Loaded antenna

OBJECT OF THE INVENTION

The This invention relates to a novel loaded antenna, on multiple bandwidth is simultaneously effective and a smaller Size as antennas provides according to the prior art.

Of the Radiators of the novel loaded antenna consists of two different Parts: a conductive surface with a polygonal, space-filling or multilevel shape; and a burdensome structure consisting of a set of strips connected to said first conductive surface.

The Invention relates to a new type of loaded antennas, mainly for mobile Communications or generally for all other applications is suitable, where the integration of telecom systems or applications in a single small antenna of importance are.

BACKGROUND OF THE INVENTION

the Growth of the telecommunications sector and in particular the expansion private mobile communication systems drive the engineering services the development of multi-service (multi-frequency) systems and compact Requiring systems multifrequency and small antennas above. For this reason, nowadays the use of a small multi-system antenna with a multi-band and / or broadband functionality, the coverage of the greatest number provides services of great Interest, as it will allow telecommunications providers, reduce costs and minimize environmental impact.

The Most of the proposed multi-band antenna solutions use one or several radiators or feeders for each band or each service. An example is in the<patcit><text>US Pat. No. 09/129176</text></patcit> entitled "Multiple ribbon, multiple branch antenna for mobile phone "[" multiband, multi-branch antenna find mobile phone "].

A the alternatives which may be of particular interest when Searched for antennas with a multi-band operability and / or smaller size is, consists in multilevel antennas, Patent Publication <patcit><text>WO01 / 22528</text></patcit> entitled "Multilevel Antennas "[" multilevel antennas "], and in room-filling Miniature antennas, Patent Publication <patcit><text>WO01 / 54225</text></patcit> entitled "Space-filling miniature antennas "[" Space-filling miniature antennas "]. In particular in the publication <patcit><text>WO01 / 22528</text></patcit> is a multilevel antenna characterized by a geometry which polygons or polyhedron same class includes (same number of sides or faces) which are electromagnetically coupled and grouped to form a larger structure. In a multi-level geometry, most of these elements clearly visible since their contact area, intersection or link (if these exist) with other elements is always less than 50% which Scope or their surface is at least 75% of the polygons or polyhedron.

In Posted <patcit><text>WO 01/54225</text></patcit> was a space-filling miniature antenna defined as an antenna, of which at least one part as a space-filling Curve (RFK) is formed, said RFK defined as a curve is that formed by at least ten connected straight segments is, said segments smaller than a tenth of the operational Free space wavelength are and spatially are arranged in such a way that none of said adjacent and connected segments to another longer straight Segment defined.

The international publication <patcit><text>WO 97/06578</text></patcit> with the title Fractal antennas, resonators and onerous elements describes Elements in the form of a fractal that can be used to provide a form antenna.

A Variety of techniques that are used to determine the size of the antennas to reduce, can be found in the prior art. 1886 was carried out the first example of a loaded antenna; while it was loaded to the built of Hertz to validate the Maxwell equations Dipole.

AG Kandoian (AG Kandoian, "Three new antenna types and their applications "[" Three new antenna types and their applications "], Proc. IRE, Volume 34, pages 70W-75W February 1946) led the concept of loaded antennas and demonstrated a, such as the length of Monopole antenna can be reduced by one-quarter wavelength, by a conductive disk is added to the top of the radiator. subsequently presented Goubau an antenna structure with several capacitive disks was great burden, which were coupled with inductive elements, and a smaller size with a larger bandwidth available set, as in the <patcit><text>US Pat. No. 3,967,276</text></patcit> With entitled "Antenna structures having reactance at free end "is displayed.

recently sets the <patcit><text>US Pat. No. 5,847,682</text></patcit> With entitled "Top loaded triangular printed antenna "[" top-loaded, triangular, printed antenna "] a triangular shaped open printed antenna whose tip with a verbun rectangular stripsthe is. The antenna has a low Profile and broadband operability on. None of these antenna configurations but provide a multiband behavior available. In the patent application No. <patcit><text>WO0122528</text></patcit> with the Entitled "Multilevel Antennas "[" Multilevel Antennas "], another patent application the present inventors, there is a particular case of a top-loaded Antenna with an inductive loop, which was used an antenna for to miniaturize a dual frequency operation. Also W.Dou and WYMChia (W.Dou and WYMChia, "Small broadband stacked planar monopole "[" Small broadband, stacked, planar monopole antennas "], Microwave and Optical Technology Letters, Volume 27, pages 288-289, November 2000) presented another special precursor a top loaded antenna with a broadband behavior. In the Antenna there was a rectangular monopole antenna was top loaded with a rectangular arm of each of Tips of the rectangular shape was connected. The width of each of the rectangular arms is in the range of the width of bespeisten Element, which in the case of the present invention is not the case is.

SUMMARY OF THE INVENTION

at of the invention is a loaded antenna according to claim 1. Some embodiments are in the dependent Claims defined. The key point the present invention is in the form of the radiator of the Antenna, which consists of two main parts: a conducting surface and a burdensome structure. has the said conducting surface a polygonal, space-filling or multilevel shape and the loading structure consists of a conductive strip or a set of stripes, said the conductive surface are connected. According to the present invention must be at least a burdensome strip with at least one point on the circumference the said conducting surface be directly connected. Furthermore, circular or elliptic shapes in the set of possible geometric shapes of said conductive surfaces included, since these considered polygonal structures with a large number of pages can be. The features of the structure are defined in claim stressful first

by virtue of adding the burdensome structure, the antenna is a small version and Multiband operability and sometimes a multiband and Broadband operability offer. About that addition, the multiband properties of the loaded antenna (number of bands, spacing between the bands, appropriate levels, etc. are adjusted) by the geometry of the Load and / or the conductive surface changed is.

The novel loaded antenna allows a multi-frequency functionality to acquire, with similar radioelectric parameters are achieved in different bands.

The loading structure may for example be made of a single conductive Strips are made. In this particular case, one of the two Ends of said strip with a stressful point on the Scope of the conductive surface be connected (ie the corners or edges). The other tip of said strip is left free in some embodiments, while in other embodiments also with a point on the perimeter of said conducting area connected is.

The loading structure can not only a single strip, but also include a variety of stressful strips at different Positions of its periphery arranged along.

The Geometry of the load with the present invention, the conductive surface can be connected, is: A space-filling curve, Pat. <patcit><text>PCT / ES00 / 00411</text></patcit> entitled "Space-filling miniature antennas "[" Space-filling miniature antennas "].

The The form of at least one stressful stripes is a space-filling curve, wherein said curve is a curve of at least ten is formed segments that are connected such that each segment an angle with its adjacent segments forms, that is, no pair of adjacent segments longer, straight segment defined, and wherein, when the curve along a fixed straight direction periodically runs in the space, the period is defined by a non-periodic curve, the is formed from at least ten connected segments, with no Pair of said adjacent and connected segments, straight, longer Segment, and wherein said curve does not even overlap or yourself overlaps only at its beginning and end points. In the said segments may be acting straight segments.

In some versions is the above-described loading structure with the conductive area , whereas in other embodiments, Tips a variety of stressful strip with another strip are connected. In those embodiments where a new burdensome strip is added to the previous one, said added load can either a tip without connection, or said tip connected connected to the previous stressful stripes, or both tips with the previous strip, or a Tip connected to the previous strip and the other tip connected to the conductive exhibit space.

It are three types of geometries that present according to the invention for the used conductive surface can be: <ul><li>a) A polygon (i.e., a triangle, square, trapezoid, Pentagon, hexagon, etc. or even a circle or an ellipse as a special case of a polygon with a very large number of edges).</li><li>b) A multilevel structure, Pat. <patcit><text>WO0122528</text></patcit> entitled "Multilevel Antennas "[" Multilevel Antennas "].</li><li>c) A solid surface with a space-filling Extent.</li></ul>

In some versions even a central part of said conducting surface removed, to the size of the antenna further reduce. Skilled persons will also be clear that the multi-level or space-filling versions in the configurations b) and c) can be used to For example, to approximate ideal fractal shapes.

Of the The main advantage of this novel loaded antenna is two-fold: <ul><li>• The Antenna has a multiband or broadband operability or a combination of both.</li><li>• Given the physical size of the radiator can the said antenna at a lower frequency than most Antennas are operated according to the prior art.</li></ul>

<figref idrefs="S26">1</figref> and <figref idrefs="S27">2</figref> show some unclaimed examples of the spotlight for a loaded antenna. In the drawings <figref>1</figref> to <figref>3</figref> is it with you the conductive surface a trapezoid, while the said face in the drawings <figref>4</figref> to <figref>7</figref> a triangle. It can be found that the conductive surface charged in these cases is by using different strips with different lengths, orientations, and positions are used around the periphery of the trapezoid around, <figref idrefs="S26">1</figref>, also , the load in these examples, either one or both of their Ends connected to the conductive surface have, <figref idrefs="S27">2</figref>,

BRIEF DESCRIPTION OF THE DRAWINGS

parts describe and illustrate the description and drawings Antennas, which do not coincide with the invention as claimed, the however, were shown for the purpose and described, the public more information available deliver.

<figref idrefs="S26">1</figref> shows a trapezoidal unclaimed antenna under three different ways Using the same structure is loaded; in particular a straight strip. In the event of<figref>1</figref> a straight strip the loading structure (<figref>1a</figref>) And (<figref>1b</figref>) at every of the tips of the trapezoid of the conductive surface (<figref>1c</figref>) Added. case<figref>2</figref> is same as case <figref>1</figref>But strips are used, a smaller length have and at a different position on the periphery of the conductive area are arranged. case<figref>3</figref> is a more general case, wherein a plurality of strips at two different positions on the conductive surface added are. drawing<figref>4</figref> shows an example of a non-symmetrical, loaded structure, and drawing <figref>5</figref> shows an element, in which only a chamfered Strip was added to the upper end of the conductive surface. After all make cases <figref>6</figref> and <figref>7</figref> Examples of Geometries, and which with a strip with a triangular loaded rectangular shape and with different orientations are. In these cases is only one of the ends of the loads connected to the conductive surface.

<figref idrefs="S27">2</figref> shows a different, unclaimed particular configuration, when it is at the expense of curves that such a maximum nine segments are formed that each segment forms an angle forms with its adjacent segments has already been mentioned above. Furthermore in the drawings <figref>8th</figref> to <figref>12</figref> both the ends of the loads connected to the conductive surface. drawings <figref>8th</figref> and <figref>9</figref> are two examples, in which the conductive surface page loaded is. cases<figref>13</figref> and <figref>14</figref> put two cases represents in which a rectangle having a molded as described above open curve is top loaded, wherein the compound by a is carried out of the tips of the rectangle. The maximum width of incriminating Strips is smaller than a quarter of the longest edge of the conductive Area.

<figref idrefs="S28">3</figref> shows a square structure as claimed three different space-filling Curves is peak load. When the load on the square Curve case used geometry <figref>16</figref>, it is about the well-known Hilbert curve.

<figref idrefs="S29">4</figref> shows three examples of unclaimed top loaded antenna, wherein said load consists of two different loads that to the conductive surface added are. In drawing<figref>19</figref> is a first, with three segments formed load to the trapezoid added, and then a second Last added to the first.

<figref idrefs="S30">5</figref> includes some examples of a loaded antenna, in which only the copy <figref>23</figref> as is claimed in even a central part of leiborder area is removed to the size of the antenna still further reduce.

<figref idrefs="S31">6</figref> shows the same in <figref idrefs="S26">1</figref> described unclaimed loaded antenna; in this case, however, a conductive surface as Multilevel structure used.

<figref idrefs="S32">7</figref> shows another example of the non-claimed loaded antenna, similar to the in <figref idrefs="S27">2</figref> described. In this case, the conductive area from a multi-level structure. drawings<figref>31</figref>. <figref>32</figref>. <figref>34</figref> and <figref>35</figref> use different shapes for the load in all cases however, both ends of the load connected to the conductive surface. case <figref>33</figref> is an example of an open load, a conducting multilevel surface was added.

<figref idrefs="S33">8th</figref> provides some examples of the loaded antenna is very similar to those in <figref idrefs="S28">3</figref> and <figref idrefs="S29">4</figref> shown, but a multi-level structure used as a conductive surface. The representations <figref>36</figref>. <figref>37</figref> and <figref>38</figref> contain a space-filling lace onerous curve as claimed, while the remaining drawings Three examples of unclaimed top loaded antenna with multiple levels of load show. drawing<figref>40</figref> provides represents an example where three loads to the multilevel structure added were. More specifically, the conductive surface is first treated with the curve (<figref>40a</figref>) loaded, then the curves (<figref>40b</figref>) And (<figref>40c</figref>). In the case of the curve (<figref>40a</figref>) Are both ends of the conductive area connected, wherein the curve (<figref>40b</figref>) Are both ends to the previous load (<figref>40a</figref>), And wherein the two segments formed load (<figref>40c</figref>) Is one end connected to the load (<figref>40a</figref>) and the other to the load (<figref>40b</figref>) connected.

<figref idrefs="S34">9</figref> shows three cases where the same multilevel structure, in which the central Parts of the conductive surface have been removed, loaded with three different types of loads is; It is a space-filling curve, a curve with at least two and a maximum of nine segments on the above-mentioned type are connected, and ultimately to a load with two similar Levels. Only the copy<figref>42</figref> as claimed an antenna.

<figref idrefs="S35">10</figref> shows two configurations of unclaimed loaded antenna, the three conductive surfaces include, where one of them is larger than the other. The drawing <figref>45</figref> shows a triangular conducting surface (<figref>45a</figref>) the above a conductive strip (<figref>45d</figref>) And (<figref>45e</figref>) with two smaller round conductive surfaces (<figref>45b</figref>) And (<figref>45c</figref>) connected is. The drawing<figref>46</figref> is a similar Configuration as drawing <figref>45</figref>, Wherein, however, the larger conductive area is a multilevel structure.

<figref idrefs="S36">11</figref> shows other special cases unclaimed loaded antenna. These consist of a Monopole antenna a conducting or superconducting ground plane (<figref>48</figref>) With an opening for receiving a coaxial cable (<figref>47</figref>) Whose outer conductor with said ground plane and the inner conductor with the loaded antenna connected is. The loaded radiator can optionally via a supporting Insulators (<figref>49</figref>) to be placed.

<figref idrefs="S37">12</figref> shows an unclaimed top loaded polygonal spotlight (<figref>50</figref>) Provided with the same configuration as the antenna in <figref idrefs="S36">11</figref> is mounted. The radiating radiator can either via a supporting insulator (<figref>49</figref>be placed). The lower Drawing shows a configuration in which the radiator on a the sides of a dielectric substrate (<figref>49</figref>printed) and wherein the load also has a conducting surface on the other side of the substrate (<figref>51</figref>) Has.

<figref idrefs="S38">13</figref> shows a special unclaimed configuration of the loaded antenna. It consists of a dipole wherein each of the two arms and two having just strip loads. The lines at the node of the small Triangles (<figref>50</figref>) Show the input terminals. The two drawings provide different configurations of the same Grunddipols represents; in the lower drawing is the radiator of a dielectric substrate (<figref>49</figref>) carried.

<figref idrefs="S39">14</figref> shows in the upper drawing, an example of the same unclaimed, with two stripes page loaded dipole antenna, however, as one opening having antenna is fed. refers The lower drawing to the same loaded structure wherein the conductor is the Scope of the loaded geometry defined.

<figref idrefs="S40">15</figref> shows a non-claimed patch antenna, which is in the spotlight a top-loaded with two strips arms multilevel structure These upper drawing. The figure also shows an antenna with openings in which the opening (<figref>59</figref>) On a conducting or superconducting structure (<figref>63</figref>) accomplished is, said opening is shaped as a loaded multilevel structure.

<figref idrefs="S41">16</figref> shows a non-claimed frequency selective surface wherein the elements, the area the form, as a loaded multilevel structure are formed.

DETAILED DESCRIPTION OF SOME EXAMPLES NOT CONSUMED

at an unclaimed example of the loaded antenna is it is a monopoly configuration as in <figref idrefs="S36">11</figref> shown. The antenna includes a conducting or superconducting counterforce or ground plane (<figref>48</figref>). A portable telephone housing or even a part of the metallic structure of a car or train can be used as such a mass drag act. The mass and the Monopolarm (in this case, the arm with the loaded structure (<figref>26</figref>) illustrated, each of the aforementioned loaded antenna structures could however used instead) are, as with monopole antennas common in the prior art, means, for example, a transmission line (<figref>47</figref>) Excited. Said transmission line is made two conductors, said one of the conductors to the ground reaction force connected while the other loaded with a point of conducting or superconducting Structure is connected. In<figref idrefs="S36">11</figref> has been a coaxial cable (<figref>47</figref>) As a special case of a transmission line used, but it is professionals understood that other transmission lines (Such as a Mikrostreifenarm) could be used, the Monopole antenna to excite. Optional and according to the scheme just described may the loaded monopole antenna on a dielectric substrate (<figref>49</figref>) to be printed.

On another unclaimed example of the loaded antenna is a monopole configuration as in <figref idrefs="S37">12</figref> shown. The arrangement of the antenna (Einspeiseschema, ground plane, etc.) the same as that of the execution, in the <figref idrefs="S36">11</figref> will be described. In the this figure is another example of a loaded Antenna before. More specifically, this consists of a trapezoidal member connected to a the mentioned Curves is peak load. In this case, one of the main differences is that, since the antenna on edge on a dielectric substrate is, this is also a conductive surface on the other side of the Nonconductor (<figref>51</figref>) Encloses with the shape of the load. These Configuration allows to miniaturize the antenna and also adjust the multiband parameters of the antenna, such as the distance between the bands.

The <figref idrefs="S38">13</figref> describes a non-claimed example. A two-arm antenna dipole is formed, comprising two conducting or superconducting parts, wherein each part to a page loaded multilevel structure concerns. Because of Clarity but without loss of generality, here was a special Case, the loaded antenna (<figref>26</figref>) Selected; it is obvious, that other structures, such as in the <figref idrefs="S27">2</figref>. <figref idrefs="S28">3</figref>. <figref idrefs="S29">4</figref>. <figref idrefs="S32">7</figref> and <figref idrefs="S33">8th</figref> described, could be used instead. Both the conductive surfaces and the onerous structures are on the same surface. The next two tips the two arms form the input terminals (<figref>50</figref>) Of the dipole. The connections (<figref>50</figref>) Were drawn as conducting or superconducting wires; like but it will be professionals realize could such connections by any other pattern can be formed, as long as they respect the Operating wavelength be kept small. Professionals will notice that the arms the dipoles can be rotated and folded in different ways to the input impedance or the radiation properties of the antenna, such as the polarization to change exactly.

On is another unclaimed example of a loaded dipole also in <figref idrefs="S38">13</figref> illustrated in which the conducting or superconducting loaded arms on a dielectric substrate (<figref>49</figref>) Are printed; this method is particularly useful in terms the cost and mechanical robustness when the shape of the applied Last a long length packed into a small area and when the conductive surface a contains high number of polygons, as it happens with multilevel structures. Each of the well-known Techniques for the production of printed circuits can be used are to the loaded structure on the dielectric substrate replicate. In said dielectric substrate may be for example, a glass fiber board, a teflon based Substrate (such as Cuclad^®) or other standard radio frequency and microwave substrates (as for instance Rogers 4003^® or Kapton^®) Act. The dielectric substrate may be a part of a window glass, if the antenna in a motorized vehicle such as a car, a Train or an airplane is to be installed to radio, TV, mobile phone (GSM900, GSM1800, UMTS) or other electromagnetic waves of to transfer communication services or to receive. A balun network can of course at the input terminals of the be connected or integrated dipole to the current distribution balance between the two dipole arms.

the unclaimed example (<figref>26</figref>) in <figref idrefs="S39">14</figref> consists from an opening configuration a loaded antenna, a multi-level geometry as a senior Surface used. The Einspeisetechniken it may be one of the techniques which normally in conventional Antennas with apertures be used. In the described figure is the inner conductor of the coaxial cable (<figref>53</figref>) Directly to the lower triangular Element and the outer conductor with the remaining conductive surface connected. Other feeding configurations are possible, such as for example capacitive coupling.

at another non-claimed example of the loaded antenna If it is a slot loaded monopole antenna as shown in the lower drawing in <figref idrefs="S39">14</figref> illustrated is. In this figure the loaded structure forms a slot or a gap (<figref>54</figref>), Of a conducting or superconducting film (<figref>52</figref>) embossed is. Such a film can, for example, a sheet over a its dielectric substrate in a board configuration, a transparent conductive film such as those glass windows on a will be launched to the inside of a car in front of the infrared rays aufheizenden to protect, or it may even be part of the metallic structure of a portable Phone, be a CARS, train, boat or aircraft. In the Einspeiseschema may it be conventional to any of the well known schemes Slot antennas act, and this is no essential Part of the present invention. In both of said two representations in <figref idrefs="S39">14</figref> , a coaxial cable for feeding the antenna used, one of the conductors connected to one side of the conductive Film and the other to the other side of the film over the slot connected is. A microstrip transmission line could for Example be used instead of a coaxial cable.

On another unclaimed example is in <figref idrefs="S40">15</figref> described. It consists of a patch antenna, wherein the conducting or superconducting patch (<figref>58</figref>) The loaded structure (the special Case, the loaded structure (<figref>59</figref>) Was used here, However, it is clear that instead, any other of the mentioned structures could be used). The patch antenna includes a conducting or superconducting ground plane (<figref>61</figref>) Or ground reaction force and the conducting or superconducting patch, of having mentioned Ground plane or ground reaction force is parallel. The distance between the patch and the ground is typically below (limited but not on) a quarter wavelength. Optionally, a low-loss dielectric substrate (<figref>60</figref>) (Such as glass fiber, a Teflon substrate as Cuclad^® or other commercial materials such as Rogers 4003^®) in between said patch and ground reaction force be placed. The antenna feeding scheme can be understood as any of the well known schemes, the for patch antennas be used according to the prior art, for instance: a coaxial cable, whose outer conductor to the ground plane and the inner conductor with the patch on the desired input resistance point connected (of course, the typical modifications may also be used, the a capacitive gap on the patch around the coaxial connection point around or capacitive plate, with the inner conductor of the coaxial cable is connected with a parallel distance to the patch, and so further include); a microstrip transmission line which the same ground plane as the antenna used, the strip capacitively coupled to the patch and with a distance below arranged patch, or in another embodiment with the strip under placed the ground plane and a slot coupled to the patch, and even a microstrip line with the strip plane parallel to the patch. All these mechanisms are of the prior art well known and do not substantially Part represents the invention.

the same <figref idrefs="S40">15</figref> describes another unclaimed example of the loaded antenna. It consists of an antenna with openings, said Antenna is characterized in that the loading structure is added to a multilevel structure, said aperture to a conductive ground plane or ground reaction force is printed, wherein said ground plane, for example, from a wall of a waveguide or cavity resonator or a part of the structure of a motorized Vehicle (such as a car, a truck, an airplane or a tank) consists. The opening can work with any of the conventional Techniques are fed, such as a coaxial cable (<figref>61</figref>) or a planar microstrip or interconnect transmission line, to name just a few.

On another unclaimed example is in <figref idrefs="S41">16</figref> described. It consists of a frequency selective surface (<figref>63</figref>). is In frequency selective surfaces there are essentially electromagnetic filters that in some Frequencies completely energy reflect while they are completely transparent at other frequencies. In this preferred embodiments use the selective elements (<figref>64</figref>), The surface (<figref>63</figref>) form, the loaded structure (<figref>26</figref>), But may also any other of the mentioned loaded antenna structures can be used instead. At least one of the selective elements (<figref>64</figref>) Has the same Form of the aforementioned loaded radiator. Besides this example, another example a loaded antenna where the conducting surface or the loading structure or both by one or a combination of the following mathematical Algorithms are formed: iterative function systems, multiple decimation copier, networked multi Reduction copier.