WO2007128857A1

WO2007128857A1 - Inductive telemetry device for powering and controlling systems remotely

Info

Publication number: WO2007128857A1
Application number: PCT/ES2007/070088
Authority: WO
Inventors: Jorge SACRISTÁN RIQUELME; Maria Teresa OSÉS OLLO
Original assignee: Consejo Superior De Investigaciones Científicas
Priority date: 2006-05-09
Filing date: 2007-05-08
Publication date: 2007-11-15

Abstract

The invention presented relates to a telemetric device capable, by means of a wireless connection, of transmitting electromagnetic energy in a controlled and optimized manner to a system located remotely. The device is also used to transmit information that makes it possible to program the system and to receive information from its location. This invention solves the problem of how to access a system in a hermetically closed place, such as a sensor placed inside living beings, a pressure sensor in a gas cylinder, in a packaged product, etc. This novel system requires less energy and allows more secure communication.

Description

TITLE

TELEMETRY INDUCTIVE DEVICE FOR FEEDING AND CONTROLLING DISTANCE SYSTEMS.

SECTOR OF THE TECHNIQUE.

The invention consists of a telemetry device designed and realized to transmit energy and information by inductive coupling. It belongs to the sector of technical applications in which it is necessary to use an electronic device that must be powered and controlled remotely. The device proposed in this patent can be applied in sectors such as, among others: biomedicine, for implants and feeding, in order to control the prepared products. It also has application in electronics, in robotics and in general in all the installation in which it is necessary to act in places of difficult or impossible access.

STATE OF THE TECHNIQUE.

Our society has a degree of development such that the most common and popular activity would be unthinkable if we were not able to send energy and information in the form of orders, to distant places. The technical discipline that brings together the knowledge to make this possible efficiently, is telemetry. Indeed, we are all well acquainted with any of the numerous applications of this discipline; The most popular is the remote control of the home TV. There are others that, although very technical and complicated, enjoy, without a doubt, the admiration of the people; we are referring to the interplanetary probes that we often contemplate in the media of visual and written press. The present invention describes an inductive telemetry system for the transmission of energy and information, by means of an electromagnetic field, designed with the primary purpose of feeding and / or controlling, at a distance, machines or installations. Telemetry systems, based on inductive coupling, have already been used in applications where the equipment to be fed or controlled, is in an isolated, distant place or may even be stored, either due to its danger, or by necessity, in a Enclosure closed. It is clear that in such cases, you never have direct access to the installation and, therefore, it is well worth using the possibilities that telemetry gives us. The fundamental objective of a telemetry system is undoubtedly to transmit energy efficiently, that is, that the energy consumed in the transmitter (PT) during the process is applied to the load of the receiver (PR) minimizing losses generated on the road and at the same time achieve high speeds of data transmission, in a sustained way and with the minimum reduction of energy. This parameter, efficiency, defined by identity,

ET = 100 * PR / PT

It is a necessary criterion when you want to emit and receive energy, with the consequent optimal consumption, without shortening the life of the power units in the emitter and receiver equipment. These units may have a short operating life, we are thinking, for example, in the trivial case of batteries that are discharged from use. In addition, having high speeds in the transmission of data allows us to better control the receiving or slave systems and that these have greater functionality.

Despite everything desired and sought by engineers and researchers to date, in the telemetry systems or procedures used to date, this transmission efficiency is very low, mainly because this parameter is related to several other factors. and each one of them is, in turn, in a different proportion. In fact, we know that efficiency is related to the load on the receiver, consumption and remote coupling. This makes it necessary, in most cases, to have to re-tune the first one frequently based on the slightest change of these parameters. But, it is also necessary to take into account that in most cases or practical situations, the user or the operator does not have access to the receiver for manual re-tuning, and this results in an inevitable reduction in efficiency or sometimes arrives until the abandonment of the equipment. Our patent presents an inductive telemetry system based on a new receiver that tries to mitigate or avoid these unwanted or negative effects. We propose an assembly that achieves, as a major innovation, that the receiver does not have to be re-tuned after a modification of the load or coupling, with which we achieve greater efficiency in the transmission-reception of energy.

In addition to everything described so far, we must also point out that the transmission of energy uses alternating carrier signals of a certain frequency, which must be rectified in the receiver to, in this way, obtain the energy in continuous electrical voltage necessary for the more diverse applications, for example, moving mechanical parts. Current technology still uses rectifiers that dissipate much of the energy received and this, of course, means a reduction in the efficiency in the transmission-reception of energy. In the case of the patent we present, the proposed rectifier has a 50% lower voltage drop than the rectifiers used so far, thus achieving an improvement and, what is the same, greater efficiency.

Regarding the transmission and reception of information, if the transmission is made by modifying the signal level to identify the logical 1 and 0 (OOK modulation), the modulation index (IM) is defined by the relationship between the signal level for logical 1 (Vl) and 0 (VO),

IM = (1 - Vl / V0) * 100

In all existing models in the current market of this type of components, the rectifier is connected in parallel to the resonant receiver, in order to obtain the continuous energy and thus feed a load [see references, 1- 5]. However, if it is considered that in this type of assembly, the signal in said load must be continuous, the modulation index must be null, which means that information cannot be transmitted. Therefore, in the end, a compromise between reception of energy and transmitted data must be established, which inevitably reduces efficiency and limits the speed of data transmission. On the contrary, the receiver and the rectifier presented in this patent mean that the load and the rectifier do not modify the modulation index received and therefore facilitating demodulation and allowing to obtain higher transmission speeds. In summary, we can affirm that the current inductive telemetry systems are far from providing good results of the parameters defined to characterize their performance: it has been said that they are, the energy transmission efficiency (described above) and the transmission speed of data. This observed lack is due to the fact that in the current devices, or assemblies, given the type of modulation used, the transmission and modulation functions dissipate a relatively high power, resulting in that the transmitters become inefficient for the remote sending of energy. To all this we must add that the modulation depends on the response of the transmitter and the intensity of the electromagnetic signal, which causes the transmission speed to be reduced; In addition, also, since the modulation is performed on the signal and this in turn depends on the electronic configuration of the transmitter, the intensity of the emitted signal is hardly modifiable. This means, finally, that it is impossible to exercise full control of the power in order to optimize the energy sent according to the needs. In the specific case of the receiving device, a configuration is used in which the load and the resonant receiver circuit are in parallel to be able to obtain the continuous energy and be able to be used by a device and / or application, the result of this configuration is that, the received signal is altered by the load and the rectifier filter, being a consequence of the fact that the circuit is in parallel with the receiver resonant circuit. Another inconvenience to be solved is that the energy is only applied to the load in a pulsating manner and with times less than the half cycle of the alternating reception signal, so that energy will only pass to the load in the proportion in which the signal is greater than Continuous load level, reducing rectification efficiency. Another effect that is obtained from the rectification with filter, is that this affects the level of the signal obtained and the modulation index decreases, thereby limiting the speed of information transfer and / or the implementation of the demodulator is difficult. It is also necessary that the systems currently on the market suffer from the tuning of the receiver, it is modified by the coupling since it depends on the distance and the load being more inefficient when the load is greater and therefore requiring an improvement in the transmitter to correct the need to send more energy and be less efficient at reception. In the case of the transmitter of a telemetric device, a modulation method is normally used in which a device modifies the amplifier's energy level. This has the added disadvantage that said modulating device dissipates power and therefore decreases the efficiency of energy transmission, also reduces the bandwidth of the amplifier which implies a limitation in the speed of data transmission. As in the case of the receiver, a compromise between the efficiency in the transmission of energy and the speed of data transmission must be established.

Another difficulty, present in current technology, is that the transmitter modifies the level of the signal to be transmitted, to perform the modulation in a similar way to how a change in the energy to be transmitted would be made. The result is that power and modulation are related and if one intends to modify one the other is altered, this leads to the situation that when there is a modification of the transmission power the modulation index is modified and the amount of information that can be send is altered.

The device object of the invention in this patent, aims to radically solve the problems associated with the transmission and reception of data and energy in telemetry. For this, a new transceiver system is proposed that allows the sending of information more efficiently, while allowing the user to control the energy sent to optimize the consumption in the transmitter. To this end, a new scheme is defined to perform the modulation that will allow users a greater speed in the transmission of information in addition to having a new assembly for the recovery of the energy that without modifying the modulation index achieves greater efficiency in the transmission of this. Thus the reception of the information is much simpler and higher transmission speeds are obtained with high performance in the reception of energy. A second advantage of our invention is that the response of this new system is independent of the possible variations in the distance or misalignment between the transmitter and receiver coils, making system re-tuning unnecessary. This results in a final system much more efficient than those currently available. The third advantage is that in the receiver proposed by us, contrary to the used in the state of the art, increases its efficiency by increasing the load, that is, the consumption, being optimal the higher the energy requirements.

Let us mention here a possible example of application of this invention at the request of specialists in health sciences. It is an electrical stimulator implanted under the skin of a living being. Its function is to inject a pulsed current that causes, in general, a certain motor or sensory action [1,2]. In this case, the implant is in the patient's body and is intended to work without the need for an external cable connection avoiding the problems derived in the systems connected through wires such as infections, or the need for a feeding by batteries that would limit the life of the implant. To this end, an inductive telemetry system is available that sends the energy through a magnetic field and at the same time this channel is used to send the information required for implant control.

Another possible application of these devices is the use of the telemetry system to feed the circuits associated with a sensor and its programming and to measure a certain experimental variable [3, 6]. A more concrete example would be that of a chemical sensor that is in a medium that is not accessible and with which it is intended to obtain certain information. This application, in particular, constitutes a breakthrough with broad industrial applications. With the intention of giving a general description, we also cite one more application. A waterproof system that has adapted an electronic device with batteries which must be recharged periodically. The present invention would allow efficient energy transmission by reducing the time required for charging.

[1] D. Marín, I. Martínez, E. Calderón, R.M. Villa, J. Aguilo "Sacral root stimulation system by radio frequency fed implant" ES 2 164 017 A2.

[2] Babak Ziaie, Mark D. Nardin, Anthony R. Coghlan, Khalil Najafi, "A Single-Channel Implantable Microstimulator for Functional Neuromuscular Stimulation" IEEE Trans Biomed Eng. Vol. 44, no. 10, 1997 [3] CC. Collins "Miniature Passive Pressure Transcensor for Implanting in the Eye" IEEE Trans Biomed. Eng. VoI. 14 pp. 74-83,1967

[4] M. Sawan, Y. Hu, J.Coulombe "Wrireless Smart implants Dedicated to Multichannel Monitoring and Microstimulation" IEEE Circuits and Systems Magazine, pp 21-39

[5] Clemens M. Zierhofer and Erwins S. Hochmair "High-Efficiency Coupling- Insensitive Transcutaneous Power and Data Transmission via an Inductive Link" IEEE Trans. Biomed Eng. VoI 37, no 7, July 1990.

[6] J.M. English and M. G. Alien, "Wireless Micromachined Ceramic Pressure Sensors" in Proc IEEE MEMS Conference, pp 511-516, 1999

[7] G. A. Kendir, W. Liu, G. Wang, M. Humayun, J. Weiland. "An Effϊcient Inductive Power Link Design for Retinal Prosthesis" IEEE ISCAS 2004 IV pp 41 -44

DESCRIPTION OF THE INVENTION

- Brief description of the invention. The present invention consists in the design and manufacture of a telemetric transceiver device, by means of an inductive coupling, with which to send energy and computer orders to remote installed systems. The applications of this invented device extend and improve those already taken into account by the systems currently in use.

- Detailed description of the invention.

As stated above, current inductive telemetry systems are far from providing good results of the parameters defined to characterize their performance. The proposed invention is a transceiver system that substantially improves the problems so far not resolved in current systems and methods, obtaining greater efficiency in the transmission of energy and / or data. The transmitter of the invention presented (Figure 1) is based on a system in which the data to be transmitted uses digital coding with an OOK (On-Off-Keying) modulation (two different levels for the T and ¹ O 'data) and the coding is carried out by means of a modulator, in which the signal to be transmitted is not modulated, as was the case until now, but is based on modifying the value of the capacity associated with the resonant transmitter system to transmit the energy.

In the detailed description of the invention we distinguish three conceptual blocks that comprise the component parts of the device: the transmitter and modulator, the receiver with rectifier and filters, and finally, the demodulator that could be included as a part of the receiver.

1- The proposed transmitter is described in the scheme of Figure 1. This component is based on an E-class amplifier in which the carrier of the signal to be transmitted is introduced by the amplifier element that is the transistor (MC). The amplifier's resonant circuit is composed of CT capacity and LT inductance. The modulation is carried out by inserting a connected CMod capacitor in the resonant circuit through a switch implemented with a transistor (MMod). The block (E) is responsible for generating all control signals, that is, the carrier (P), the data (I) and the power control (W). Internally this block (E) is manufactured with an FPGA that generates the carrier (P) with a square signal of fixed frequency and the data (I) to be transmitted as a set of ones and zeros corresponding to the digital coding of the information to be transmitted . Similarly, block (E) will generate the control signal of block (D) that controls the transmitter power. The data (I) is applied directly to the modulator (MMod) and depending on the data to be transmitted it will insert the capacity, MMod, (1 logical) or not (0 logical). The effect obtained by connecting the capacitor in the resonant circuit is that the frequency response of the capacitor and the ability to transmit energy are modified. The modulator used in the external transmitter is based on the fact that the carrier remains constant and it is the resonant circuit that is modified causing a change in the transfer function when introducing or eliminating the CMod, also modifying the ability of the resonant circuit to transmit Energy. The result is that two levels are sent for the same carrier and signal to be transmitted that allow the transmission of the information. The advantage of this system is that when modulating with non-dissipative elements (which do not consume) such as capacitors and / or inductances, this does not dissipate and therefore the efficiency in energy transmission is greater than those proposed by the state Of art. In addition, since the modulation is not performed on the carrier, it is possible to include a transmission power control that is performed by a module (D) that is responsible for the power supply and therefore the level of the transmitted signal. The module (D) is a DC / DC step up converter that determines the level of power to be transmitted based on the control signal (W).

2- The proposed receiver is described in the scheme of Figure 2 where the elements that compose it are distinguished: the resonant receiver circuit (H) implemented with the inductance LR and the CR capacity, the rectifier circuit formed by (Dl, D2) , the continuous filter (Cl, C2), the demodulator (K) and the load (RL) that will be the final device or application. The CR capability will be used to adjust the tuning and / or resonant frequency of the receiver circuit and optimize the efficiency in energy reception. For rectification, two high-value capacities are used, arranged in series with that of tuning (Cl, C2 »CR for example a factor 10) so that the resulting capacity is approximately CR, so the response of the resonant circuit will not be modified. If these capacities (Cl, C2) are used for filtering after rectification, a good continuous component is obtained while the resonant circuit is minimally altered maintaining efficiency in the reception of energy and / or data. In order to obtain sufficient energy to power the device or application, a rectifier formed by diodes DI and D2, which circulate the current from the inductance LR through the capacitors Cl, C2 respectively depending on the direction of flow of the current, so that Cl will be charged with a polarity while C2 is charged with the opposite. If the Gnd terminal is defined as the most negative and the opposite in the other capacitor (U) as the most positive, a rectification with filtering is obtained, this filtered voltage can be used as a power supply for the load. The advantage of the proposed structure is that the current flows more time through the diodes by storing a greater load on the capacitors and consequently optimizing the efficiency of the rectifier and the ability to receive energy. At the same time, it minimizes the effects on the resonant circuit and maintains the modulation index in the received signal which facilitates the process of demodulation of the information. The proposed structure It allows a serial configuration between the load and the receiver resonant circuit with the particularity that the receiver is more efficient, when the load increases (consumption increases). Another advantage to note is that increasing the load or modifying the coupling does not change the resonant frequency so it is not necessary a resintonia of the receiver resonant circuit.

3- To obtain the data sent by the transmitter, a demodulator is available. The diagram shown in Figure 3 shows the demodulator (K) together with the connection, through the capacitor (CExt) to the resonant circuit that includes the total load equivalent to the application. The CExt capacitor is of lower value than CR to minimize the effects on the tuning capacity of the receiver (CR). The receiver configuration allows to obtain very good modulation rates because the signal is little affected by the rectifier. As a result, the input signal can be high and therefore a voltage divider implemented with the capacitors CExt, and CInt has been arranged, obtaining a voltage that can be used by the demodulator without danger of damaging it. In order to obtain the carrier and to be able to use it as an application clock, two Ml diodes, M2 (for example implemented with MOS transistors) have been used to take advantage of the characteristic voltage current, and obtain a higher voltage for a small passage of current from of the voltage divider (CExt, CInt). The characteristic voltage current allows to obtain a high voltage for a relatively small current and superior to that of a resistance since the curve is exponential, so if a comparator (S) is arranged between the ends of the diodes Ml, M2, a The comparator output will obtain the clock signal (C). The diodes are in a configuration opposite each other to allow the passage of current in both directions of the input signal. The second advantage of the diodes and their exponential characteristic is that it limits the input range and prevents high voltages from being obtained that could damage the other stages of the demodulator (K). To recover the information, a detector made with an MRec transistor is available that performs two functions:

a) - Rectification function with the non-linear characteristic of the device itself, and, b) decrease or attenuation of the output impedance of the detector when using the low impedance characteristic of the transistor, this allows CIf, Rl to constitute the Low pass filter that defines the upper cutoff frequency to limit the bandwidth of the received data and that C2f, R3, C3f implement the high pass filter feature, also depending on the speed of the data. In order to facilitate the design of the filter, it is considered that C2f, C3f and R3 must be much larger than CIf, Rl so that they do not affect the low pass filter. Finally, in order to obtain the digital signal corresponding to the output data, a comparator with hysteresis (T) is available, which will eliminate errors due to noise.

With the assembly proposed here, the following advantages are obtained: 1- The transmitter can be optimized for the signal to be transmitted because the signal is not modulated, the transmitter amplifier being more efficient and allowing the control of the transmitted power through the level of the signal for being independent of the modulator,

2- The modulator does not depend on the time constant of the power supply, which turns out to be proportional to the level of the signal, allows higher speeds of data transmission without decreasing the efficiency of the transmitter since it is independent, and,

3- When modulating the capacity of energy transmission by means of components that do not dissipate power (inductances and capacities) the modulator does not consume and the efficiency in the transmission of energy is optimal and better than that of the devices used until now.

Next to the transmitter a receiver based on a resonant system with a rectifier and demodulator is proposed to obtain the information. The proposed rectifier allows a series configuration with the resonant circuit allowing the signal obtained does not change its shape, this makes the modulation index is maintained and demodulation easier, thus being able to obtain higher transmission speeds and reduce The complexity of the demodulator. Another characteristic obtained by using this system with a serial configuration is that it is more optimal when the load increases, that is, when the consumption increases. In this way the transmission and reception efficiency is optimized, in addition to the modification of the coupling either due to the modification of the distance or misalignment, etc. does not modify the response in the data transmission, nor the need to re-tune the receiver and / or transmitter, since both continue to be in resonance since the resonance frequency is independent of these parameters. It should also be noted that the rectifier allows to obtain the energy induced in the coil for a longer time since it takes advantage of both half-cycles of the received wave, so that the rectification is more efficient and therefore the possibility of applying the received energy to the load, reducing the losses in the receiver and the power required in the transmitter.

The receiver may also include a demodulator that is used to retrieve transmitted information. The proposed demodulator is capable of processing an OOK signal and recovering the carrier that can be used in the receiver as a system clock in the case of having a digital block. The demodulator is characterized by being applied in such a way that it does not alter the response of the system or decrease the efficiency in obtaining energy, this happens because it is coupled directly to the coil with a capacity much lower than the tuning capacity, this being sufficient for operate said demodulator and not to affect the resonant circuit, rectifier, filter and load. That same element of the circuit is also provided with a filter that is applied according to the bandwidth defined by the data and the transmission speed to allow a better reception and greater immunity to variations in the level of the signal and / or interference.

Legend of the figures.

Figure 1. Diagram of the assembly of an inductive transmitter and modulator proposed in the present patent document consisting of: D - Power control, E - Signal generator, F-Transmitter amplifier, G - modulator, P - Signal corresponding to the carrier frequency, Lchoque - Shock coil, M _c - Transistor amplifier, C _T - Tuning capacitor, CMod - Capacitor for modulation, MMod - Transistor acting as switch to produce data modulation, Lj - Transmitter coil for energy and data, I - Data to be transmitted and W - It is a signal used for power control in the transmitter.

Figure 2. Diagram of the assembly of an inductive receiver proposed in this patent document consisting of: H - Resonant system, R - Rectifier, J - Load, K - Demodulator, C and V - Digital signals of the carrier and data , L _R - Coil Receiver, C _EXÍ - External voltage divider capacitor, C _R - Receiver tuning count, Di and D ₂ - Rectifier diodes, Ci and C ₂ - Continuous filter capacitors.

Figure 3. Diagram of the assembly of the receiver system with demodulator proposed in this patent document consisting of: H - Resonant system, L _R - Receiving coil, C _R - Tuning capacitor, R _L - Equivalent load, L - Attenuator voltage formed by the capacitors CE _X Í and C _ln t, Mi and M ₂ - Diodes implemented with MOS transistors, Rβias - Polarization resistance, S - Comparator to extract the digital clock, K - Demodulator, M _Rec - Information detector, d _f - Low pass filter capacitor, Ri - Low pass filter resistance, C ₂ f and C ₃ f - High pass filter capacitors, R ₃ - High pass filter resistance, M - Band pass filter, V - Corresponding digital signal to the received data, T - Comparator with hysteresis, C - Clock signal of the same frequency as the carrier. Figure 4. Block diagram of the inductive telemetry system environment proposed in the invention and consisting of: A - External unit, X - External controller, Y - Application, B - Internal unit, Tx - External transmitter, Z - Corresponding system to the invention and Rx - Internal receiver.

Figure 5. Results obtained in the device presented in example 1, of the transmission of information at a speed of 1 Mbps, with a modulation index of 25% and at a distance of 3 cm. The meaning of the traces is: trace 1 indicates the transmitted signal (O), trace 2 is the received signal (Q), trace 3 corresponds to the received data (V) and trace 4 is the transmitted data (I).

EXAMPLE OF EMBODIMENT OF THE INVENTION. The invented device can be applied to any electronic system consisting of two units A and B, as shown in the diagram of Figure 4. In this image A represents the external unit (to which access is provided) comprising the controller external (X) and the transmitter (Tx) and B is the internal unit that is in an isolated and / or airtight medium and will consist of the receiver (Rx) and is also the application (Y) to be controlled. The inductive telemetry system is the invention (Z) of the present patent which consists of two modules, the Tx that is inside the external unit (A) and the Rx that is in the internal unit (B). The example presented is a particular application of the device described in the previous section. The telemetry method chosen in an implantable electrical stimulator consisting of an external controller (X), a stimulator or application (Y) and the invention that is the subject of this patent or telemetry system (Z). The telemetry system consists of the transmitter (Tx) and receiver (Rx) unit. The results obtained with this particular device are shown in Figure 5.

In this case the transmitter (Tx) is composed of the following elements: The control signal generator (E) is manufactured with an FPGA (EP 1C6) that generates the 8 MHz carrier signal (P), the data (I) with a speed of 1 Mbps (mega bits per second) and the power control signal (W). As amplifier element (MC) the transistor ZVN2106G is used, for the shock coil (LCh) an inductance of 200 uH is used, the tuning capacitor (CT) is a capacitor variable between 6 and 8OpF to make a fine adjustment taking into account It counts the parasitic effect of the printed circuit tracks and the tolerance of the components used. For modulation a capacitor (CMod) variable of 6 and 80 pF has been used that will allow to adjust the value of the modulation index according to the response of the global system and as a switch (MMod) a transistor ZVN2106G. The transmitter coil (LT) has been made with 0.5mm thick copper wire with 10 turns and 2.5cm diameter, obtaining a value of 7.5 microH.

For the receiver block (Rx) there is a resonator system (H) made with a coil (LR) and a capacitor (CR) whose values will be determined by the resonance frequency of the system that will be 8MHz. In this case the value of LR and CR will be similar to those used in the transmitter and its specific value will be adjusted at the time of assembly to ensure the tuning of the receiver resonant circuit. The rectifier block (R) has been made with two schottky diodes that allow the configuration proposed in the invention of the diodes Dl and D2 with the BAT54S component. Schottky diodes are chosen because they improve rectifier performance by being faster. The Cl, C2 capacitors have been chosen of 2.2 microF considering that they can be found with a relatively small size (SMD-0805) and the value is almost 5 orders of magnitude greater than CR (approximately 68pF) which guarantees that the Resonance frequency is not affected. The demodulator (K) has been designed with an integrated circuit (ASIC). For the CExt capacitor, a 3pF SMD 0305 capacitor is used being sufficient for the implementation of the voltage divider without modifying the resonance frequency of the block (H). The other components of the demodulator are integrated in the ASIC with a CMOS technology. The diodes to improve the response of the carrier detector have been made with a pair of NMOS and PMOS transistors (Ml and M2) that allows the current to pass in both half-cycles of the signal. For the detection of the carrier a high speed comparator has been provided that allows the detection of mV signals up to frequencies of 30MHz, this allows the same system to be used in a greater range of carrier frequencies, useful in systems where Receiver inductances are smaller. For the detection of the signal, a rectifier implemented with an NMOS transistor (MRec) has been provided, which allows the signal to be rectified and at the same time lower the impedance as a result of the output being obtained by supplier. Following the rectifier, a low-pass filter implemented by CIf, Rl, which sets the upper cut-off frequency in the detection of the data has been arranged, this is useful to avoid that the noise of the rectifier or the power supply could introduce errors in the detection of the information. It has also included a high pass filter implemented with C2f, C3f, R3 that allows to eliminate the offset of the previous stages and adapt the level to facilitate detection. Finally the detection is performed with a comparator with hysteresis that reduces the possibility of errors due to noise.

Some results to be highlighted in relation to the new structure presented to send energy and information at a certain distance in the absence of a physical connection between the transmitting element and the receiver are: 1) the efficiency (Ef) achieved in the transmission of energy, for a distance of 2 cm, it reaches 50% when the systems of the prior art do not exceed 20% for 1 cm and 2) the modulation indicator (IM) the value set by the transmitter is maintained up to a speed in the data transmission of 1 Mbps and a distance of 3cm, while in the state of the art the data speed is around 100 kbps. The results achieved in the case of a transfer of 1 Mbps at a distance of 3 cm with a modulation index of approximately 25% are shown in Figure 5 where trace 1 indicates the transmitted signal (O), trace 2 is the received signal (Q), trace 3 corresponds to the received data (V) and trace 4 is the transmitted data (I).

Claims

CLAIMS.

1) Telemetry device in inductive mode for remote transmission and reception of electromagnetic energy and information.

2) Inductive mode telemetry device mentioned in the preceding claim in which the transmitted electromagnetic energy is fully controllable at any time during its operation.

3) Inductive mode telemetry device mentioned in claims 1 and 2 which is composed of the following parts; transmitter, receiver and modulator.

4) The transmitter mentioned in the preceding claim, 3, is characterized by the following: a) Having a new structure for the modulator that implements an OOK (On-Off-Keying) coding by modulating the resonance of the transmitter system, being the modification of the energy transmission capacity of the resonant system which achieves the required transmission levels and therefore the modulation of the carrier based on the data. b) The transmitter is made of non-dissipative components, therefore losses are reduced and efficiency is improved. c) The proposed control of the modulation of the transmitted signal is characterized by a higher data transfer rate without reduced energy transmission efficiency. d) The new transmitter proposed in this patent, thanks to the type of modulation achieved, allows the control of the transmitted energy given that when said modulation is not carried out directly in the signal but in the transmission capacity, the functional independence of the Modulation and transmitted power. e) The design of the transmitting unit that provides the variation of the transmission capacity of the electromagnetic energy allows a higher transfer rate as it is not affected by the response of the power or power regulation circuit of said transmitter, since these are functionally independent.

5) The electromagnetic energy receiver mentioned in claim 2, is characterized by: a) It allows efficient rectification of the signal, without reduction in the ability to receive signals in which data to be sent remotely is encoded. b) Connect the load in series with the electromagnetic energy reception circuit. c) It has a circuit that allows the rectification of energy in a serial configuration with the receiver resonant circuit. This allows the reception of energy without reducing the level of modulation. d) The topology designed for the rectifier, configuring the load in series with the resonance circuit optimizes efficiency without increasing the consumption of the device. e) By allowing the serial configuration, the tuning of the receiver is not altered by a modification of the coupling or the load, keeping the tuning always in any condition. f) By design neither the continuous signal rectification circuit, nor the load, nor the filtering that the load may have, modify the response of the receiver thus allowing the signal to be of greater power while obtaining higher speeds of data transmission, g) When the modulation index of the signal in the receiver is not modified, it is easier to demodulate by means of an additional circuit that allows decoupling and directing it to the demodulation unit, h) The rectifier of the receiving unit has a configuration that allows the flow of current in both directions so that the receiver resonant circuit is minimally altered thus obtaining better responses in the reception, of the energy and of the data sent. i) The efficiency of the rectifier is greater by forcing the coil current to flow in both directions through the rectifier and therefore that all the energy received by the inductance is applied to the load. j) The new structure of this unit allows the time in which the signal is rectified to be longer, obtaining better energy levels and therefore increasing efficiency.

6) The receiver physically incorporates the demodulator so that the received energy can be used to control the internal device. Said demodulator is further characterized by: a) Being constituted by a very small capacity in order to minimize any modification of the performance of the resonant receiver circuit. b) Includes a non-linear system that allows greater sensitivity and limits the damage of the input circuit. c) Includes a carrier recovery circuit that can be used as a reference clock for any digital circuit included in the application. d) It incorporates a bandwidth demodulator defined by the speed of transmission of information allowing data to be recovered, reducing errors due to variations in the level of the received signal. e) Use a comparator with hysteresis to reduce the error in the detection by noise in the signal or in the circuit power.

7) Any other telemetry device in inductive mode for remote transmission and reception of electromagnetic energy and information resulting from the modification of the units and elements described herein and mentioned in claims 1, 2, 3, 4, 5 and 6