Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/12—Supports; Mounting means
  • H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
  • H01Q1/24—Supports; Mounting means by structural association with other equipment or articles with receiving set
  • H01Q1/248—Supports; Mounting means by structural association with other equipment or articles with receiving set provided with an AC/DC converting device, e.g. rectennas
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
  • H02J50/20—Circuit arrangements or systems for wireless supply or distribution of electric power using microwaves or radio frequency waves
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
  • H02J50/20—Circuit arrangements or systems for wireless supply or distribution of electric power using microwaves or radio frequency waves
  • H02J50/27—Circuit arrangements or systems for wireless supply or distribution of electric power using microwaves or radio frequency waves characterised by the type of receiving antennas, e.g. rectennas
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
  • H02J50/40—Circuit arrangements or systems for wireless supply or distribution of electric power using two or more transmitting or receiving devices

Definitions

• the present invention relates to the field of devices for converting an electromagnetic wave, and in particular microwaves into a DC voltage.
• It relates more particularly to a device for converting an electromagnetic wave into a DC voltage comprising: at least one antenna capable of converting said electromagnetic wave into an electrical input signal; a first filter adapted to filter said input electrical signal and generate a filtered signal;
• a rectifier adapted to rectify said filtered signal and generate an output voltage
• a second filter capable of filtering said output voltage so as to generate said DC voltage.
• the rectifier consists of a single diode and constitutes a simple alternating rectifier.
• Such a device can be used to power remote devices.
• microwaves generated by a microwave source are received by the conversion device, which converts the received wave into a DC voltage.
• This DC voltage can be used to power a load, such as a rechargeable device.
• US-B-6,427,065 discloses a device for converting an electromagnetic wave into a DC voltage comprising: at least one antenna adapted to convert said electromagnetic wave into an input electrical signal; a first filter adapted to filter said input electrical signal and generate a filtered signal; a rectifier adapted to rectify said filtered signal and generate an output voltage; a second filter (6) adapted to filter said output voltage so as to generate said DC voltage, wherein the rectifier is a full-wave rectifier.
• a first object of the invention is therefore to improve the efficiency in a device for converting an electromagnetic wave into a DC voltage.
• Another object of the invention is to limit the energy level of the electromagnetic wave to be supplied to an electromagnetic wave converter in a DC voltage, while maintaining a satisfactory electrical energy.
• a device for converting an electromagnetic wave into a DC voltage comprising: at least one antenna capable of converting said electromagnetic wave into an electrical input signal ; a first filter capable of filtering said input electrical signal and generating a filtered signal; a full-wave rectifier adapted to rectify said filtered signal and generate an output voltage; a second filter capable of filtering said output voltage so as to generate said DC voltage,
• first filter and the second filter are arranged to respect a sequence of current and voltage sources through the rectifier.
• the efficiency of the converter is improved.
• the rectifier is a direct rectifier
• the first filter is a voltage generator as seen from the rectifier
• the second filter is a current generator as seen from the rectifier.
• the rectifier is a direct rectifier
• the first filter is a current generator as seen from the rectifier
• the second filter is a voltage generator as seen from the rectifier.
• the electromagnetic wave is a wave in the microwave field
• the antenna is arranged to convert the microwave wave.
• the full wave rectification is not used in the DC voltage conversion devices known from the state of the art.
• This full-wave rectifier is for example a bridge of Gra ⁇ tz only composed of diodes.
• a dual alternating rectifier such as a Graetz bridge as a rectifier in a device for converting an electromagnetic wave into a DC voltage, all the energy taken by the antenna is rectified and converted to continuous energy. This therefore improves the efficiency of the converter.
• a full-wave rectifier such as a Graetz bridge according to the invention makes it possible to maintain a good efficiency for the conversion device because the diodes within the Graetz bridge operate in commutation, that is to say in a part of their characteristic where losses are small.
• Such a Graetz bridge has never been used in microwave conversion devices, in a DC voltage in particular because the use of switching diodes is not widespread in the microwave community because the diodes are used for demodulation purposes which leads to use another part of their feature.
• Conversion structures such as Gra ⁇ tz bridges are commonly used in low frequency but without impedance matching, which amounts to rejecting harmonics on the power grid which is infinite power compared to the load.
• the invention relates to a device for converting microwaves into a DC voltage.
• a microwave conversion device is more particularly called rectenna, or "rectenna" in the English language.
• the application FR 2, 646, 739 mentioned above relates more particularly to this technical field of the rectennes.
• the invention relates to a device for converting microwaves into a DC voltage
• a device for converting microwaves into a DC voltage comprising: at least one antenna capable of converting microwaves into an input electrical signal; a first filter adapted to filter said input electrical signal and generate a filtered signal; a rectifier adapted to rectify said filtered signal and generate an output voltage; a second filter capable of filtering said output voltage so as to generate said DC voltage, in which the rectifier is a full-wave rectifier, in particular a bridge comprising only switching diodes, for example a Graetz bridge.
• the above device solves the problem of improving the efficiency of the microwave converter, regardless of the arrangement of filters described above respecting the sequence of sources in current and voltage across the rectifier.
• the fact of improving the efficiency is particularly important with regard to the standards preventing the emission of microwaves beyond a certain energy.
• the filtering according to the invention between the antenna and the rectifier by the first filter is not possible at low frequencies because of the size of the components in this frequency range.
• This first filter makes it possible in particular to perform an impedance matching which is a major concern in microwave frequencies in order to be able to capture a maximum energy m of the incident wave with the receiving antenna.
• said first filter comprises a first input electrical component arranged to receive said input signal, and wherein said first input electrical component is an inductance.
• the antenna is a voltage source
• the first component encountered by the output current of the antenna is a current generator type.
• voltage generator then current generator thus makes it possible to improve the power transfer.
• said rectifier is a direct rectifier and said first filter comprises an electrical output component, said electrical output component being a capacitor
• said second filter comprises a second input electrical component arranged to receive said output voltage, said second input electrical component being an inductor.
• said rectifier is a direct rectifier and said first filter comprises an electrical output component, said electrical output component being an inductance, and said second filter comprises a second input electrical component arranged to receive said voltage. output, said second input electrical component being a capacitance.
• the rectifier is a direct rectifier, there is no element of energy accumulation within the rectifier, and the sequence of sources, voltage generator and current generator therefore improves power transfer.
• the invention also relates to an electrical equipment comprising a device as previously described, and a load capable of being powered by said voltage.
• said first filter, said rectifier, said second filter and said load form a reduced set connected to said antenna, led it together brought back having a reduced impedance, said antenna having an antenna impedance, said set brought back di amension of so that said impedance brought back is equal to said antenna impedance.
• the filters, and in particular the impedances and capacitances of the filters are chosen so as to achieve impedance matching in the device. In a manner known per se, the equality of the impedance brought down and the impedance of the antenna makes it possible to maximize the energy transfer between the antenna and the load.
• F I G. 1 is a general diagram of a device for converting an electromagnetic wave into a DC voltage according to the invention associated with a microwave electromagnetic source;
• - F I G. 2 is an electrical diagram of an exemplary embodiment of a device for converting an electromagnetic wave into a DC voltage according to the invention;
• F I G. 3 is a circuit diagram of an electric circuit equivalent to the circuit of the F I G. 2 in terms of impedance;
• - F I G. 4 is a graph showing the power recovered across a load in a device as illustrated by FI G. 1 depending on the load resistance.
• a device 1 for converting an electromagnetic wave 11 into a DC voltage comprises an antenna 3.
• the antenna 3 is adapted to convert the electromagnetic wave 11 is an AC electrical signal.
• An association of several antennas 3 may possibly be used in order to increase the reception area.
• the alternating electric signal is then transmitted in the device 1 successively through a high frequency filter 4, a full-wave rectifier 5 adapted to transform a signal alternating to a rectified signal, and a continuous filter 6.
• a DC voltage is generated. This DC voltage can then be applied to a load 7.
• the electromagnetic wave 11 is, for example, a microwave signal 11 generated by a transmitter device 2.
• This transmitting device 2 comprises, for example, a DC voltage generator 9, a microwave source 8, and a transmitting antenna 10.
• the microwaves generated by the transmitter 2 have the advantage of being easily transmitted in an open environment in which the microwaves can propagate, which makes possible a remote transmission to the receiver device 1.
• the transmitter device is known to those skilled in the art and will not be discussed in more detail later.
• the high frequency filter 4 positioned between the antenna 3 and the rectifier 5 has the function of adapting the impedance seen by the antenna. This impedance matching will be discussed in more detail below.
• FIG. 2 Illustrated FIG. 2, we now describe a particular embodiment of the various electrical components of the receiver device 1 of the FI G. 1.
• the antenna 3 can be modeled by a voltage generator E1, and a resistive impedance R1.
• the impedance R1 is for example 50 Ohms.
• the high frequency filter 4 comprises an inductor L2 connected directly to the impedance R1 of the antenna 3, and a capacitor C2 positioned in parallel with the antenna 3.
• the high frequency filter 4 is a low pass filter.
• the output of the high frequency filter 4 is connected to a full-wave rectifier 5.
• This full-wave rectifier 5 is a Graetz bridge and comprises an assembly of four diodes distributed over two branches of two diodes. The inputs of the bridge are located at from each of the two branches. The diodes of this full-wave rectifier 5 operate in a manner known per se.
• the continuous filter 6 is positioned at the output of the rectifier 5 and comprises an inductor L1 in series with the rectifier 5, and a capacitor C1 in parallel with the rectifier 5.
• the filter 6 is a low-pass filter.
• the continuous filter 6 makes it possible to generate a DC voltage that can be supplied to the load 7 that can be modeled by a resistor R2.
• the value of the charge 7 is calculated according to the consumption of the components to be powered by the device 1. For example, for a component with a consumption of 10 mW at 5 volts, a resistance R2 of 2500 Ohms will be used.
• the capacitors C1 and C2, and the inductors L1 and L2 are positioned so as to respect the principle of the sequencing of the sources so as to obtain a maximum power transfer.
• the generator E1 and the resistor R1 modeling the antenna constitute a voltage generator.
• the inductor L2 being positioned at the top of the filter 4, the filter 4 is therefore seen as a current generator by the antenna 3.
• the inductor L1 is positioned at the top of the filter 6, which is therefore seen as a generator current through the filter 4, which is itself a voltage generator output on the C2 side. Since the rectifier 5 is a direct converter, the stringing condition of the sources is well respected according to the invention, which makes it possible to obtain good power transfer.
• the order of the filters 4 and 6 can be increased, by positioning other inductance and capacitance.
• these inductances and capacitors are also positioned so as to respect the sequence of voltage-current sources.
• the output component of the filter 4 is an inductor
• the input component of the filter 6 will be a capacity so as to respect this sequence of sources.
• an impedance adaptation of the device 1 is made when it is connected to a load 7.
• the capacitors C1 and C2 and the inductances L1 and L2 are therefore sized to achieve this impedance matching.
• the Applicant has determined values of the components L1, C1, L2, and C2 making it possible to achieve good impedance matching for a purely resistive internal impedance antenna of 50 Ohms.
• FIG. 4 is a graph showing the power recovered across the load 7 in the receiver device 1 as shown in FIG. 1 depending on the resistance R2 of the load 7.
• the curve 13 corresponds to an incident field 1 1 at the antenna 3 of 130 V / m.
• Curve 14 corresponds to an incident field 1 1 at antenna 3 of 100 V / m.
• Curve 15 corresponds to an incident field 1 1 at antenna 3 of 75 V / m.
• Curve 16 corresponds to an incident field 1 1 at antenna 3 of 50 V / m.
• the yields obtained by the device 1 of the present invention make it possible to provide a DC voltage generator, in particular from a microwave source, with good efficiency.
• the invention can in particular be applied to the remote power supply and be inserted into an energy terminal for nomadic devices or for remote charging. It can also be applied to the supply of micro-systems.

Landscapes

• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Power Engineering (AREA)
• Rectifiers (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=37695900

Family Applications (1)

Country Status (5)

Cited By (1)

Families Citing this family (11)

Citations (5)

Family Cites Families (51)

• 2006
  • 2006-05-12 FR FR0604264A patent/FR2901061B1/fr not_active Expired - Fee Related
• 2007
  • 2007-05-11 EP EP07766028A patent/EP2022161B1/fr not_active Not-in-force
  • 2007-05-11 JP JP2009508442A patent/JP5769371B2/ja not_active Expired - Fee Related
  • 2007-05-11 US US12/300,600 patent/US20100141051A1/en not_active Abandoned
  • 2007-05-11 WO PCT/FR2007/051250 patent/WO2007132113A1/fr not_active Ceased

Patent Citations (5)

Also Published As

Similar Documents

Legal Events