Acoustic transmission system, primary circuit, secondary circuit, transmission method and method for using an acoustic transmission system

Abstract

To provide an acoustic transmission system capable of overcoming a corresponding barrier without impairing the function of the barrier which does not transmit electromagnetic waves.SOLUTION: The acoustic transmission system capable of exchanging information with a volume sealed and / or separated by a barrier opaque to electromagnetic waves includes a primary side S1 having a transmission unit SE, a reception unit EE, and an electroacoustic transducer EAW, and a secondary side S2 having a transponder TP and the electroacoustic transducer EAW.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the transmission of energy and / or information through gas-tight and / or galvanic barriers. In particular, the present invention relates to an associated transmission system using acoustic waves, a primary circuit therefor, a secondary circuit therefor, a method for transmitting information and / or energy across a barrier, and the use of the corresponding acoustic transmission system. [Background technology]

[0002] There is a need to be able to capture and control industrial processes. The problem is to capture and control processes that are difficult to capture with conventional measurement techniques. In industrial, aviation, and marine applications, there are examples where the measurement space, which determines the parameters to be measured, is delimited by a barrier. Pressure vessels and generally closed structures can also be considered as barriers. In particular, barriers that are hermetically sealed and / or impermeable to electromagnetic waves are of interest.

[0003] Particularly problematic are barriers that do not allow or require drilling to insert a sensor into the space to be measured.

[0004] It is known that acoustic waves can pass through corresponding barriers. For example, an electroacoustic transducer is known from US 5,594,705 A. A corresponding transmission assembly is described, for example, in the review article by Ding-Xin Yang, Zheng Hu, Hong Zhao, Hai-Feng Hu, Yun-Zhe Sun and Bao-Jian Hou: "Through-Metal-Wall Power Delivery and Data Transmission for Enclosed Sensors: A Review", Sensors 2015, 15, 31581-31605, https: / / www.ncbi.nlm.nih.gov / pmc / articles / PMC4721790 / . The use of acoustic waves for power transmission is known from the paper "State-of-the-Art Developments of Acoustic Energy Transfer" (Md Rabiul Awal, Muzammil Jusoh, Thennarasan Sabapathy, Muhammad Ramlee Kamarudin, and Rosemizi Abd Rahim; International Journal of Antennas and Propagation, Volume 2016, Article ID 3072528, Hindawi Publishing Corporation, https: / / www.researchgate.net / publication / 307893860_State-of-the-Art_Developments_of_Acoustic_Energy_Transfer). For example, DE102007038419B4 discloses a sensor system in a metal housing that can be supplied with energy from the outside by ultrasound and that can also transmit sensor data by ultrasound. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent Publication No. 5,594,705 [Patent Document 2] German Patent Registration No. 102007038419 Summary of the Invention

[0006] Therefore, there is a need for improved transmission systems that can overcome the corresponding barriers without impairing the function of the barriers.

[0007] For this purpose, an acoustic transmission system is provided according to the independent claims. The dependent claims disclose advantageous embodiments of the system, advantageous primary circuits, secondary circuits and methods, and advantageous uses of the transmission system.

[0008] The transmission system includes a transmitting unit, a receiving unit, and an electro-acoustic transducer on a primary side. The transmitting unit is designed and adapted to provide a transmitting signal. The receiving unit is positioned and adapted to receive a receiving signal in response to the transmitting signal. The electro-acoustic transducer is positioned and adapted to convert the transmitting signal into an acoustic signal and convert the acoustic signal into a receiving signal. The transmission system further includes a transponder and an electro-acoustic transducer on a secondary side. The transponder is designed and adapted to receive the receiving signal and to transmit the transmitting signal, thereby enabling the electro-acoustic transducer on the secondary side to be in acoustic contact with the electro-acoustic transducer on the primary side. The acoustic transmission system further includes a medium between the primary side and the secondary side that is transparent to the acoustic signal.

[0009] Essentially, a medium is a barrier that must be overcome to exchange information between the two sides of the barrier. The barrier is opaque to electromagnetic waves and can hermetically separate the outside and the inside from each other. Each of the two electroacoustic transducers in the transmission system can be a piezoelectric transducer. A piezoelectric transducer can have a piezoelectric element and an electrode structure. The piezoelectric element converts electric signals into acoustic signals and vice versa due to the piezoelectric effect. Transducers operating with longitudinal acoustic waves usually have a sandwich structure in which a piezoelectric element is placed between a lower electrode and an upper electrode. When combined with a suitable acoustic termination, this electroacoustic transducer can be operated as an electroacoustic resonator.

[0010] It is also possible for the transmission system to include a sensor on the secondary side.

[0011] The sensor can be a temperature sensor, a pressure sensor, a humidity sensor, a gas sensor, a light sensor, a pulse counter, a microphone or a similar type of sensor. In particular, the sensor can be a MEMS sensor (MEMS = micro electromechanical system). Such sensors are characterized by being cost-effective to mass-produce, having good electrical properties, a good signal-to-noise ratio and low power consumption.

[0012] It is possible that the transmission system includes logic circuits on the secondary side.

[0013] A logic circuit can be connected to the sensor and can drive and control the sensor, perform readout, and possibly provide the necessary bias voltage for the sensor. The logic circuit can detect the sensor signal. The sensor signal is usually an analog sensor signal. Therefore, if a digital output signal is required, the logic circuit can have an A / D converter and amplify the strength of the sensor output signal.

[0014] For communication with the primary side, the secondary side of the transmission system can have a modulator, which can be, for example, a MOSFET (metal oxide semiconductor field effect transistor), which can code a signal from the secondary side to the primary side, for example, to indicate the measured value of a corresponding sensor.

[0015] The modulation can be amplitude modulation, frequency modulation, phase modulation, or a composite modulation that combines the above different modulation forms. Switching the amplitude on and off in response to the primary is a special form of amplitude modulation.

[0016] It is further possible for the secondary side to have a corresponding modulator for modulating the electrical load of the secondary side electro-acoustic transducer.

[0017] Modulating the electrical load of the secondary electroacoustic transducer is a preferred embodiment, particularly since it can be implemented as an energy-saving circuit. An electrical load is connected to the secondary electroacoustic transducer, the impedance of which can be varied by a modulator. When the secondary side, i.e., the secondary electroacoustic resonator, receives acoustic waves that have passed through the barrier from the primary side, the secondary electroacoustic transducer converts the acoustic signals into electrical signals. These electrical signals are applied to the secondary electrical load. The system consisting of the secondary electroacoustic transducer and its connected impedance-adjustable electrical load acts as an acoustic wave reflector whose reflection coefficient can be adjusted by adjusting the electrical load. In this way, modulating the electrical load of the secondary electroacoustic resonator modulates the reflection factor of the acoustic wave. The modulated acoustic waves can be received on the primary side in accordance with the modulation of the reflection factor and evaluated accordingly.

[0018] When modulating the reflection factor by modulating the electrical load, no special wave excitation is required on the secondary side of the transmission system, and therefore the corresponding energy consumption on the secondary side for communication with the primary side is minimized.

[0019] The energy consumption on the secondary side can be small enough that the energy transporting the acoustic waves from the primary side to the secondary side is sufficient to power the secondary side circuit elements. Electrical energy can be easily obtained from the acoustic energy on the primary side via an electro-acoustic transducer.

[0020] For this purpose, the transmission system may have a rectifier on the secondary side, and the output current and voltage corresponding to the electro-acoustic transducer on the secondary side may be supplied as a DC voltage on the secondary side, using a smoothing capacitor if necessary.

[0021] A rectifier may be connected between the electro-acoustic transducer and the modulator. Alternatively or additionally, the rectifier may be connected directly to the modulator.

[0022] Placing the modulator, for example in the form of a MOSFET transistor, immediately after the rectifier has the advantage, in contrast to the circuit of US 5,594,705, that the voltage drop across the rectifier is small so that the input carrier frequency from the primary side is not reduced to 0 volts by the digital switch modulator, for example a transistor, during load modulation. A residual voltage of this carrier frequency, which may be for example of the order of 100 mV, can be used by the secondary circuit to obtain a clock signal in the secondary circuit during this communication period.

[0023] The transmission system may also comprise a transistor whose base is connected to the load modulation terminal.

[0024] It is possible that the transistor is the MOSFET described above.

[0025] The transmission system may have a rectifier between the electro-acoustic transducer and the transistor, such as the rectifier described above, which makes it possible to prevent the voltage at the electro-acoustic transducer from going to zero during load modulation even if the transistor is short-circuited.

[0026] It is therefore also possible to derive the clock on the secondary side from an incident acoustic wave with a carrier frequency on the primary side during modulation.

[0027] The transmission system may also have an intermediate energy storage on the secondary side. The intermediate energy storage may comprise a capacitor and / or an accumulator. This allows the intermediate energy storage to store energy required for less frequent measurement processes, such as measurement processes using an arc between two electrodes. Depending on the energy transmitted from the primary side that is available for measurement on the secondary side and the frequency at which measurements are to be made on the secondary side, the available energy for each measurement process is essentially specified.

[0028] The transponder may be intended and suitable to use the clock of the receiving system as its system clock, whereby the receiving system receives the clock of the acoustic wave transmitted by the primary side to the secondary side through the barrier.

[0029] Therefore, unlike conventional information transmission systems, the secondary side does not require an oscillator as a clock generator for the digital circuit, which can save energy used for measurement.

[0030] Correspondingly, it is also conceivable that there is no oscillator for return communication on the secondary side.

[0031] Furthermore, since the clock of the signal received from the primary side can also be used for other circuit components on the secondary side, there may be no oscillator at all as a clock generator on the secondary side.

[0032] The transmission system may include an electrical impedance matching network on the secondary side.

[0033] The electrical impedance matching network serves to match the electrical impedance between the output impedance of the electro-acoustic transducer on the secondary side and other circuit components on the secondary side.

[0034] The impedance matching network can include appropriately connected capacitive, inductive, and resistive circuit elements.

[0035] The transmission system may include a frequency reducer on the secondary side.

[0036] A frequency reducer includes a circuit that converts a signal having an input frequency into an output signal having an output frequency that is different from the frequency of the input signal.

[0037] The return communication with the primary side can essentially be based on a reduced frequency as a carrier frequency, so that on the primary side the response signal can be easily separated from the primary signal and evaluated by a crossover.

[0038] In particular, a frequency halving circuit or a cascade of frequency halving circuits can be used as a frequency reducer. For example, a sequence of 1, 2, 3, or 4 frequency halvings can reduce the frequency of the carrier signal from the primary by half, quarter, eighth, or sixteenth. If the reduced frequency is sufficiently different from the primary frequency, the crossover of the primary can be isolated from the secondary, even though the strength of the response is greatly attenuated.

[0039] The transmission system may include, on the secondary side, a circuit unit having a transformer and a parallel circuit including an inductive element, a capacitive element, and a logic circuit.

[0040] The inductive and capacitive elements can thereby provide electrical impedance matching, possibly in conjunction with a transformer.

[0041] Logic circuits are used to drive and control the sensor and modulate the signal for response to the primary as needed.

[0042] The transmission system may include, on the secondary side, a port, a supply terminal, four circuit nodes A, B, C, and D, and a logic circuit front-end circuit having an operational amplifier and seven transistors.

[0043] These circuit components can represent circuit components of an integrated circuit as a variant of the transponder circuit for load modulation, with one of the transistors in particular performing the actual load modulation.

[0044] On the primary side and / or the secondary side, acoustic and / or electrical impedance matching can be performed and related means can be provided.

[0045] In particular, electrical impedance matching can be performed only on the primary side, or electrical impedance matching can be performed only on the secondary side, or acoustic impedance matching can be performed only on the primary side or only on the secondary side.

[0046] However, it is also possible and advantageous if both the primary and secondary sides have electrical impedance matching, and correspondingly, it is also advantageous if both the primary and secondary sides have acoustic impedance matching.

[0047] Electrical impedance matching can be achieved via a conventional electrical network having active or passive circuit elements, such as capacitive, inductive, or resistive elements. Acoustic impedance matching is possible via an additional layer with adjusted acoustic impedance. For example, an additional layer can be disposed between the primary electro-acoustic transducer and the barrier material, or between the barrier material and the secondary electro-acoustic transducer.

[0048] In an advantageous embodiment, the corresponding electro-acoustic transducer is mechanically coupled to the barrier by means of an adhesive layer, for example a suitable adhesive, which has a suitable acoustic impedance or a layer thickness that is as thin as possible.

[0049] Furthermore, it is possible to have a frequency splitter on the primary side, as mentioned above.

[0050] A frequency demultiplexer can be used to separate the secondary response from the primary carrier signal and evaluate it without being disturbed by the primary signal strength.

[0051] The frequency splitter can preferably comprise a diplexer or a duplexer. If the secondary side does not comprise a frequency reducer but a frequency booster, for example one or more frequency doublers, the primary side can also split off and evaluate signals with frequencies equal to or greater than the frequency of the primary signal.

[0052] It is also possible that in the transmission system the primary side is intended and suitable for continuously supplying energy to the secondary side, the energy being transmitted through the barrier, preferably in the form of acoustic energy, and converted into electrical energy on the secondary side, for example by means of an electro-acoustic transducer.

[0053] Communication can only occur one way, from the secondary to the primary, in which case the primary only transfers energy to the secondary.

[0054] However, it is advantageous if the transmission system is intended and suitable for two-way communication, so that the primary side can transmit information to the secondary side, and the secondary side can receive and evaluate the information.

[0055] Furthermore, the secondary side can transmit information to the primary side, and the primary side can evaluate the received information. Furthermore, it is also possible for the transmission system to have a matching network on the primary side, which has two signal lines, a balanced guided signal input, an unbalanced guided signal output, a power supply connection, three inductive elements, and six capacitive elements.

[0056] The matching network can receive information from an external circuit environment via a balanced guided signal input, and via an unbalanced guided signal output, the primary matching network can transfer the corresponding received information to the external circuit environment.

[0057] In a balanced guided signal line, there are two conductor elements that carry the same signal but with opposite amplitudes. Balanced signal lines are relatively immune to common-mode interference.

[0058] Means for recording and transmitting audiovisual perceptions can also be included as "internal" (secondary) applications in the transmission system (e.g., audio recording, image recording, video recording, image and audio recording, i.e., for example, a "classical" video camera).

[0059] These can be operated with the help of energy "harvested" from a signal introduced on the primary side, for example an ultrasonic signal, as already explained for the other sensors.

[0060] The data recorded internally, i.e., for example, sound, images, video, sound-image-video, etc., can be transmitted again via acoustic waves in the form of digital data to the "outside", i.e., primary side, as user data of the described transmission system.

[0061] In principle, monochrome, grayscale or color images can be transmitted.

[0062] You can choose between mono and stereo audio.

[0063] In other words, any type of transmission common to such can be selected.

[0064] Overall, the specific choices are limited only by bandwidth and transmission rate.

[0065] However, what is particularly important when transmitting images or videos is the mechanism that transmits the start of a new image or the start of a new image line (when scanning dots or lines) to the primary side in order to display the transmitted image correctly.

[0066] To further complicate things, typically three values ​​or data vectors (red, green, blue) can be transmitted for each pixel in a color image. This information must be properly adapted to the data frame size provided by the hardware.

[0067] In particular, the hardware may support data frames of, for example, 64-bit size, which may, on the one hand, be filled with processed image data and, on the other hand, these data frames may be passed to the outside via a medium between the secondary side and the primary side.

[0068] The primary circuit may be designed as or include a detachable or portable module, which may include an NFC antenna and / or a piezoelectric transducer element.

[0069] In this way, an NFC interface, such as a mobile phone, can be used to control or activate a secondary application via acoustic waves.

[0070] This means that the transmission system can include further air interfaces or the transmission system can be easily expanded.

[0071] In this way, the transmission system can be extended or extensible by "relays" including transceivers of any wireless standard (e.g. Bluetooth®), piezoelectric transducers, energy storage (batteries or rechargeable accumulators) and electronics suitable for data conversion between different standards.

[0072] A primary circuit, e.g., a primary circuit of a transmission system, may include primary elements as described above. Correspondingly, a secondary circuit may include elements of the secondary side of the transmission system as described above.

[0073] The method of transmission using the acoustic transmission system may include the following steps: - transmitting a carrier signal to a secondary receiving unit using a primary transmitting unit; - receiving a carrier signal via a receiving unit; - generating a response signal based on the measurements; - transmitting a response signal to the primary side; Includes:

[0074] The communication may further include a step for identifying a secondary part. The identification may be based on measurements. It is also possible to use other information, such as additional information, for the identification. The identification system may also include multiple secondary parts.

[0075] To achieve this, the primary side can output a continuous sinusoidal signal at or near the carrier frequency. This sinusoidal signal can be used by the secondary side to continuously draw power from volatile storage to maintain operation. Additionally, the primary side can sporadically modulate this continuous sinusoidal signal to transmit commands and / or values ​​for identification.

[0076] The secondary side, on the other hand, typically presents a particular load impedance to the converter continuously, which is then sporadically modulated for data transmission.

[0077] A change in the (electrical) load of the secondary piezoelectric transducer can cause a change in the (electrical) impedance of the primary piezoelectric transducer, and therefore a modulation of the secondary can be perceived on the primary side.

[0078] This modulation is advantageously performed on the secondary side so that power (on the secondary side) can be continuously derived from the carrier sine wave signal generated on the primary side.

[0079] On the primary side, a continuous sinusoidal signal for load modulation can be generated and the change in the connection impedance of the primary side piezoelectric transducer can be continuously determined or measured.

[0080] The primary signal source can be a current source, and a change in the electrical load resistance of the current source results in a change in voltage across the load resistance. This voltage can be measured by a reader and evaluated (i.e., the primary reads and evaluates the acoustic response signal from the secondary).

[0081] The primary and secondary sides may be hermetically and / or separated by an electromagnetic signal impenetrable barrier.

[0082] Acoustic waves are capable of transmitting information and / or energy through a barrier between the primary and secondary sides.

[0083] Additionally, communications between the primary and secondary sides and / or between the secondary and primary sides may be encrypted point-to-point.

[0084] The encryption method can be any common encryption method, which allows point-to-point encryption, which can be implemented in any case as an additional security feature.

[0085] The communication may use encryption methods.

[0086] This ensures that the content of the communication cannot be accessed by third parties and / or specifically cannot be altered by third parties. In this respect, encryption is distinguished from procedures for detecting transmission errors.

[0087] However, the data transmission itself may also incorporate the possibility of detecting transmission errors, for example by mechanisms using parity bits and / or the possibility of detecting and / or correcting individual transmission errors within a data frame, for example by mechanisms using a cyclic redundancy check (CRC), e.g. CRC16 or CRC32.

[0088] Data encryption, error protection and error detection each represent different aspects and can be performed individually or in combination.

[0089] Communication can be one-way or two-way via digital signals.

[0090] Communication can be one-way or two-way.

[0091] In the case of two-way communication, this can occur simultaneously (full duplex, e.g. frequency duplex, FDD) and / or sequentially at defined times without communication (half duplex, e.g. time division duplex, TDD). Information is transmitted by modulation, which can be chosen from load modulation, amplitude modulation, phase modulation, frequency modulation and complex modulation with a hybrid of two or more of the above modulations.

[0092] In particular, modulation can be applied in the data flow direction from the primary side to the secondary side. Any single modulation in sections 8 and 9 of ISO / IEC 14443-2_2010 (i.e., ISO / IEC 14443-2 as amended in 2010) can be used as the modulation.

[0093] Additionally, the communication method may use error detection or correction methods.

[0094] In particular, data packets, for example data frames (frames), can be sent from the primary side to the secondary side as needed and responded to accordingly and only as needed from the secondary side.

[0095] Between such asynchronous data frames, it is possible for only unmodulated carrier frequency to be transmitted from the primary side to the secondary side, ie for periods of time without data frames to follow.

[0096] It is also possible to transmit a parity bit between 8 bits of user data in accordance with standard ISO / IEC14443-3_2011 (standard ISO / IEC14443-2 amended in 2011).

[0097] Additionally, they may be transmitted using a Cyclic Redundancy Check (CRC) mechanism.

[0098] The cyclic redundancy check (CRC) is based on the standard ISO / IEC 14443-3_2011 and can use a CRC16 or CRC32 check. The last 2x8 bits or 4x8 bits belong to the check.

[0099] There is a possibility that the secondary side temporarily stores the energy it receives from the primary side.

[0100] Sound waves passing through a solid barrier can at least potentially be used to communicate through the barrier.

[0101] It is possible to control the communication via the primary side, which can also be described as the "primary side speaks first" principle.

[0102] It is possible for one primary side to communicate with multiple secondaries. Thus, on the other side of the barrier, multiple sensors, each with its own energy and information transmission system, can communicate with the primary side.

[0103] Furthermore, in this method it is possible to use anti-collision methods to avoid overlapping of the signals of the various secondary sides.

[0104] Communication may involve acoustic signals with frequencies ranging from 1 MHz to 50 MHz.

[0105] The preferred frequency will depend on the geometry and materials used for the barrier and the corresponding acoustic impedance of the materials used.

[0106] The barrier is 4mm thick, the barrier material is made of metal with a density of 7890kg / m^3 and a sound speed of 5970m / s, and it has been shown that communication is sufficient at frequencies of 9.4MHz, 9.9-10.1MHz, and 10.7MHz.

[0107] In principle, a narrow but sufficiently wide usable frequency range results from resonances determined by the thickness of the metal plate.

[0108] On the other hand, a relatively wide usable frequency band is obtained due to the resonance determined by the dimensions of the primary acoustic transducer, for example the thickness of the piezoelectric disc.

[0109] This also includes the method of attaching the piezoelectric disk (by adhesive, etc.).

[0110] A certain bandwidth is required to transmit the reader's modulated signal, and a narrower bandwidth would result in more signal distortion, so this wide frequency band can be used to advantage. Also, the wide passband allows for temperature-induced shifts in the resonant frequency, i.e., scattering during manufacturing, to be tolerated without special measures, which is an advantage in terms of cost.

[0111] The thickness, particularly the average thickness, of the adhesive between the electroacoustic transducer and the barrier can be about 10 μm. The electroacoustic transducer can have a length of 205 μm in the direction of propagation of the acoustic wave.

[0112] Preferably, the adhesive thickness is distributed as uniformly as possible across the adhesive surface. However, the transmission channel is sufficiently stable that non-uniformity is acceptable. Rather, it indicates that there are areas where the piezoelectric disc directly contacts the acoustic medium.

[0113] Furthermore, the thinner the adhesive layer, the lower the acoustic loss.

[0114] It is therefore also possible, and advantageously possible, to attach the transducer directly to the material of the medium, for example by pressing it in.

[0115] Furthermore, it is possible and advantageous for the electroacoustic communication to use a frequency range around the NFC frequency 13.56 MHz, for example the frequency range 13.56 MHz±0.5 MHz.

[0116] Advantageously, the elements of the acoustic channel between the primary and secondary sides are adapted to the frequency range 13.56 MHz ± 0.5 MHz.

[0117] In particular, the elements of the acoustic channel can include an electro-acoustic transducer, an adhesive layer, and a medium.

[0118] The communication method may involve regular variation of the carrier frequency and / or amplitude, for example to compensate for changing environmental parameters such as temperature, expansion, pressure, or manufacturing tolerances. In particular, the primary side may inform the secondary side about different advantageous frequencies.

[0119] The variation in frequency can be based on received digital data that the primary side receives from the secondary side.

[0120] The secondary side first receives the command correctly from the primary side.

[0121] The secondary can then inform the primary of "good" and "bad" frequencies.

[0122] The division of "good" and "bad" frequencies can be based on bit error rate.

[0123] This has the advantage that no additional analog circuitry is required to separate "good" and "bad" frequencies, and in particular no evaluation of amplitude levels is required.

[0124] A corresponding acoustic transmission system can be used to introduce one or more measurements in a volume separated from the primary side by an airtight and / or impermeable barrier.

[0125] It is possible to measure temperature, gas pressure, humidity, etc.

[0126] In particular, the system can be used with high-voltage capacitors for galvanically isolated transmission to the outside.

[0127] It is also possible to use the error detection mechanisms of the transmission system to find the optimum carrier frequency, amplitude and modulation settings.

[0128] Here, the error detection mechanism or the corresponding error detection method can determine the error rate while varying one or, for example, several successive transmission parameters, and the parameter combination that results in an error rate below a predetermined threshold can be used as the parameter combination to be used in the actual operation of the system.

[0129] The secondary side can detect transmission errors in commands sent by the primary side and transmit this information back to the reader via the acoustic channel. The reader can then recognize the appropriate values, store them locally, for example in a table, and use them as settings if necessary.

[0130] Of course, it is also possible to detect and respond to errors in the secondary side's transmitted information.

[0131] It is important that the primary side has this information, as it is preferably able to control the flow of communication and specify the values ​​of the carrier frequency and other parameters.

[0132] This would also allow for continuous monitoring of the communication, for example to dynamically check whether other parameters become more favorable in the meantime.

[0133] It is possible to use four or more audio frequency bands in an audio transmission system to transmit the same information.

[0134] This improves interference resistance (for example, in cases of interference due to noise in metals or interference due to significant resonance in metals that statistically only tends to occur in certain frequency bands).

[0135] This is provided, for example, by the use of load modulation by the subcarriers.

[0136] It is also possible to use a two-stage modulation procedure when modulating the load.

[0137] In a first step, data can be modulated onto subcarriers, for example with Manchester coding, and then in a second step the subcarriers within the channel can be modulated onto a carrier frequency.

[0138] Furthermore, the primary side can always receive information from the secondary side simultaneously in four frequency bands in parallel, which are fixed relative to the carrier.

[0139] This makes it possible to transmit information simultaneously in four frequency bands.

[0140] The core aspects of the described apparatus of the primary side, secondary side and corresponding system, as well as details of the method of operation and preferred embodiment are explained in more detail in the schematic diagrams. [Brief explanation of the drawings]

[0141] [Figure 1] FIG. 1 shows an overview of the important elements of a transmission system. [Figure 2] FIG. 2 shows possible circuit elements on the primary and secondary sides. [Figure 3] FIG. 3 shows details of the acoustic channels. [Figure 4] FIG. 4 shows a spectrum with advantageous frequencies. [Figure 5] FIG. 5 shows the amplitude of a signal and its response over time. [Figure 6] FIG. 6 is a diagram showing an acoustic model of an acoustic signal. [Figure 7] FIG. 7 shows a possible transponder front-end circuit. [Figure 8] FIG. 8 is a diagram showing frequency ranges associated with time ranges. [Figure 9] FIG. 9 shows the possibility of contactless communication between the external circuit environment and the primary side. [Figure 10] FIG. 10 shows the possibility of contactless communication between the external circuit environment and the primary side. DETAILED DESCRIPTION OF THE INVENTION

[0142] 1 shows a barrier B separating the volume V of the secondary side S2 from the primary side S1. If the volume V of the secondary side S2 is separated gas-tight and the barrier B is impermeable to electromagnetic and possibly magnetic signals, the usual communication path between the primary and secondary sides will not work if a sensor for measuring a parameter is present on the secondary side and its signal is to be evaluated on the primary side S1.

[0143] However, it is possible to exchange information between the primary side S1 and the secondary side S2 using the material of the barrier B as a medium M for acoustic waves.

[0144] For this purpose, the transmission system comprises an electro-acoustic transducer EAW on the primary side S1 and a second electro-acoustic transducer EAW on the secondary side S2. Both electro-acoustic transducers EAW are directly connected to the medium M of the barrier B, for example by adhesive. Acoustic waves emitted from the electro-acoustic transducer EAW on the primary side S1 in the direction of the medium M can be received on the secondary side by the electro-acoustic transducer EAW on the secondary side. The possibility of electro-acoustic transducers converting between electric and acoustic signals therefore opens up the possibility of using electric signals on both sides of the barrier B and only acoustic signals for information transport across the barrier B. The transmission of acoustic signals also allows the simultaneous transmission of energy, so that the secondary side S2 can be supplied with energy from the primary side S1.

[0145] The primary side S1 contains a transmitter unit SE and a receiver unit EE. The secondary side contains a transponder TP. The transponder TP is used for communication with the primary side S1 and acts as an interface between the secondary side electro-acoustic transducer EAW and the secondary side logic circuit LC. The secondary side logic circuit LC can be used to drive and control the sensors and process the sensor signals.

[0146] FIG. 2 shows a possible configuration of a primary circuit combining elements of the transmitter unit SE and the receiver unit EE. The transmitter unit SE has a first signal line SL1 and a second signal line SL2. The first signal line SL1 connects the first transmitter terminal TX1 to an electrode of the electro-acoustic transducer. The second signal line SL2 connects the second transmitter terminal TX2 to a second electrode of the electro-acoustic transducer. The first and second transmitter terminals TX1 and TX2 represent two terminals of balanced guided transmit signal ports of the primary circuit. The first and second signal lines each comprise a series connection of an inductive element and a capacitive element. The inductive element is connected between the input connection and node A or B, respectively. The capacitive element is connected between node A or node B and the electrode of the electro-acoustic transducer. Furthermore, the inductive element is connected to the two electrodes of the electro-acoustic transducer.

[0147] Node B is connected to earth via a capacitive element. Node A is also connected to earth via a capacitive element. Node A is further connected to the unbalanced guide receiving terminal RX by a series connection of a resistive element and a capacitive element. A resistive element is connected between the supply connection SUP and the receiving connection RX. The supply connection is further connected to earth via a capacitive element.

[0148] On the secondary side, the electroacoustic transducer is connected to a transformer with two magnetically coupled inductive elements. The inductive element of the transformer that is not directly connected to the secondary electroacoustic transducer is connected to a parallel circuit consisting of an inductive element, a capacitive element, and an LC logic circuit.

[0149] The SE transmitter unit can receive input signals from the external circuit environment via two terminals TX1 and TX2. The signals are transmitted to the primary electroacoustic transducer via signal conductors SL1 and SL2. The corresponding acoustic waves reach the secondary electroacoustic transducer and are thereby converted into electrical signals on the secondary side. These are then converted into appropriate voltage and current values ​​by the secondary transformer and reach the logic circuit LC, allowing the primary side to control the secondary's activity. A possible response signal is sent back to the primary side S1 by the unit containing the secondary transducer and transponder TP and can be forwarded to the external circuit environment via the output port RX.

[0150] The primary circuit is suitable for supplying energy to the secondary circuit, for example by means of an essentially sinusoidal signal transmitted continuously at a carrier frequency, thereby eliminating the need to provide an additional energy storage device on the secondary side, which would otherwise have to be replaced periodically.

[0151] Figure 3 shows the components of an acoustic channel. Between the two electroacoustic transducers EAW, a barrier material B is placed, which acts as a medium for the propagation of acoustic waves between the transducers. Each transducer is connected to a medium M via an acoustic impedance matching element AIA. The acoustic impedance matching element AIA can be an adhesive with an appropriate acoustic impedance.

[0152] It is advantageous to use as thin an adhesive layer as possible or to have no adhesive layer at all.

[0153] Special impedance matching between the transducer and the medium is possible, but not necessary. Rather, reflections can be used to advantage in signal transmission, so a "too good" match is undesirable here.

[0154] Figure 4 shows the frequency spectrum of the response signal strength as a function of frequency, with the secondary transducer transmission conditions varied. VK represents the critical signal strength above which the received signal can be reliably evaluated. For the material combinations used, both 1:5 and 1:7 transformer transmission ratios and operating frequencies of 9.4 MHz, 10 MHz, and 10.9 MHz were found to be suitable.

[0155] Figure 5 shows possible amplitude curves for communication from the primary to the secondary side and the corresponding response from the secondary side. The primary side uses six wave packets and transmits them to the secondary side. After a certain waiting time (frame delay time), the secondary side responds with a specific signal that depends on the determined parameter values.

[0156] Figure 6 shows an analytical model of an acoustic signal that can be used to understand signal transmission. Each of the acoustically active elements between the transducer EAW (primary acoustic impedance matching element, barrier medium, secondary acoustic impedance matching element) can be represented by a complex impedance (Z) and admittance (Y) value. The effective reflection factor depends on the impedance jump at the interface between different materials, allowing for a simple selection of materials to enable high signal and energy transfer to the acoustic transducer.

[0157] Figure 7 shows a possible embodiment of a transducer (i.e., transponder) front-end circuit that can be used on the secondary side between the electroacoustic transducer and the secondary-side logic circuit. Transistors T1, T2, T3, T4, T5, and T6 form a rectifier. It has first and second inputs A1 and A2 that receive a sinusoidal AC signal with a carrier frequency of approximately 10 MHz, and an output SUP that supplies power in the form of DC voltage and current to the logic circuit.

[0158] Furthermore, this circuit has four circuit nodes A, B, C, and D. The capacitance between terminals A1 and A2 represents the unavoidable parasitic capacitance of MOS transistors and, if present, the parasitic capacitance of capacitive elements. Two transistors T3 and T4 are switches whose conduction or non-conduction is controlled by the voltage at their gate terminal (relative to the voltages at their source and drain terminals). Transistors T1 and T2 and transistors T6 and T7 are so-called MOS diodes (with their gate terminals connected to their drain terminals), i.e., their function is that of a diode. Overall, this configuration results in a rectifier that generates DC voltages at circuit nodes A and B, as well as A and D, whereby A represents the 0-volt reference or ground connection, and high voltages are formed at B and D compared to A.

[0159] To keep the DC voltage constant, a so-called voltage limiter is implemented. It consists of an operational amplifier and transistor T5. The operational amplifier compares the DC power supply voltage at point C, obtained from the voltage at point B via a voltage divider circuit consisting of resistors R1 and R2, with a constant voltage reference V_REF, such as a bandgap reference. This forms a control loop. When the AC input voltage between A1 and A2 increases, the output voltage of the operational amplifier changes so that the current conduction of transistor T5 becomes slightly higher, i.e., the source-drain impedance applied to points A and D becomes slightly smaller. This keeps the voltage at point B constant compared to the reference (GND) at point A. Therefore, a constant power supply voltage is essential to supply the subsequent logic circuit, which requires a time-varying current during operation.

[0160] However, changing the impedance of transistor T5 also affects the impedance applied between input terminals A1 and A2. Essentially, even if the input current of A1 changes, such as increasing, the voltage between A1 and A2 remains constant. This corresponds to a change in the input impedance between points A1 and A2 due to the regulation of transistor T5.

[0161] This concept can also be applied to generate load modulation. For this purpose, another transistor T8 can be used in parallel with T5, with its drain and source connected. The gate of T8 can then be modulated with a control voltage containing data to be transmitted at a subcarrier frequency in the form of a channel coding (e.g., Manchester coding). The subcarrier frequency can be, for example, a frequency generated by dividing the AC voltage at the carrier frequency between points A1 and A2 by, for example, a factor of 16 or 32. This subcarrier frequency can again be controlled by the data stream, for example, by Manchester coding.

[0162] Figure 8 shows the usable signals of the time period and frequency band obtained by the corresponding transformation. Specifically, the upper part of the figure shows the time axis curve, and the lower part shows the corresponding frequency components.

[0163] The top row of Figure 8 shows curves representing user data bits over a certain period of time, specifically 0s, 1s, and the transitions between them. The next row shows the progression of the associated channel coding. The third row shows the progression of the associated subcarriers over time. The fourth row shows the subcarriers modulated by the channel coding. The last row of the top row of Figure 8 shows the carriers subjected to load modulation.

[0164] The first row in the bottom of Figure 8 shows the channel coding in the frequency domain. The second row in the bottom of Figure 8 shows the modulated subcarriers in the frequency domain. The third row in the bottom of Figure 8 shows the load modulation on the carriers.

[0165] This means that via a suitably modulated subcarrier, the transmission frequency range can be doubled, or even quadrupled depending on the frequency spacing, which improves interference immunity (e.g., in the case of interference due to noise in metals or due to significant resonances in metals that statistically only occur in certain frequency bands).

[0166] Figure 9 shows an element of one form of transmission system in which a module with an air interface, in particular an NFC (Near Field Communication) interface, is provided on the primary side. This allows the primary side to be controlled contactlessly via a corresponding control device, for example a mobile communication terminal such as a mobile phone, and corresponding control software. For this purpose, the primary side module is equipped with a printed circuit board with corresponding electronic circuit components and an antenna. The antenna can be formed directly on the circuit board as a metallization or can be formed on the circuit board.

[0167] This primary contactless connection can be the only connection or in addition to connections via other connections such as cables. In systems with multiple main pages, the contactless connection can be used practically to assign each main page an ID number to its location within the system.

[0168] Figure 10 shows a variation in which the primary module is controlled via another module. The additional module can be connected to an external logic circuit, such as a computer bus system. The other module also contains a control element for contactless communication with the primary module.

[0169] Using the circuits and systems described above, communication barriers that are opaque to electromagnetic signals can be easily overcome using acoustic waves, with little circuit complexity or secondary energy requirements. [Explanation of symbols]

[0170] AIA: Acoustic Impedance Matching Element B: Barrier EAW: Electro-acoustic transducer RX: Receive connection EE: Receiving unit (Empfangseinheit) A1, A2: First connection, second connection V: Hermetically closed volume A, B, C, D: Circuit nodes VK: Critical output voltage LC: Logic circuit (Logikschaltung) M: Acoustic wave medium (Medium der akustischen Wellen) S1, S2: Primary side, secondary side (Primaerseite, Sekundaerseite) T1, ..., T8: first transistor... eighth transistor Transistor) TX1, TX2: Sending connection (Sendeanschluss) SE: Sending unit (Sendeeinheit) SL1, SL2: signal conductors TP: Transponder SUP: Power supply connection V_MOD: Modulation voltage V_REF: Constant voltage reference (Konstantspannungsreferenz)

[0171] [Appendix 1] 1. An audio transmission system, comprising: On the primary side, a transmitting unit designed and adapted to provide a transmitting signal; a receiving unit designed and adapted to receive a received signal in response to said transmitted signal; - an electro-acoustic transducer designed and adapted to convert the transmitted signal into an acoustic signal and the acoustic signal into a received signal, On the secondary side, a transponder designed and adapted to receive incoming signals and to transmit outgoing signals; an electroacoustic transducer; Between the primary side and the secondary side there is a medium that is transparent to acoustic signals. Sound transmission system. [Appendix 2] Further comprising a sensor on the secondary side. 2. The acoustic transmission system of claim 1. [Appendix 3] Further comprising a logic circuit on the secondary side. 3. The acoustic transmission system according to claim 1 or 2. [Appendix 4] A modulator or a MOSFET is provided on the secondary side. 4. An acoustic transmission system according to claim 1. [Appendix 5] Further provided on the secondary side is a modulator that modulates the electrical load of the electro-acoustic transducer on the secondary side. 5. An acoustic transmission system according to any one of claims 1 to 4. [Appendix 6] Further comprising a rectifier on the secondary side. 6. An acoustic transmission system according to any one of claims 1 to 5. [Appendix 7] The rectifier is - connected between the electroacoustic transducer and the modulator; and / or - directly connected to said modulator; 7. An acoustic transmission system according to any one of claims 4 to 6. [Appendix 8] a transistor whose base is connected to a connection for load modulation (V_MOD), 8. An acoustic transmission system according to any one of claims 1 to 7. [Appendix 9] The transistor is a MOSFET. 9. The acoustic transmission system of claim 8. [Appendix 10] a rectifier is provided between the electroacoustic transducer and the transistor; When the transistor is shorted for load modulation, the voltage across the electro-acoustic transducer becomes non-zero. 10. The acoustic transmission system according to claim 8 or 9. [Appendix 11] During modulation, the secondary clock can be derived from an incident acoustic wave having a carrier frequency to the primary. 11. An acoustic transmission system according to any one of claims 1 to 10. [Appendix 12] an intermediate energy storage unit on the secondary side; 12. An acoustic transmission system according to any one of claims 1 to 11. [Appendix 13] the transponder is designed and adapted to use the clock of the receiving unit as a system clock; 13. An acoustic transmission system according to any one of claims 1 to 12. [Appendix 14] There is no oscillator for return communication on the secondary side; 14. An acoustic transmission system according to any one of claims 1 to 13. [Appendix 15] There is no oscillator on the secondary side; 15. An acoustic transmission system according to any one of claims 1 to 14. [Appendix 16] further comprising an electrical impedance matching network on the secondary side; 16. An acoustic transmission system according to any one of claims 1 to 15. [Appendix 17] Further comprising a frequency reducer on the secondary side. 17. An acoustic transmission system according to any one of claims 1 to 16. [Appendix 18] The secondary side further includes a parallel circuit including an inductive element, a capacitive element, and a logic circuit, and a circuit unit having a converter. 18. An acoustic transmission system according to any one of claims 1 to 17. [Appendix 19] and further comprising a logic circuit front-end circuit on the secondary side, the logic circuit front-end circuit having a port, a power supply connection, four circuit nodes, an operational amplifier, and a transistor. 19. An acoustic transmission system according to any one of claims 1 to 18. [Appendix 20] Further comprising an acoustic impedance matching unit and / or an electrical impedance matching unit on the primary side and / or the secondary side, 20. An acoustic transmission system according to any one of claims 1 to 19. [Appendix 21] Further provided on the primary side is a frequency duplexer. 21. An acoustic transmission system according to any one of claims 1 to 20. [Appendix 22] the primary side is designed and adapted to supply energy to the secondary side; 22. An acoustic transmission system according to any one of claims 1 to 21. [Appendix 23] designed and adapted for one-way or two-way communication; 23. An acoustic transmission system according to any one of claims 1 to 22. [Appendix 24] The primary side further comprises an adaptation network having two signal conductors, a balanced guide input, an unbalanced guide output, a feed connection, three inductive elements and six capacitive elements. 24. An acoustic transmission system according to any one of claims 1 to 23. [Appendix 25] On the secondary side, means for recording and / or transmitting acoustic and / or optical perceptions are provided, 25. An acoustic transmission system according to any one of claims 1 to 24. [Appendix 26] The secondary side is provided with means for recording and / or transmitting audio, image, video, image and audio recordings, 26. An acoustic transmission system according to any one of claims 1 to 25. [Appendix 27] The secondary side element is operable by energy transmitted from the primary side. 27. An acoustic transmission system according to any one of claims 1 to 26. [Appendix 28] The information recorded on the secondary side can be transmitted as user data in the form of digital data. 28. An acoustic transmission system according to any one of claims 1 to 27. [Appendix 29] Video information recorded at the secondary side, either monochrome, grayscale or color images, can be transmitted to the primary side. 29. An acoustic transmission system according to any one of claims 1 to 28. [Appendix 30] The audio information recorded on the secondary side can be transmitted to the primary side as a mono or stereo signal. 30. An acoustic transmission system according to any one of claims 1 to 29. [Appendix 31] When transmitting an image or video, the start of a new image line can be transmitted externally. 31. An acoustic transmission system according to any one of claims 1 to 30. [Appendix 32] means for transmitting the start of a new image line to said secondary side; 32. An acoustic transmission system according to any one of claims 1 to 31. [Appendix 33] When transmitting a color image from the secondary side to the primary side, three values ​​can be transmitted for each image point. 33. An acoustic transmission system according to any one of claims 1 to 32. [Appendix 34] When transmitting a color image from the secondary side to the primary side, three values ​​can be transmitted for each image point. 34. An acoustic transmission system according to any one of claims 1 to 33. [Appendix 35] The primary side and the secondary side each have a circuit, and the size of the data frame is designed and adapted to transmit or receive the information to be transmitted. 35. An acoustic transmission system according to any one of claims 1 to 34. [Appendix 36] The data frame is 64 bytes in size. 36. The acoustic transmission system of claim 35. [Appendix 37] The primary side includes a module having an antenna or the primary side is expandable with a module having an antenna. 37. An acoustic transmission system according to any one of claims 1 to 36. [Appendix 38] designed and adapted to communicate with external communication equipment via an air interface; 38. The acoustic transmission system of claim 37. [Appendix 39] the external communication device is a mobile wireless terminal; 39. The acoustic transmission system of claim 38. [Appendix 40] The primary side and / or the secondary side can be controlled using an external communication device; 40. The acoustic transmission system of claim 39. [Appendix 41] The air interface is selected from the following: connection via a wireless transceiver, NFC connection, or Bluetooth connection. 41. An acoustic transmission system according to any one of claims 38 to 40. [Appendix 42] To the primary side - comprising a converter element, an energy storage and a circuit for converting data between different transmission standards, 42. An acoustic transmission system according to any one of claims 1 to 41. [Appendix 43] The energy storage unit is a battery or a rechargeable accumulator. 43. The acoustic transmission system of claim 42. [Appendix 44] A primary circuit included in the primary side of an acoustic transmission system according to any one of claims 1 to 43. [Appendix 45] A secondary circuit included in the secondary side of the acoustic transmission system according to any one of claims 1 to 20. [Appendix 46] 1. A method of transmitting using an acoustic transmission system, comprising: - transmitting a carrier signal using a primary transmitting unit to a secondary receiving unit; - receiving the carrier signal via the receiving unit; - generating a response signal based on the measurements; - transmitting the response signal to the primary side; A method comprising: [Appendix 47] the primary side and the secondary side are sealed and / or separated by a barrier that is impervious to electromagnetic signals; 47. The method of claim 46. [Appendix 48] Acoustic waves pass between the primary and secondary sides, transmitting information and / or energy. 48. The method of claim 46 or 47. [Appendix 49] the communication is point-to-point encrypted; 49. The method of any one of claims 46 to 48. [Appendix 50] said communication using encryption methods; 50. The method of claim 49. [Appendix 51] Encrypting data to prevent third parties from accessing and / or intentionally modifying its contents; 51. The method of claim 50. [Appendix 52] said communication being via digital signals; 52. The method of any one of claims 46 to 51. [Appendix 53] The communication may be unidirectional or bidirectional. 53. The method of any one of claims 46 to 52. [Appendix 54] The information is transmitted using a modulation selected from load modulation, amplitude modulation, phase modulation, frequency modulation, and complex modulation; 54. The method of any one of claims 46 to 53. [Appendix 55] The direction of data flow includes from the primary side to the secondary side. 55. The method of any one of claims 46 to 54. [Appendix 56] Modulations include individual modulations from sections 8 and 9 of standard ISO / IEC 14443-2_2010. 56. The method of any one of claims 46 to 55. [Appendix 57] using error detection or error correction methods; 57. The method of any one of claims 46 to 56. [Appendix 58] Data frames are sent from the primary side to the secondary side as needed and responded to by the secondary side. 58. The method of any one of claims 46 to 57. [Appendix 59] Between asynchronous data frames, only an unmodulated carrier frequency is transmitted from the primary side to the secondary side. 59. The method of any one of claims 46 to 58. [Appendix 60] Between the 8 bits of user data, a parity bit is transmitted according to standard ISO / IEC14443-3_2011. 60. The method of any one of claims 46 to 59. [Appendix 61] the transmission uses a cyclic redundancy check (CRC) mechanism; 61. The method of any one of claims 46 to 60. [Appendix 62] The cyclic redundancy check (CRC) is a CRC16 check or a CRC32 check according to the standard ISO / IEC 14443-3_2011, and the last 2x8 bits or 4x8 bits belong to the check, respectively; 62. The method of claim 61. [Appendix 63] Energy is stored intermediately on the secondary side. 63. The method of any one of claims 46 to 62. [Appendix 64] Longitudinal acoustic waves pass through a solid barrier, 64. The method of any one of claims 46 to 63. [Appendix 65] the communication is controlled by the primary side; 65. The method of any one of claims 46 to 64. [Appendix 66] One said primary side communicates with multiple said secondary sides; 66. The method of any one of claims 46 to 65. [Appendix 67] Use anti-collision methods; 67. The method of any one of claims 46 to 66. [Appendix 68] Uses communications having a frequency range of 1 MHz to 50 MHz; 68. The method of any one of claims 46 to 67. [Appendix 69] The electroacoustic communication uses a frequency in the frequency range of 13.56 MHz ± 0.5 MHz. 69. The method of claim 68. [Appendix 70] The elements of the acoustic channel between the primary side and the secondary side are adapted to a frequency range of 13.56 MHz ± 0.5 MHz; 70. The method of claim 69. [Appendix 71] The elements of the acoustic channel include an electro-acoustic transducer, an adhesive layer, and a medium; 71. The method of claim 70. [Appendix 72] further comprising varying the frequency and / or amplitude to compensate for changes in environmental parameters or manufacturing tolerances. 72. The method of any one of claims 46 to 71. [Appendix 73] varying the frequency based on received digital data received by the primary side from the secondary side; 73. The method of claim 72. [Appendix 74] The secondary side first correctly receives the command from the primary side; 74. The method of claim 73. [Appendix 75] The secondary side then informs the primary side of the "good" or "bad" frequency; 75. The method of claim 74. [Appendix 76] the classification of "good" and "bad" frequencies is based on bit error rate; 76. The method of claim 75. [Appendix 77] No additional analog circuitry is required for the classification into "good" and "bad" frequencies, and no evaluation of amplitude levels is required; 77. The method of claim 76. [Appendix 78] for querying measured values ​​in a volume that is gas-tight and / or electrically isolated from the primary side, 44. A method of using a system according to any one of claims 1 to 43. [Appendix 79] for measuring the temperature, gas pressure and / or humidity and / or pH value and / or pressure in a fluid medium, 79. The method of use of claim 78. [Appendix 80] To a high voltage capacitor for electrically isolated transmission to the outside, 80. The use of claim 78 or 79. [Appendix 81] A method of using an error detection mechanism in an acoustic transmission system to find a well-matched carrier frequency, amplitude, or modulation setting. [Appendix 82] A method of using an acoustic transmission system to use four or more acoustic frequency ranges in which the same information is transmitted. [Appendix 83] A two-stage modulation method is used for load modulation, 83. The method of use of claim 82. [Appendix 84] - Manchester coding data is modulated onto subcarriers in a first step, - the subcarriers are modulated in the channel again to a carrier frequency in a second step; 84. The method of use of claim 83. [Appendix 85] The primary side always receives information from the secondary side simultaneously in parallel in four frequency bands fixed to the carrier. 85. The method of use of claim 84. [Appendix 86] The information is always transmitted simultaneously in four frequency bands; 86. The method of use of claim 85.

Claims

1. 1. An audio transmission system, comprising: On the primary side, a transmitting unit designed and adapted to provide a transmitting signal; a receiving unit designed and adapted to receive a received signal in response to said transmitted signal; an electroacoustic transducer designed and adapted to convert said transmit signal into an acoustic signal and said acoustic signal into a receive signal; On the secondary side, a transponder designed and adapted to receive the received signal and to transmit the transmitted signal; an electroacoustic transducer, a medium between the primary side and the secondary side that is transparent to acoustic signals; the primary side includes a module having an antenna or the primary side is expandable with a module having an antenna; the primary side is configured to communicate with one or more of the secondary sides; Sound transmission system.

2. The acoustic transmission system of claim 1 , further comprising a sensor on the secondary side.

3. The acoustic transmission system according to claim 1 or 2, further comprising a logic circuit on the secondary side.

4. 4. The acoustic transmission system according to claim 1, further comprising a modulator or a MOSFET on the secondary side.

5. 5. The acoustic transmission system according to claim 1, further comprising a modulator on the secondary side for modulating an electrical load of the electro-acoustic transducer on the secondary side.

6. The acoustic transmission system according to claim 1 , further comprising a rectifier on the secondary side.

7. The rectifier is connected between the electroacoustic transducer and the modulator, and / or - directly connected to said modulator, 7. An acoustic transmission system according to any one of claims 4 to 6.

8. 8. An audio transmission system according to claim 1, comprising a transistor whose base is connected to a connection for load modulation (V_MOD).

9. 9. The audio transmission system of claim 8, wherein the transistor is a MOSFET.

10. a rectifier is provided between the electroacoustic transducer and the transistor; When the transistor is shorted for load modulation, the voltage across the electro-acoustic transducer becomes non-zero.

10. The acoustic transmission system according to claim 8 or 9.

11. 11. An acoustic transmission system according to any one of claims 1 to 10, wherein during modulation a clock on the secondary side can be derived on the primary side from an incident acoustic wave having a carrier frequency.

12. 12. An acoustic transmission system according to claim 1, comprising an intermediate energy store on the secondary side.

13. 13. An acoustic transmission system according to any one of claims 1 to 12, wherein the transponder is designed and adapted to use the clock of the receiving unit as a system clock.

14. 14. An acoustic transmission system according to claim 1, wherein the secondary side does not have an oscillator for return communication.

15. 15. An acoustic transmission system according to any one of claims 1 to 14, wherein the secondary side is oscillator-free.

16. 16. An acoustic transmission system according to any one of claims 1 to 15, further comprising an electrical impedance matching network on the secondary side.

17. 17. An acoustic transmission system according to any one of claims 1 to 16, further comprising a frequency reducer on the secondary side.

18. The acoustic transmission system according to claim 1 , further comprising, on the secondary side, a parallel circuit including an inductive element, a capacitive element, and a logic circuit, and a circuit unit having a converter.

19. 19. An audio transmission system according to any one of claims 1 to 18, further comprising a logic front-end circuit on the secondary side, the logic front-end circuit having a port, a power supply connection, four circuit nodes, an operational amplifier and a transistor.

20. 20. The acoustic transmission system according to claim 1, further comprising an acoustic impedance adaptor and / or an electrical impedance adaptor on the primary side and / or the secondary side.

21. 21. The acoustic transmission system according to claim 1, further comprising a frequency splitter on the primary side.

22. 22. An acoustic transmission system according to any one of claims 1 to 21, wherein the primary side is designed and adapted to supply energy to the secondary side.

23. 23. An acoustic transmission system according to any one of claims 1 to 22, designed and adapted for one-way or two-way communication.

24. 24. An acoustic transmission system according to any one of claims 1 to 23, further comprising, on the primary side, an adaptation network having two signal conductors, a balanced guide input, an unbalanced guide output, a feed connection, three inductive elements and six capacitive elements.

25. 25. An acoustic transmission system according to any one of the preceding claims, comprising, on the secondary side, means for recording and / or transmitting acoustic and / or optical perceptions.

26. 26. An audio transmission system according to any one of claims 1 to 25, comprising means on the secondary side for recording and / or transmitting audio recordings, image recordings, video recordings, image and audio recordings.

27. 27. An acoustic transmission system according to any one of claims 1 to 26, wherein the secondary elements are operable by energy transmitted from the primary.

28. 28. An audio transmission system according to any one of claims 1 to 27, wherein the information recorded at the secondary side is transmittable as user data in the form of digital data.

29. 29. An audio transmission system according to any one of the preceding claims, wherein video information recorded at the secondary side, of monochrome, greyscale or colour images, can be transmitted to the primary side.

30. 30. An audio transmission system according to any one of claims 1 to 29, wherein audio information recorded at the secondary side can be transmitted to the primary side as a mono or stereo signal.

31. 31. An audio transmission system according to any one of claims 1 to 30, wherein when transmitting an image or video, the start of a new image line can be transmitted to the outside.

32. 32. An acoustic transmission system according to any preceding claim, comprising means for transmitting the start of a new image line to the secondary side.

33. 33. An acoustic transmission system according to any one of the preceding claims, wherein when transmitting a colour image from the secondary side to the primary side, three values ​​can be transmitted for each image point.

34. 33. An acoustic transmission system according to any one of the preceding claims, wherein when transmitting a colour image from the secondary side to the primary side, three values ​​can be transmitted for each image point.

35. 35. An acoustic transmission system according to any one of claims 1 to 34, comprising circuits on the primary side and the secondary side, respectively, the size of a data frame being designed and adapted to transmit or receive information to be transmitted.

36. 36. An audio transmission system according to claim 35, wherein said data frames are 64 bytes in size.

37. 37. An acoustic transmission system according to any one of claims 1 to 36, designed and adapted to communicate with external communication equipment via an air interface.

38. 38. An acoustic transmission system according to claim 37, wherein the external communication device is a mobile radio terminal.

39. 39. An acoustic transmission system according to claim 38, wherein the primary side and / or the secondary side can be controlled using an external communication device.

40. 40. The audio transmission system according to any one of claims 37 to 39, wherein the air interface is selected from the group consisting of a connection via a transceiver of a wireless standard, an NFC connection, and a Bluetooth connection.

41. To the primary side An acoustic transmission system according to any one of claims 1 to 40, comprising a converter element, an energy store and a circuit for converting data between different transmission standards.

42. 42. The acoustic transmission system of claim 41, wherein the energy storage unit is a battery or a rechargeable accumulator.

43. A primary circuit including a primary element of an acoustic transmission system according to any one of claims 1 to 42.

44. A secondary circuit including a secondary element of an acoustic transmission system according to any one of claims 1 to 20.

45. 1. A method of transmitting using an acoustic transmission system, comprising: - transmitting a carrier signal using a primary transmitting unit to a secondary receiving unit; receiving said carrier signal via said receiving unit; generating a response signal based on the measurements; transmitting said response signal to said primary side, The acoustic transmission system includes: On the primary side, a transmitting unit designed and adapted to provide a transmitting signal; a receiving unit designed and adapted to receive a received signal in response to said transmitted signal; an electroacoustic transducer designed and adapted to convert said transmit signal into an acoustic signal and said acoustic signal into a receive signal; On the secondary side, a transponder designed and adapted to receive the received signal and to transmit the transmitted signal; an electroacoustic transducer, a medium between the primary side and the secondary side that is transparent to acoustic signals; the primary side includes a module having an antenna or the primary side is expandable with a module having an antenna; the primary side is configured to communicate with one or more of the secondary sides; method.

46. 46. ​​The method of claim 45, wherein the primary side and the secondary side are sealed and / or separated by a barrier that is impervious to electromagnetic signals.

47. 47. A method according to claim 45 or 46, wherein acoustic waves pass through a barrier between the primary side and the secondary side to transmit information and / or energy.

48. 48. A method according to any one of claims 45 to 47, wherein the communication is point-to-point encrypted.

49. 49. The method of claim 48, wherein the communication uses encryption methods.

50. 50. The method of claim 49, further comprising encrypting the data to prevent third parties from accessing and / or intentionally modifying the content.

51. 51. A method according to any one of claims 45 to 50, wherein said communication is via digital signals.

52. 52. A method according to any one of claims 45 to 51, wherein the communication is unidirectional or bidirectional.

53. 53. A method according to any one of claims 45 to 52, wherein the information is transmitted using a modulation selected from load modulation, amplitude modulation, phase modulation, frequency modulation and complex modulation.

54. 54. The method of any one of claims 45 to 53, wherein the direction of data flow includes from the primary side to the secondary side.

55. 55. A method according to any one of claims 45 to 54, wherein the modulations include individual modulations from sections 8 and 9 of standard ISO / IEC 14443-2_2010.

56. 56. A method according to any one of claims 45 to 55, using an error detection or error correction method.

57. 57. A method according to any one of claims 45 to 56, wherein data frames are sent from the primary side to the secondary side and responded to by the secondary side as required.

58. 58. A method according to any one of claims 45 to 57, wherein between asynchronous data frames only an unmodulated carrier frequency is transmitted from the primary side to the secondary side.

59. 59. A method according to any one of claims 45 to 58, wherein a parity bit is transmitted between the 8 bits of user data in accordance with standard ISO / IEC 14443-3_2011.

60. 60. A method according to any one of claims 45 to 59, wherein said transmission uses a cyclic redundancy check (CRC) mechanism.

61. 61. The method of claim 60, wherein the cyclic redundancy check (CRC) is a CRC16 or CRC32 check according to standard ISO / IEC 14443-3_2011, the last 2x8 bits or 4x8 bits respectively belonging to the check.

62. 62. The method of any one of claims 45 to 61, wherein energy is intermediately stored on the secondary side.

63. 63. The method of any one of claims 45 to 62, wherein the longitudinal acoustic wave passes through a solid barrier.

64. 64. The method of any one of claims 45 to 63, wherein the communication is controlled by the primary side.

65. 65. A method according to any one of claims 45 to 64, using an anti-collision method.

66. 66. The method of claim 65, using communications having a frequency range of 1 MHz to 50 MHz.

67. 67. The method of claim 66, wherein the electroacoustic communication uses frequencies in the frequency range of 13.56 MHz ±0.5 MHz.

68. 68. The method of claim 67, wherein elements of an acoustic channel between the primary side and the secondary side are adapted to a frequency range of 13.56 MHz ± 0.5 MHz.

69. 69. The method of claim 68, wherein the elements of the acoustic channel include an electro-acoustic transducer, an adhesive layer, and a medium.

70. 70. A method according to any one of claims 45 to 69, further comprising varying the frequency and / or amplitude to compensate for changes in environmental parameters or manufacturing tolerances.

71. 71. The method of claim 70, wherein varying the frequency is based on received digital data received by the primary side from the secondary side.

72. 72. The method of claim 71, wherein the secondary side first correctly receives the primary side's command.

73. 73. The method of claim 72, wherein the secondary side then notifies the primary side of a "good" or "bad" frequency.

74. 74. The method of claim 73, wherein the classification of frequencies into "good" and "bad" frequencies is based on bit error rate.

75. 75. The method of claim 74, wherein the classification into "good" and "bad" frequencies does not require additional analog circuitry and does not require evaluation of amplitude levels.

76. 43. A method of using a system according to any one of claims 1 to 42 for interrogating measurements in a volume that is gas-tight and / or electrically isolated from the primary side, comprising: The acoustic transmission system includes: On the primary side, a transmitting unit designed and adapted to provide a transmitting signal; a receiving unit designed and adapted to receive a received signal in response to said transmitted signal; an electroacoustic transducer designed and adapted to convert said transmit signal into an acoustic signal and said acoustic signal into a receive signal; On the secondary side, a transponder designed and adapted to receive the received signal and to transmit the transmitted signal; an electroacoustic transducer, a medium between the primary side and the secondary side that is transparent to acoustic signals; the primary side includes a module having an antenna or the primary side is expandable with a module having an antenna; the primary side is configured to communicate with one or more of the secondary sides; method.

77. 77. A method according to claim 76 for measuring the temperature, gas pressure and / or humidity and / or pH value and / or pressure in a fluid medium.

78. 78. A method according to claim 76 or 77, comprising using the system in a high voltage capacitor for electrically isolated transmission to the outside.

79. 1. A method of using an error detection mechanism in an acoustic transmission system to find a well-matched carrier frequency, amplitude, or modulation setting, comprising: The acoustic transmission system includes: On the primary side, a transmitting unit designed and adapted to provide a transmitting signal; a receiving unit designed and adapted to receive a received signal in response to said transmitted signal; an electroacoustic transducer designed and adapted to convert said transmit signal into an acoustic signal and said acoustic signal into a receive signal; On the secondary side, a transponder designed and adapted to receive the received signal and to transmit the transmitted signal; an electroacoustic transducer, a medium between the primary side and the secondary side that is transparent to acoustic signals; the primary side includes a module having an antenna or the primary side is expandable with a module having an antenna; the primary side is configured to communicate with one or more of the secondary sides; method.

80. 1. A method for using an acoustic transmission system to use four or more acoustic frequency ranges in which identical information is transmitted, comprising: The acoustic transmission system includes: On the primary side, a transmitting unit designed and adapted to provide a transmitting signal; a receiving unit designed and adapted to receive a received signal in response to said transmitted signal; an electroacoustic transducer designed and adapted to convert said transmit signal into an acoustic signal and said acoustic signal into a receive signal; On the secondary side, a transponder designed and adapted to receive the received signal and to transmit the transmitted signal; an electroacoustic transducer, a medium between the primary side and the secondary side that is transparent to acoustic signals; the primary side includes a module having an antenna or the primary side is expandable with a module having an antenna; the primary side is configured to communicate with one or more of the secondary sides; method.

81. 81. The method of claim 80, wherein a two-stage modulation method is used for load modulation.

82. - Manchester coded data are modulated onto subcarriers in a first step, 82. A method according to claim 81, wherein the subcarriers are modulated in the channel again to a carrier frequency in a second step.

83. 83. The method of claim 82, wherein the primary side always receives the secondary side information simultaneously in parallel on four frequency bands fixed relative to a carrier.

84. 84. The method of claim 83, wherein said information is transmitted simultaneously on four frequency bands at any one time.

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