivity horn wave. Again, neither patent Podger mentioned, it is said that obtainable circular two lemniscates antenna polarization, placed one at 90 ° to each other in the same plane, and remote loops λ / 4 from the center of the pair of antennas, a lemniscata respect to the turns of the other lemniscata antenna.

BRIEF DESCRIPTION OF THE INVENTION.

The present invention is an antenna constituted by the grouping coplanar heating cables which assembly adopts a shape resembling the distribution of petals in a daisy (see Figure 1).

The heating cables or daisy petals antenna working in resonance, have planar geometry, all have the same structure and are contained in a same plane, called plane of the antenna. The only difference between the petals is in the relative distribution of the directions of current flow, which determines the shape of the radiation pattern and is essential in characterizing the operating behavior of the antenna.

DETAILED DESCRIPTION OF THE INVENTION

The reason for this patent antenna and we call "daisy" for simplicity, is constituted by coplanar grouping heating cables working in resonance, adopting a shape resembling a flower (see Figures 1 and 2), and with a special distribution current by the heating cables and determines fully characterizes the behavior of the antenna.

The heating cables or petals of the antenna, which in its general configuration take the contour shape of flower petals as well as working in resonance, have planar geometry are contained in the same plane, called plane of the antenna, and placed equidistant from the center of the antenna, where the antenna feed and the feeding circuit signal is petals.

The operating frequency band daisy antenna is in the range of microwave and millimeter wave.

The heating cables may consist of wires or conductive tubes, or also be made by photoetching techniques, being constituted by photoetched on dielectric substrate tapes.

Layered configuration Daisy antenna

Besides the supply circuit of the antenna (1), the elements of the antenna and can be seen in Figures 1 to 6 are: the petals or heating cables (2), and the distribution circuit (3) formed by adaptation or balun, the divisor, and if necessary the transmission lines to carry the signal from the splitter to the petals when they are located far from the center of the antenna. These elements, together with the petals of the antenna, over 3 parallel flat layers each, as shown in Figure 3.

This layering facilitates antenna design and optimize the symmetry of the antenna, to obtain emission characteristics sought. 3 shows the layering, a cross section view along the plane of the antenna. Petals (2) are located in the intermediate layer, while the circuit metallizations own signal distribution are at the top and bottom layers. Feeding the antenna (1) connected to the center of the antenna is perpendicular to the plane defined by the antenna, and is realized by coaxial line, similar to as if the stem that supports a daisy. Own coaxial power cable metallizations, are electrically connected to metallizations distribution circuit (top and bottom layers of the antenna).

Distribution circuit

It is one of the essential elements of the transmitter or receiver device, as will be seen as the description of operation of the antenna, set the directions of current flow in the petals. In the central area of ​​the antenna distribution circuit signal it is located, (3) in Figures 1 and 2, which is composed of:

• adaptation circuit,

• a splitter that distributes the signal to each of the petals,

· And bi-thread-lines (see (4) in Figure 4), which are used to carry the signal splitter to each of the petals. These lines are needed when the number of petals of the antenna is high, or the geometry of the petals so requires by its size or configuration. Figure 4 shows a daisy antenna with the same number of petals that the antenna shown in Figure 1, but located further away from the center. This implies the existence of bi-thread-transmission lines to carry the signal splitter to each petal (3). In the case of Figure 4, there are therefore many transmission lines as petals, and all these lines are exactly the same cross section and length so as not to introduce differences in response radiated by each petal, derived to provide different amplitude or phase.

The bi-thread-lines are part of the distribution circuit, along with the divisor and the matching circuit or balun.

The matching circuit design can be adjusted by varying the capacitance between the metallizations of the upper and lower layers, ie varying its area and / or separation between layers as well as separators using different dielectric constant therebetween.

petals

The petals are individual radiating elements, working in resonance and are characterized in that their structure is based on conductive wires or ribbons to produce a certain distribution of currents which depends the radiation produced.

The simplest structure is the electric dipole, but may also take other forms, such as: • coils with circular geometry, elliptical or polygonal, both regular and irregular document, and also any shape that was the result of a mixture of those mentioned above, provided that the total length of the loop is a multiple of the wavelength to fulfill the condition of working in resonance.

• any geometric shape given by a mathematical function defined in a plane, and whose length is a multiple of the wavelength to fulfill the condition of working in resonance. The petals may take different forms of geometric curves, into yarns or conductive strips to channel electric current. They must also work in resonance, so that its length should be a multiple of the wavelength.

It is therefore valid also used as daisy petals antenna double electric dipoles (also called dipoles folded), or even the classical electric dipole, since they are also antennas wires in their radiation pattern is characterized by the current distribution in the radiating element, thus presenting the particularity that reversing the direction of the current flowing through them, a phase difference of 180 ° is achieved in the phase of the radiated signal.

5 shows, for comparison, three antennas two daisy petals with different geometric shape each: similar to those of the antenna of Figure 2, folded dipoles petals, and classic electric dipoles. 6 shows a daisy antenna 6 petals, petal using electric dipoles.

The heating cables shaping the daisy petals antenna may be constituted by wires or conductive tubes, or also be made by photoetching techniques, being constituted by photoetched tapes on dielectric substrate.

Cassinian

The petals are radiating elements characterized by current distribution. As described lines above, a petal may be, for example, a wire-shaped loop and a loop in its broadest sense is what is called mathematically curve Jordan, ie any closed curve in the plane not cut itself. Examples of curves arise from Jordan called Cassinian. These are defined as the locus of the plane that meets the product of the distances from two fixed points (foci of the curve), is a constant. These curves are defined by the expression in Cartesian coordinates: Í ...,,, 2, 2 ..2, - ... 2 .. 2 - XJ _ ..4 Let's

[: + Y) - a \ x - y.! + = Or where, a = bk

Figure 7 shows the Cassinian for most representative values ​​of k: k = 1, k> 1. The Cassini oval generated with k = 1 is the best known and called lemniscate curve.

Ovals of Cassini are actually pairs of curves (when k> l), symmetrical about the center of coordinates, so are valid for antennas daisies even number of petals, but obviously can also be used as isolated elements for the case of daisies antennas odd number of petals.

Figure 8 shows a 6-petal daisy Cassinian generated using k = 1.1.

The ovals can be connected directly to the splitter, or through supply lines for electrically joining them to the divider, and thus remove them from the geometric center daisy antenna, similar to the case shown in Figure 4. Configurable analytical expressions petals

In order to automate the design process daisy antenna, it is useful to have analytic expressions that explicitly determining the geometry of the petals, from design parameters themselves. Besides the antenna design, there is also provided the use of computerized systems for other and different purposes, such as analysis of the electromagnetic antenna, making manufacturing plans, or use in manufacturing processes and assembly.

Mathematically it is known that few geometries that can be expressed analytically explicitly on the following design parameters:

• the curve length (L)

• the central opening angle petal (2a)

Cassini ovals do not support analytical expression about them, but nonetheless, you can define a family of curves parameterized overlooking analytically process automation. One of these families is given by the following expressions:

Figure imgf000012_0001

being :: Maii (¾)

sienuo) and where t is a number in the interval (-1, 1)

Expressions [1] explicitly give the coordinates of the petals, depending on the basic design parameters mentioned above:

· Petal length (L) which, when the resonant petals, must be a multiple of the wavelength at the central frequency of the operating band of the antenna

• the half-angle (a) opening petal, seen from its apex The advantage of the expressions [1], is that they are compatible with any computer system of numerical calculation, and therefore are integrable in the analysis process, design drawing or manufacturing antennas. Moreover, this same geometry supports a more simple expression for α = π case / 6

1

x (t, L, e): = ^ L (t 2 - l) - cos (0) Lt (t 2 - l) without (e)

[2]

Y (t, L, 9): = ^ L (t 2 - l) without (0) + Γ- to lt (t 2 - l) cos (Θ) where Θ is the angle between the symmetry axis of each petal with the abscissa.

Figure 9 shows the typical form of petal for α = π / 6 and θ = 0 o.

Being this geometry particularized for the case α = π / 6, supports the classic representation of the 6-petal daisy shown in Figure 10.

Since in the central area of ​​the antenna distribution circuit is placed, it is necessary to move radially petals and outwardly a distance D from the center of the antenna, so that the geometry of the petals is given by the expressions: x (t, L, 0, D)

Y (t, L, e, D)

Figure imgf000013_0001

Figure 11 shows the definition of the parameters used in this new geometry petal which displaced from the center of the daisy is a distance D.

It may even be obtained a simpler curve based on two straight and a section of circumference, which is an approximation to that given by the expressions [3]. This new geometry petal is based on the use of the circumference to three points: the outer end and the points of maximum and minimum of the curve given by the expressions [3] and trace then tangents to said circumference from petal vertex located in the center of coordinates. Figure 12 shows the geometry of this new curve to approximate petal expressions [3] and whose axis of symmetry is the abscissa.

13-L

The circle has a radius value: V 15552

center is located at the point of abscissa:

Figure imgf000014_0001

The tangents pass through the center of coordinates, and have a slope of:

Figure imgf000014_0002

Obviously, the slope of the tangents, is independent of the length of the petal (related to its operating frequency value), and only depends on the angle of central opening petal (2a), which in this case is fixed at π / 3.

Connections between layers and current direction on the petals

The connections between the metallizations of the upper and lower layers and the petals are made by way of a short circuit between layers. Thus the ends of the petals with the distribution circuit of the signal, one end of the petal is connected to the top layer and the other to the bottom are contacted. Depending on which end is connected to a layer or another, so will the direction of the current flowing through the petal.

As stated in the definition daisy antenna, the relative sense of the currents flowing through the petals, characterized the antenna performance and to obtain a maximum of the radiation pattern in linear polarization in the direction perpendicular to the plane antenna, just that:

• the antenna is formed by an even number of petals

• is defined in the plane of the antenna, a line of symmetry for the flow of petals, which should be parallel to the direction of the electric field of the desired linear polarization

• the distribution of currents in the petals of the antenna is made so that all the petals are positioned on the same side of the line of symmetry, have the same direction of current flow, and logically, that effect is counter-current which are located on the other side of the line of symmetry.

Figure 13 shows the top view of the metallization of the upper and lower layers of the antenna of 6 petals of figure 1. These metallizations form the distribution circuit (adaptation and divisor). Figure 14 shows the current distribution in the petals of said antenna.

Figure 15 shows the top view of the metallization of the upper and lower layers of the antenna of 6 petals of figure 4. These metallizations form the distribution circuit (adaptation divisor and bi-thread-transmission lines). Figure 16 shows the current distribution in the petals of said antenna, current distribution is identical to that shown in Figure 14. Figure 17 shows the top view of the metallization of the upper and lower layers of the antenna 6 petals, whose petals are simple electric dipoles. Comparing this Figure with Figure 15, it can be of different length feed lines derived from different sizes of petals. Obviously, the line width depends on the value of the impedance of the petal.

Figure 18 shows the current distribution in the dipole antenna or petals, and as such can be observed current distribution is identical to that shown in Figures 14 and 16 for the other antennas of 6 petals. Figure 19 shows the top view of the metallizations of the upper and lower layers of the antenna 2 petals, whose petals are electric dipoles. 20 shows the current distribution in the petals of said antenna. Comparing Figures 18 and 20, it can be seen that this antenna 2 coincides with the central petals daisy petals 6 petals.

Daisy antenna for maximum radiation circularly polarized in the direction perpendicular to the plane of the antenna

The circular polarization is obtained by interleaving two antennas equal daisies, rotated each 90 °, to generate the orthogonal linear polarizations, and adding one antenna length of a quarter of the wavelength guided in the line bi-thread-supply to introduce the required 90 ° phase shift between polarizations.

Thus, for maximum radiation pattern in circular polarization in the direction perpendicular to the plane of the antenna, it is sufficient that the antenna is formed by two antennas equal daisies, coplanar and with the same feed point, overlapping in the same flat, with the following features:

• the lines of symmetry that determine the distribution of each antenna currents must be orthogonal to the polarization of the field radiated by each antenna also is.

• feeding the antenna is only for the two antennas margarita and adaptation and divisor. If the antennas have two daisy petals each splitter must be 1: 4; if they have 6 petals, the divisor should be 1: 12.

• bi-thread-circuit signal distribution lines petals must differ by a quarter wavelength, to provide 90 ° phase shift required to generate circular polarization. That means the petals of daisies are distributed within the distribution of the other daisy petals. Since each of the daisy antennas generating the linear polarizations should have a pair of petals number (2, 4, 6 ... N petals), daisies antennas generating circular polarization must be 4, 8, 12 .. . 4N petals.

The simplest case is the antenna of four petals, which would grouping 2 2 margaritas petals each). Figure 21 shows the distribution circuit, separate the layers 2 and 3 as shown in the exploded figure 3. It can be seen in this figure, the different length of the lines feeding bi-bristles each daisies 2 petals that make this antenna. Figure 22 shows the distribution in layer 2 petals daisy with 4 petals (electric dipoles), which generates circularly polarized. In this figure, along with the current distribution, they can also be straight symmetry corresponding to each pair of petals, or what is the same, each polarization 5A 2A petals, and 5B for 2B petals. Figure 23 shows the view set of 3 superimposed layers shape antenna daisy 4 petals, whose petals are electric dipoles. 24 shows the distribution circuit in the layers 2 and 3 of a daisy petals 12 that generates circularly polarized. It would therefore be an antenna that is the sum of two antennas 6 petals daisies with petals of both intertwined. In this figure it can be seen that half (6) of the supply lines differ in length from those of the other half, a quarter wavelength guided wave, and that the lines of one of the daisy antennas 6 petals are interleaved between each other. This makes one stay contained within the other, with the same point or cord, or even using the same divisor, and thus both antennas have the same phase center of the radiated field. Figure 25 shows the distribution of petals in the intermediate layer, also showing the current distribution. This figure puts in evidence which is the set of six petals generating each of the two orthogonal linear polarizations needed for circularly polarized. Figure 26 the view of the three layers together antenna daisy petals 12 that generates circularly polarized.

As has been said, to have circular polarization in the direction perpendicular to the plane of the antenna, the antenna is daisy turn the sum of two sub-antennas daisies, so must have 4n petals. Seeing cases 4 and 12 petals, one might think that is adding the same antenna (2 or 6 petals) but rotated 90 °. This applies in cases where the antenna has no petal to 90 °, although more correctly would say that is one possibility, as in the case of 12 petals (2antenas 6), circular polarization may be obtained by turning 30 ° , 90 ° or 150 °, and 30 ° offsetting, 90 ° or 150 ° respectively, obtaining obviously cross in other directions with different polarization signal level.

For that reason, it is possible to obtain circular antenna 8 petals (adding two antennas 4 petals) polarization, but can not result from a rotation of 90 °, but 45 ° or 135 °, so that the distribution circuit You should introduce a phase shift in this case 45 ° or 135 ° respectively.

Daisy advantages antenna

The advantage of this new antenna concept lies in its ability to adapt to different types of application, being particularly useful:

• systems receive signals in broadband and average profit, such as signals of terrestrial television broadcasting, analog or digital, in urban areas, where the issuer's position is known but not visually located. Its simplicity of design and configuration provides a low manufacturing cost and low visual impact and ease of prompting the sender,

• passive observation systems in which to maintain the characteristics of the radiation in the operating band, as the shape of the diagram, the coverage area and signal polarization, are the most important and limiting system requirements.

• communications systems between mobile satellite, where the signal is circularly polarized, thus avoiding ignorance of the position or attitude of the satellite relative to the mobile, and having to turn the mobile antenna to match the satellite, as in the case that communication is carried off using a linearly polarized signal.

Increased directivity incorporating a ground plane

Directivity daisy antenna generates a radiation maximum in the direction perpendicular to the plane of the antenna, both linear polarization and circular may be increased by up to 3 dB by placing a flat mass parallel to the plane of the antenna, at a distance equal to one quarter of the wavelength of the operating frequency of the antenna, thus adding in phase in the desired direction, the signal reflected on the ground plane. Application of this concept to other different radiating elements of threads

Since the essential characteristic of Daisy antenna is in the distribution of the direction of flow of current through the petals, and this one has only two choices: to go or come, which means that the petals occurs, and a change position petal respect to all daisy antenna, a binary phase shift radiated by each petal signal, ie 0 or or 180 °, depending on how the direction of the current flowing through it.

This allows the concept defined for heating cables, also may apply to other types of radiating elements that support by building a binary phase shift of 0 or radiated at 180 °. It would for example the case of microstrip radiators or guides open or terminated speakers wave, in which only changing the position of the power that change of 0 or 180 ° is obtained in the phase of the signal radiated by each element, and maintaining the direction of linear polarization generated.

The antenna would have a configuration increases in complexity depending on the volume of the radiating element concerned, but would essentially similar to an electromagnetic operation daisy antenna previously defined and based on the use of threads. Figure 27 shows a sketch of a daisy antenna 6 petals with a maximum radiation in the direction perpendicular to the plane of the antenna (similar to those described benefits in Example 1), wherein the petals are small speakers in rectangular waveguide.

EXAMPLES OF APPLICATION OF THE INVENTION.

EXAMPLE 1 - daisy antenna for maximum radiation linearly polarized in the direction perpendicular to the plane of the antenna

Figure 28 shows the geometry of the upper and lower layers that form the distribution circuit and indicates the current distribution of an antenna daisy petals 4 generates a maximum in linear polarization in the direction perpendicular to the antenna plane. The base of the distribution circuit is a metal square of 30 mm side. The interlayer distance is 5 mm, so that separation between the upper and lower layers is 10 mm.

Figure 29 shows the geometry of the core layer containing the 4 petals are generated by gravure methods onto a dielectric substrate low effective permittivity. The width of the metal strip is 10 mm, and the length of the petal is 432 mm. Figures 30 and 31 show the two linear electric field components ΕΘ and ΕΦ and the gain value in the E and H respectively, planes of the radiation pattern of the antenna of four petals of figures 28 and 29, to 800 MHz frequency.

EXAMPLE 2 - daisy antenna for maximum radiation circularly polarized in the direction perpendicular to the plane of the antenna

Figure 21 shows the geometry of the upper and lower layers that form the distribution circuit and indicates the current distribution of an antenna daisy 4 petals, which generates a maximum circular polarization in the direction perpendicular to the plane of the antenna. The base of the distribution circuit is a metallic square with 40 mm sides, and the supply lines have a width of 20 mm. The difference in length between lines feeding the dipoles is 50 mm. The interlayer distance is 5 mm, so that separation between the upper and lower layers is 10 mm.

Figure 22 shows the geometry of the core layer containing the 4 petals, which in this case are electric dipoles 220 mm long. The width of the metal strip is 10 mm, and the length of the petal is 432 mm. All layers are generated by photoetching methods dielectric substrate low effective permittivity. Figure 23 shows the three superimposed layers to give an idea of ​​the whole.

Figures 32, 33, 34 and 35 show the two orthogonal components circularly polarized rightward and leftward electric field RHCP and LHCP and the gain value in the meridian cuts for Φ = 0 or, 30 °, 60 ° and 90 ° respectively, the radiation pattern of the antenna of four petals of figure 23 to the frequency of 730 MHz. figure 36 shows the axial ratio in dB versus the frequency in GHz. DESCRIPTION oF INDICATORS iN FIGURES

(1) - antenna feed

(2) - petals antenna

(2A) - petals generating horizontal linear polarization

(2 B) - petals generating the vertical linear polarization (3) - distribution circuit

(4) - supply lines divisor petals

(5) - short paths between layers

(6) - line of symmetry of the current distribution in the petals

(6 A) - line of symmetry of the petals generating horizontal linear polarization (6 B) - line of symmetry of the petals generating the vertical linear polarization

(7) - springs streamlines

(8) - sinks current lines DESCRIPTION OF THE FIGURES

Figure 1 shows an antenna 6-petal daisy.

Figure 2 shows daisy antennas 4 and 2 petals

Figure 3 shows a cross section of a daisy antenna

Figure 4 shows an antenna 6-petal daisy with power lines in distribution circuit

Figure 5 shows two antennas daisy petals with petal different geometry: polygonal petals, dipoles and electric dipoles folded

6 shows a daisy electric dipoles antenna 6

7 shows Cassinian for k = 1, 1.1 and 1.4

Figure 8 shows a group of six petals originated with three pairs of Cassinian with k = 1.1, in Φ = 0 or 60 ° and 120 °

Figure 9 shows a geometric curve derived from the expressions [2]

Figure 10 shows a geometric composition of a 6-petal daisy from expressions [2]

Figure 11 shows a geometric curve derived from the expressions [3]

Figure 12 shows a geometric approach to the curve Ngura 7 by a circle and two straight defined in [4]

13 shows metallization of the upper and lower layers of the antenna 6-petal daisy Figure 1.

Figure 14 metallization of the core layer of petals, indicating the distribution of current lines, daisy antenna shown in Figure 1

15 shows metallization of the upper and lower layers of the antenna 6-petal daisy Figure 4.

Figure 16 shows the metallization of the core layer of petals, indicating the distribution of current lines, daisy antenna shown in Figure 4. Figure 17 shows metallizations of the upper and lower layers antenna 6-petal daisy Figure 6.

Figure 18 shows the metallization of the core layer of petals, indicating the distribution of current lines, daisy antenna shown in Figure 6.

19 shows metallization of the upper and lower layers of the antenna 2 daisy petals of Figure 5 (electric dipoles).

Figure 20 shows the metallization of the core layer of petals, indicating the distribution of current lines, daisy antenna shown in Figure 5 (electric dipoles).

21 shows metallization of the upper and lower layers of the antenna daisy petals 4 that generates circularly polarized.

Figure 22 shows the metallization of the core layer of petals, indicating the distribution of power lines, antenna daisy petals 4 that generates circularly polarized.

23 shows an antenna daisy petals 4 that generates circularly polarized.

24 shows metallization of the upper and lower layers of the antenna daisy petals 12 that generates circularly polarized.

25 shows a metallization layer main petals, indicating the distribution of power lines, antenna daisy petals 12 that generates circularly polarized.

26 shows an antenna daisy petals 12 that generates circularly polarized.

27 shows an antenna 6-petal daisy with a maximum radiation in the direction perpendicular to the antenna plane, and where the petals are in rectangular guide horns.

28 shows metallization of the upper and lower layers of the antenna 4 daisy petals of Example 1, for linear polarization in the direction perpendicular to the antenna plane.

Figure 29 Metallization of the core layer of petals, indicating the distribution of power lines, antenna 4 daisy petals of Example 1, for linear polarization in the direction perpendicular to the antenna plane.

30 shows a plane E of the radiation at frequency 800 MHz, the antenna 4 petals of figures 28 and 29. The gain values ​​are expressed in dBi (curve diamonds) cut, and the dB of the two components of the radiated electric field: ΕΘ (curve triangles) and ΕΦ (square curve).

31 shows a plane cut radiation pattern H, the frequency of 800 MHz, the antenna 4 petals of figures 28 and 29. The gain values ​​are expressed in dBi (curve diamonds), and the dB of the two components of the radiated electric field: ΕΘ (curve triangles) and ΕΦ (square curve).

Figure 32 shows a meridian section of the radiation on Φ = 0 or antenna 4 daisy petals of figures 21, 22 and 23. The gain values are expressed in dBi (curve diamonds), and the dB of the two orthogonal circular polarization components in rightward and leftward electric field RHCP (square curve) and LHCP (curve triangles). Figure 33 shows a meridian section of the radiation on Φ = 30 °, antenna 4 daisy petals of figures 21, 22 and 23. The gain values ​​are expressed in dBi (curve diamonds), and the dB of the two orthogonal circular polarization components in rightward and leftward electric field RHCP (square curve) and LHCP (curve triangles).

Figure 34 a meridian section of the radiation on Φ = 60 °, antenna 4 daisy petals of figures 21, 22 and 23. The gain values ​​are expressed in dBi (curve diamonds), and the dB of the two orthogonal circular polarization components in rightward and leftward electric field RHCP (square curve) and LHCP (curve triangles).

Figure 35 a meridian section of the radiation on Φ = 90 °, the antenna daisy 4 petals of figures 21, 22 and 23. The gain values ​​are expressed in dBi (curve diamonds), and dB those of the two orthogonal circular polarization components in rightward and leftward electric field RHCP (square curve) and LHCP (curve triangles).

Figure 36 shows a graphical representation of the axial ratio in dB against frequency expressed in GHz, the antenna 4 daisy petals of figures 21, 22 and 23.

Claims

What is claimed
1. Antenna daisy transmission and / or reception of electromagnetic waves polarized linearly, characterized in that the circular grouping of a pair number of heating cables, the assembly adopts a shape resembling the distribution of petals in a daisy, and wherein the heating cables or petals working in resonance, have the same structure, are contained in the same plane called plane of the antenna, and the current flowing through the petals is arranged symmetrically with respect to a circular predefined diameter of clustering, which matches the linear polarization direction of the radiated electric field. This determines current distribution and operation characterized daisy antenna.
Antenna daisy for sending and / or receiving linearly polarized electromagnetic waves, according to claim 1, characterized in that it comprises the following elements, distributed in three layers (see Figure 3): a feeding line (1) at the center and connected to the radiating top and bottom layers of the antenna, the wires or elements also called petals (2) on the core layer of the antenna, and the distribution circuit (3) in the upper and lower layers, and which in time consists of the antenna matching or balun, the splitter to distribute the signal between the petals.
Antenna daisy for sending and / or receiving linearly polarized electromagnetic waves according to claims 1 and 2, characterized by the presence of bi-thread-lines to carry the signal from the splitter to the petals, or vice versa for reception presence which it is necessary when reason the size of the petals or design requirements, the petals are placed away from the divisor. These bi-thread-lines are equal in number to the petals, and must all be exactly the same from putting a difference in amplitude or phase in the transmitted signals.
Daisy antenna transmission and / or reception of linearly polarized electromagnetic waves according to claims 1, 2 and 3, characterized emit or receive signals in the direction perpendicular to the plane of the antenna.
5. Antenna daisy transmitting and / or receiving linearly polarized electromagnetic waves according to claims 1, 2, 3 and 4, characterized by having in the radiation maximum power in the direction perpendicular to the plane of the antenna. Antenna daisy for sending and / or receiving linearly polarized electromagnetic waves according to claims 1, 2, 3, 4, and 5, characterized in that can be used to generate circular polarization by interleaving two daisy antennas in the same plane, whose petals coincide as and number, rotated each with the same center, and sharing the same distribution circuit, and the only difference between the two daisy antennas that bi-ñlares recited in claim 3, lines have different lengths in each antenna with order to provide the phase difference needed to compensate for rotation between antennas and thereby generate a circular polarization sought.
Antenna daisy for emission and / or reception of linear or electromagnetic waves circularly polarized according to claims 1, 2, 3, 4, 5 and 6, characterized emit or capture electromagnetic radiation in the microwave range and the millimeter band of the electromagnetic spectrum . Antenna daisy for emission and / or reception of linear or electromagnetic waves circularly polarized according to claims 1, 2, 3, 4, 5, 6 and 7, characterized in that the Nn to pattern petals available analytical mathematical expressions its geometry, allowing explicitly determine them from the design parameters: its perimeter length and opening angle having as vertex the center of the antenna. This facilitates the use of computerized systems for other and different purposes, such as analysis of the electromagnetic behavior of the antenna, the development of manufacturing plans, or use in manufacturing processes and assembly.
Antenna daisy transmission and / or reception of electromagnetic waves linear or circularly polarized according to claims 1, 2, 3, 4, 5, 6, 7 and 8, wherein the petals are designed using the expressions:
X (t, m, L) = - - (t 2 - l) - t 2 (l Om - 5-Jm 2 + l) + 2-m - 3 · + 1
16
Y (t, m, L) =
Figure imgf000025_0001
where: L is the length of the perimeter of the petal
α twice the opening angle of the petal
m the tangent of α
t number in the interval (-1, 1)
10. Antenna daisy for sending and / or receiving electromagnetic waves linear or circularly polarized according to claims 1, 2, 3, 4, 5, 6, 7, 8 and 9, characterized in that the petals are designed using the expressions for the case in that the opening angle of the petal is π / 3:
x (t, L, 0, D): t = L (t 2 - l) sin (e) and (t, L, 9 D) to lt = (t 2 - l) -cos (e)
Figure imgf000026_0001
being:
L perimeter length petal
D vertex distance petal axis coordinate number t in the interval (-1, 1)
Θ the angle between the symmetry axis of each petal with the abscissa.
11. Antenna daisy for sending and / or receiving electromagnetic waves linear or circularly polarized according to claims 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10, wherein the petals are designed using a circumference and the two tangents drawn from the apex of the petal, being:
13- L
the circle radius value: 15552 V center is located at the point of
Figure imgf000026_0002
and tangents have a slope of
Figure imgf000026_0003
12. Antenna daisy for sending and / or receiving electromagnetic waves linear or circularly polarized according to claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11, wherein the petals are made by methods gravure, I serigrañado or electrochemical processes on the dielectric substrate, or by any other method that may arise in the markets for normal development or progress of technology.
13. Antenna daisy for sending and / or receiving electromagnetic waves linear or circularly polarized according to claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12, characterized in that the directivity of the antenna daisy designed for maximum radiation in the direction perpendicular to the plane of the antenna, both linear polarization and circular may be increased by a maximum of 3 dB, placing a ground plane parallel to the plane of the antenna, to a distance equal to a quarter of the wavelength of the operating frequency of the antenna, thus adding in phase in the desired direction, the antenna signal with reflected by the ground plane.
14. Antenna daisy for sending and / or receiving electromagnetic waves linear or circularly polarized according to claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 and 13, characterized by its use systems receiving terrestrial television, communication systems between fixed and mobile systems, linked through ground stations or satellite observation systems and security, as well as engaged in scientific and technical research systems.
PCT/ES2012/070123 2011-03-29 2012-02-28 Daisy antenna for the emission and reception of linearly and circularly polarized electromagnetic waves WO2012131126A1 (en)

Priority Applications (2)

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ES201130473A ES2395429B1 (en) 2011-03-29 2011-03-29 Daisy antenna for transmitting and receiving electromagnetic waves circularly polarized linear.

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005072716A (en) * 2003-08-20 2005-03-17 Furukawa Electric Co Ltd:The Circularly polarized wave antenna
EP2009735A1 (en) * 2007-06-22 2008-12-31 Philippe Herman Antenna with diversity of polarisation for transmitting and/or receiving audio and/or video signals

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005072716A (en) * 2003-08-20 2005-03-17 Furukawa Electric Co Ltd:The Circularly polarized wave antenna
EP2009735A1 (en) * 2007-06-22 2008-12-31 Philippe Herman Antenna with diversity of polarisation for transmitting and/or receiving audio and/or video signals

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ES2395429B1 (en) 2014-01-07 grant

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