Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
  • H01Q1/364—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith using a particular conducting material, e.g. superconductor
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
  • H01Q15/02—Refracting or diffracting devices, e.g. lens, prism
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
  • H01Q19/06—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using refracting or diffracting devices, e.g. lens
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
  • H01Q19/06—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using refracting or diffracting devices, e.g. lens
  • H01Q19/09—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using refracting or diffracting devices, e.g. lens wherein the primary active element is coated with or embedded in a dielectric or magnetic material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
  • H01Q9/04—Resonant antennas
  • H01Q9/0485—Dielectric resonator antennas
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
  • H01Q9/04—Resonant antennas
  • H01Q9/30—Resonant antennas with feed to end of elongated active element, e.g. unipole
  • H01Q9/40—Element having extended radiating surface

Definitions

• the present invention is in the field of electromagnetic antennas. More specifically, the invention relates to a reconfigurable antenna by electrowetting.
• an electromagnetic antenna is composed of a radiating element, a dielectric and a ground plane.
• the radiating element and the ground plane are most often metallic. They have very different shapes and sizes.
• terminals and / or communicating objects are constrained in size, weight and have a low energy autonomy .
• These terminals and / or communicating objects require antennas which are miniaturized, on the one hand, and which can satisfy, on the other hand, a set of constraints related to the radio system. For example, these antennas must be able to simultaneously cover all the frequencies of a broad band of frequency or at least these antennas must have a great agility in frequency to be able to scan a broad spectrum of frequencies.
• the antenna is agile in frequency.
• the antenna can thus scan a broad spectrum of frequencies.
• Such antennas are used in mobile terminals that can be compatible with several communication standards such as the GSM standard (for Global System for Mobile Communications in English) which relates to a frequency band around 900 MHz and UMTS (Universal Mobile Telecommunications System in English) which concerns a frequency band around 1800 MHz.
• GSM Global System for Mobile Communications
• UMTS Universal Mobile Telecommunications System in English
• the antenna is agile in polarization.
• this polarization can be horizontal or vertical and for a circular polarization, it can be left or right.
• Such antennas make it possible to obtain a better signal-to-noise ratio and are of great interest in places where the propagation of electromagnetic waves encounters numerous obstacles, for example inside buildings.
• Antenna reconfigurable radiation pattern The antenna is then able to modify its radiation pattern to, for example, adapt to a change in the propagation environment.
• the reconfiguration of an antenna is obtained by switching certain elements, among the radiating element, the dielectric and the ground plane, which compose it, or by varying impedances connected at certain points of the antenna. .
• the elements switching and impedances for reconfiguration, have intrinsic losses that affect the efficiency of the antenna.
• the present invention relates to an electromagnetic antenna that is remarkable in that it comprises a radiating element composed of a first fluid substance, conducting electricity, resting on a first element and a second substance. fluid relying on a second element, the first fluid substance being in contact with the second fluid substance, which fluid substances being immiscible and which first and second elements being electrically conductive and electrically isolated from each other.
• the antenna according to the invention has the advantage of comprising a radiating element no longer metallic but composed of a fluid substance which is by nature deformable.
• the first fluid substance is a substance rendered electrically conductive by the introduction into this substance of particles or fragments of a conductive element or by the introduction into this substance of a conductive substance
• the radiating element (fluid substance and fragments) special electromagnetic properties.
• the resonant frequency is not necessarily fixed by the size and volume of the fluid substance but is also a function of possible refolding fragments that may have very large lengths deployed. This allows the antenna to operate in much lower frequency bands than in the case of a simple fluid substance.
• the second element is composed of a set of sub-elements electrically insulated from each other.
• the decomposition of the second element into sub-elements makes it possible to facilitate and better control the deformation of the assembly. It is possible to obtain asymmetrical deformation.
• the contact surfaces of the first and second elements with respectively the first and the second fluid substance are flat or concave or convex.
• the shape taken by the contact surface of the elements with the fluid substances makes it possible to compensate the effects due to the weight of the fluid substance (effects of gravity), to increase the size of the fluid. antenna and therefore to be able to use it in lower frequency bands.
• At least one of the contact surfaces of the first and second elements with respectively the first and the second fluid substance is covered with a layer of an insulating material.
• the introduction of a layer of an insulating material makes it possible to isolate the fluid substances and to avoid chemical reactions between the fluid substances and the contact surfaces of the elements with the fluid substances.
• the contours and the volume of the first fluid substance are reversibly deformed by applying a potential difference between the first and the second element.
• Deformation of the contours and volume of the first fluid substance can be slow and gradual. Given the flexibility of the constituent substances of the antenna, this deformation is reversible. The deformation being continuous, the reconfiguration of the antenna is also continuous, progressive and reversible. These features greatly enhance the adaptability of the antenna.
• the contours and the volume of the first fluid substance are deformed by applying a plurality of potential differences between the first element and each of the sub-elements of the second element.
• the second element can be decomposed into sub-elements, the deformation of the contours and the volume of the first fluid substance can be asymmetrical.
• the reconfiguration of the antenna, in particular in polarization and radiation pattern, is greatly improved.
• the antenna according to the invention comprises a protective cover enclosing the first element, the second element, the first fluid substance and the second fluid substance.
• the invention also relates to a method for reconfiguring an antenna as described above, said method comprising an operation of deforming the contours and the volume of the first fluid substance by applying at least one potential difference between the first and the second element.
• a method of reconfiguring an antenna according to the invention has the advantage of being continuous, progressive and reversible.
• the invention also relates to a radiocommunication terminal comprising an antenna as described above.
• FIG. 1 represents a view in longitudinal section of an antenna according to a first embodiment of the invention
• FIG. 2 represents an alternative embodiment of the antenna represented in FIG. 1;
• FIG. 3 represents a cross-sectional view along a plane P for a particular embodiment of the antenna represented in FIG. 1;
• FIG. 4 represents a view in longitudinal section of an antenna according to a second embodiment of the invention
• FIG. 5 is a cross-sectional view along the plane P of an alternative embodiment of an antenna such as that represented in FIG. 3;
• FIG. 6 illustrates the application of a reconfiguration method according to the invention to an antenna according to the invention
• FIGS. 7a and 7b illustrate other examples of application of the reconfiguration method according to the invention.
• FIG. 8a illustrates another example of application of the reconfiguration method according to the invention
• FIG. 8b illustrates, in a cross-sectional view along plane P, the example of application of the reconfiguration method according to the invention of FIG. 8a,
• FIGS. 9a and 9b illustrate other examples of application of the reconfiguration method according to the invention.
• FIG. 10 shows an antenna according to the invention provided with a protective cover.
• FIG. 1 represents a longitudinal sectional view of an antenna according to a first embodiment of the invention
• the antenna shown in FIG. 1 comprises an RF (radio frequency) port for transmitting and receiving signals.
• the RF port is connected to a first element Si which conducts electricity.
• the element Si is surrounded by an insulating element S 3 separating it from a second electrically conductive element S 2 , the element S 2 surrounding the element S 3 .
• first fluid substance F 1 highly electrically conductive. As shown in FIG. 1, the fluid substance F 1 is also in contact with a part of the element S 3 .
• the fluid substance F 1 has a surface tension comparable to that of the oil.
• the fluid substance F 1 can be a liquid, a body in a solid-liquid transition phase or a soft and flowing material, polymer type.
• the volume of the fluid substance F 1 is low and may, for example, be similar to that of a drop.
• the fluid substance F 2 is also in contact with a part of the element S 3 .
• the fluid substance F 2 has a surface tension comparable to that of water.
• the fluid substance F 2 may be water or a liquid having properties comparable to those of water.
• Fluid substances F 1 and F 2 are immiscible.
• Fluid substances F 1 and F 2 are in contact at a contact surface S c .
• the fluid substance F 2 covers the fluid substance F 1 .
• the fluid substance F 1 is made conductive electricity by the introduction into this substance of particles or fragments of a conductive element. These particles or fragments may be carbon nanotubes or other conductive filaments. These particles or fragments may be suspended in the fluid substance F 1 or adhere to the element S 1 through a flexible and conductive connection means. According to another variant embodiment not shown, the fluid substance F 1 is made conductive electricity by the introduction of a conductive fluid substance mixed with the fluid substance F 1 .
• FIG. 3 represents a cross-sectional view along the plane P for a particular embodiment of the antenna in which the element S 1 is a disc and the elements S 2 and S 3 are rings of the same center as that of the S 1 disk.
• FIG. 4 represents a view in longitudinal section of the antenna according to another embodiment of the invention in which the elements S 1 , S 2 and S 3 are concentric rings.
• the RF port is in direct contact with the fluid substance F 1 .
• FIG. 5 represents a cross-sectional view along the plane P of an alternative embodiment of the antenna for which the element S 2 is composed of a set of n sub-elements SE 1 with i varying from 1 to n .
• the sub-elements SE 1 are electrically isolated from each other.
• the surface formed by the surfaces of the elements S 1 , S 2 and S 3 in contact with the fluid substances F 1 and F 2 can be flat as shown in FIGS. 1, 2 and 4. It can also be concave (for example , to form a kind of bowl) or convex.
• the radius of curvature must be less than a certain threshold. If this threshold is exceeded, the effects of gravity acting on the fluids can cause a tear of the outer "envelope" of these fluids.
• the fluid substances are transformed into droplets at the contact with the convex surface formed by the surfaces of the elements S 1 , S 2 and S 3 .
• At least one of the surfaces of the elements S 1 , S 2 and S 3 in contact with the fluid substances F 1 and F 2 is covered with a thin layer of an insulating material .
• This thin layer makes it possible to isolate the fluid substances F 1 and F 2 and thus to avoid chemical reactions between the fluid substances F 1 and F 2 and the surfaces of the elements S 1 , S 2 and S 3 .
• the invention also relates to a method for reconfiguring an antenna according to the invention.
• FIG. 6 illustrates the application of a reconfiguration method according to the invention to an antenna according to the invention.
• a voltage source T is connected to the element S 2 of an antenna as described above.
• the arrows drawn in FIG. 6 represent the direction of displacement of the contours and the deformation of the fluid substances F 1 and F 2 .
• a reconfigurable antenna is thus obtained by deformation of the contours and a volume of a conductive fluid substance.
• FIG. 7a illustrates an example of application of the reconfiguration method according to the invention.
• Deformation represented by the arrows, of the contours and volumes of the two fluid substances F 1 and F 2 is obtained by applying a voltage T 1 .
• the deformation produced leads to obtaining a significant radiating length and therefore a relatively low operating frequency.
• FIG. 7b illustrates another example of application of the reconfiguration method according to the invention.
• a deformation, represented by the arrows, of the contours and volumes of the two fluid substances F 1 and F 2 is obtained by the application of a voltage T 2 different from T 1 .
• the deformation produced leads to obtaining a lower radiating length than in the previous example and therefore to a higher operating frequency.
• the element S 2 is composed of a set of n sub-elements SE 1 with i varying from 1 to n (embodiment shown in FIG. 5), it is then possible to apply different potential differences between the element Si and each of the sub-elements of the element S 2 . It is thus possible to obtain a non-uniform or asymmetrical deformation of the volume of the fluid substance F 1 . This type of deformation makes it possible to obtain a reconfiguration of the antenna in polarization, in addition to the reconfigurations always possible in frequency and in radiation pattern.
• FIG. 8a illustrates another example of application of the reconfiguration method according to the invention.
• asymmetric deformation of the contours and volumes of the two fluid substances F 1 and F 2 is obtained by applying different voltages T 1 and T j for respectively two sub-elements SE 1 and SE j of the element S 2 .
• FIG. 8b illustrates, according to a cross-sectional view along the plane P, the preceding example of application of the reconfiguration method according to the invention as illustrated in FIG. 8a.
• FIGS. 9a and 9b illustrate other examples of application of the reconfiguration method according to the invention.
• FIGS. 9a and 9b illustrate examples of application of the reconfiguration method according to the invention similar to those represented respectively in FIGS. 7a and 7b but for which the surface formed by the surfaces of the elements S 1 , S 2 and S 3 in contact with the fluid substances F 1 and F 2 is concave.
• FIG. 10 represents an antenna according to the invention provided with a protective cover.
• the protective cover makes it possible to enclose the various constituent elements of the antenna such as the elements Si, S 2 and S 3 and the fluid substances F 1 and F 2 .
• the protective cover consists of solid walls.
• the walls consist of the surfaces S 1 , S 2 and S 3 and of a closure surface S F of the entire device.
• the protective cover can also enclose a third fluid substance F 3 , immiscible with the fluid substances F 1 and F 2 .
• This third fluid substance F 3 makes it possible to fill the empty spaces between the walls of the protective cover and the elements that it contains.
• the invention also relates to a radiocommunication terminal or any communicating object adapted to receive an antenna according to the invention.

Landscapes

• Details Of Aerials (AREA)
• Variable-Direction Aerials And Aerial Arrays (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=39580301

Family Applications (1)

Country Status (4)

Families Citing this family (4)

Family Cites Families (13)

• 2008
  • 2008-11-04 CN CN2008801154654A patent/CN101855583B/zh active Active
  • 2008-11-04 EP EP08854738.5A patent/EP2229601B1/de active Active
  • 2008-11-04 US US12/741,391 patent/US8373605B2/en active Active
  • 2008-11-04 WO PCT/FR2008/051987 patent/WO2009068774A2/fr not_active Ceased

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events