Small hardware and method for transmitting and receiving signals without interference.

Abstract

A system and method for an ultrasonic apparatus are presented. The system may include an ultrasonic transducer having terminals, a driver electrically connected to the ultrasonic transducer via the terminals, and a receiver electrically connected to the ultrasonic transducer via the terminals. The ultrasonic transducer is configured to simultaneously transmit and receive modulated signals, and a method that takes this simultaneous transmission and reception into consideration is used.

Description

[Technical Field]

[0001] This invention relates to the field of ultrasonic signal transmission and reception. More specifically, it relates to apparatus and methods for pulse-echo and pitch-catch (transmission) measurements of ultrasonic signals. Ultrasonic measurements can be used in medical diagnostic methods, such as scanning and measuring structures inside the human or animal body. Ultrasonic measurements can also be used in non-destructive evaluation processes, such as finding defects in materials and structures, or determining the properties of subsurface structures and materials. These methods and apparatus can be applied to radio frequency signals (RF signals), which are any signals in the frequency range from about 20 kHz to about 300 GHz. [Background technology]

[0002] In non-destructive ultrasonic evaluation, the recorded signal is weaker than the transmitted signal due to phenomena such as beam diffusion, attenuation, and incomplete reflection and scattering. To overcome this and enable digitization of the signal with a sufficient signal-to-noise ratio (SNR) and dynamic range, conventional systems avoid overloading and saturating the receiving amplifier by using a short-duration high-voltage pulser and a transmit / receive switch that disconnects the transmitter from the receiver. The use of a high-voltage transmitted signal increases the amplitude of the received pulse, thus improving the SNR against random noise. Because the transmitted and received events are separated, conventional acquisition systems cannot transmit and receive signals simultaneously. That is, a short, sharp, high-amplitude signal is sent to the transducer or radiating element, and after transmission, the transducer is connected to an amplifier to amplify the weaker received signal before digitizing and recording it. Short pulses are used so that the receiving stage can start quickly, reducing the dead zone of the received signal and minimizing the time width of the received signal, which is important for improving the range resolution of the measurement. When short pulses are emitted in a multi-element transducer, it is impossible for the receiver to identify which transducer emitted a particular pulse. Therefore, for comprehensive data acquisition, it is necessary to fire each transducer sequentially and collect a complete set of data from all transducers that have transmitted and received signals (full matrix capture).

[0003] Because it separates transmitted and received events, the hardware design for pulsed RF transceivers is specialized. In particular, ultrasound generates high-voltage spikes, and specific electronic circuit hardware is required to isolate these spikes from the receiving amplifier, amplify the received signal, and digitize the received signal. This hardware is space-consuming, energy-intensive, and expensive, and in some applications, such as small inspection robots or permanent sensors, energy supply is limited and available space is restricted. [Overview of the project]

[0004] The present invention relates to an ultrasonic apparatus and a method for operating an ultrasonic apparatus, as substantially described herein. The invention is defined by the claims, as can be understood in light of the following description and drawings. [Brief explanation of the drawing]

[0005] [Figure 1] This is a schematic diagram of a conventional RF / ultrasonic pulse echo system including a switching circuit. [Figure 2] This is a schematic diagram of an RF / ultrasonic pulse echo system according to an embodiment of the present invention. [Figure 3A] This figure shows a conventional non-periodic series and the corresponding autocorrelation results. [Figure 3B] This figure shows a conventional random long sequence and its corresponding autocorrelation result. [Figure 4] This figure shows an exemplary long series according to the embodiment, the autocorrelation of the series, and the corresponding correlation results for an appropriate modified template that generates correlation peaks and exclusion zones. [Figure 5] This figure shows the correlation results of an exemplary long series for a fixed, appropriate template, in the case where this exemplary long series is circularly shifted. [Figure 6A] This figure shows the first and second members from a circularly shifted long-sequence family, as well as the corresponding correlation results within the exclusion zone, where all family members are filtered against their respective templates from the first and second sequences. [Figure 6B] Figure 6A shows the third and fourth members of the circularly shifted long series family, and the corresponding correlation results within the exclusion zone, where all family members are filtered against the respective templates from the third and fourth series. [Modes for carrying out the invention]

[0006] With respect to Figure 1, a schematic diagram of a conventional ultrasonic system 100 is shown. The conventional ultrasonic system 100 may include a controller 102 that controls the system 100. The controller 102 may also provide some analysis of the signals obtained from the rest of the system 100, or provide communication to another computer or processor that analyzes these signals. The controller 102 controls a driver 104 that supplies power to drive a transducer 110, causing ultrasonic energy 120 to be released into a medium 112. The power supplied to the transducer 110 by the driver 104 may be high voltage to ensure a clear return response with a good signal-to-noise ratio. Once the ultrasonic energy 120 is released into the medium 112, the structure and physical properties of the medium 112 may determine the reflected or returned response 122. For example, changes in density or wave velocity within the medium may cause reflection of the ultrasonic energy 120 or a portion thereof, resulting in a return response 122. The transducer 110 is capable of converting electrical energy into an ultrasonic signal, but it is also capable of converting the return ultrasonic response 122 into electrical energy. The electrical signal generated by the transducer 110 in accordance with the returned response 122 is passed to the receiver 108. The receiver 108 includes an analog-to-digital (A / D) converter 114, which supplies a digital signal corresponding to the electrical signal supplied from the transducer 110 to the receiver 108. The digital signal is then returned to the controller 102 so that the returned response 122 can be processed for analysis of the medium 112. Importantly, in the conventional ultrasonic system 100 shown in Figure 1, the driver 104 and the receiver 108 communicate with the transducer 110 via one or more switching circuits 106. In the conventional system 100, the switching circuits 106 are important.This is because it is desirable to drive the transducer 110 with a large amount of power to maximize the ultrasonic energy 120 emitted into the medium 112, and also desirable that the receiver 108 be able to record the returned response 122 with sufficiently high accuracy over a reduced voltage range, and so that the signal is noticeably detectable above the noise limit determined by the dynamic range of the A / D converter 114.

[0007] Conventional systems 100 require isolation between the drive circuit and the measurement circuit by a switching circuit 106 or a nonlinear isolation circuit in order to function correctly and detect the signal, thus adding cost, complexity, and size to conventional systems 100. However, these additions can be mitigated if these switching circuits 106 can be simplified or completely eliminated. Switching circuits 106 or nonlinear isolation circuits in radio frequency measurements are costly and complex due to the requirement that high voltages must be switched or isolated as quickly as possible. In addition, the very existence of switching circuits 106 means that it is not possible to simultaneously emit ultrasonic energy 120 and measure the returned response 122 using a single transducer 110. Rather, at any given time, transducer 110 can be used either to emit energy 120 or to measure the response 122. In reality, the switching circuit 106 is not perfect, so some of the emitted energy 120 is distorted or spills into the response 122, resulting in a slight dead time, i.e., a period during which the received signal is weakened by leakage from the emitted energy and is usually discarded.

[0008] With reference to Figure 2, an exemplary ultrasonic system 200 according to an embodiment of the present invention is described. Figure 2 shows a schematic diagram of the ultrasonic system 200 according to an embodiment. The ultrasonic system 200 may include a controller 202 that controls the system 200. The controller 202 may also provide some analysis of signals obtained from the remainder of the system 200, or provide communication to another computer or processor (not shown) that analyzes these signals. The controller 202 controls a driver 204 that supplies power to drive a transducer 210, causing ultrasonic energy 220 to be released into a medium 212. The power supplied to the transducer 210 by the driver 204 may be at a relatively low voltage compared to conventional ultrasonic systems, or alternatively, the power supplied to the transducer 210 by the driver 204 may be at a conventional voltage or a high voltage. Once the ultrasonic energy 220 is released into the medium 212, the structure and physical properties of the medium 212 may determine the reflected or returned response 222. For example, changes in density or wave velocity within the medium can cause reflection of ultrasonic energy 220 or a portion thereof, resulting in a return response 222. The transducer 210 can convert electrical energy into an ultrasonic signal, but it can also convert the return ultrasonic response 222 into electrical energy. The electrical signal generated by the transducer 210 in response to the returned response 222 is passed to the receiver 208. The receiver 208 includes an A / D converter 114, which supplies a digital signal corresponding to the electrical signal supplied from the transducer 210 to the receiver 208. The digital signal is then returned to the controller 202 so that the returned response 222 can be processed for analysis of the medium 212.

[0009] The ultrasonic driver 204 and receiver 208 communicate directly with the transducer 210 simultaneously. That is, the receiver 208 continuously records the signal at the transducer 210 terminals without switching or interruption. The receiver 208 is configured to simultaneously measure the drive signal from the driver 204 and the converted return response 222 from the medium. The A / D converter 214 of the receiver 208 is configured to have a range that can record the voltage at the transducer 210 terminals. The range of the A / D converter 214 may be selected to exceed the maximum voltage range that can be applied by the driver 204. The range of the driver 204 may be limited by the physical properties of the driver 204 (i.e., the driver 204 may not be physically able to supply a larger drive signal), or it may be limited by software or upper limit constraints (capping) on ​​the maximum drive signal supplied. Since the maximum range of the A / D converter 214 exceeds the drive voltage of the driver 204, the A / D converter can provide a complete measurement of the drive signal without cutoff. Since the returned response 222 signal is always lower than the drive signal supplied by the driver 204, such a range also ensures that the complete return response 222 can be measured reliably without any truncation.

[0010] Since the embodiment shown in Figure 2 does not include a switching circuit, the size, energy requirements, complexity, and cost of the system 200 can be significantly reduced. However, steps may be taken to minimize the potential impact such changes may have on the recovery of the signal-to-noise ratio of the transducer 210's measurement response.

[0011] One step that can be taken to improve the signal-to-noise ratio recovery is to increase the total transmitted energy of the ultrasonic energy 220 emitted into the medium 212. The total transmitted energy can be increased by transmitting a time-long encoded signal based on a predefined sequence that contains relatively more energy as the voltage decreases. This is useful because the signal-to-noise ratio may be proportional to the total transmitted energy. The encoded signal received by transducer 210 can be matched and / or pulse-compressed to capture a short time-domain signal with a relatively high signal-to-noise ratio. Receiver 208 can also decouple the drive signal from driver 204, since the drive signal is known from controller 202, which controls driver 204.

[0012] In the field of ultrasonic measurement, it is widely accepted that sequences with desirable aperiodic correlation characteristics are most suitable for pulsed echo applications. Periodic sequences are expected to be useful only in transmission or other continuous wave applications. This is because periodic sequences with desirable characteristics only exist as lengths that require excitation times exceeding the duration for which useful information is expected to arrive in pulsed echo applications, which means that conventional hardware architecture 100 is unsuitable because it requires simultaneous transmission and reception. While the use of periodic sequences in aperiodic form may be applicable to pulsed echo applications, it cannot be applied in combination with conventional hardware architecture 100. This is because the limitations on excitation time imposed by hardware architecture 100 significantly shorten the length of sequences that can be used. Using short excitation times with periodic sequences results in a filtered signal containing significant filter artifacts, complicating or making further analysis impossible.

[0013] Figure 3A shows a conventional nonperiodic sequence that can be encoded in ultrasonic signals emitted from an ultrasonic system. The sequence shown in Figure 3A is a binary Barker sequence of length 13, taking the values ​​[1,1,1,1,1,-1,-1,1,1,-1,1,-1,1]. The first chart in Figure 3A shows the Barker sequence. The second chart in Figure 3A shows the ideal autocorrelation result for the Barker sequence. The autocorrelation function of the Barker sequence shows a strong autocorrelation peak at zero time delay surrounded by low levels of self-noise (indicating strong reliability of the signal correlation). Self-noise is essentially an indicator that there is some degree of correlation between the signal and the signal itself when time-shifted, which can lead to misidentification from the presence of other signals. The Barker sequence is often described as having one of the best autocorrelation characteristics due to its strong autocorrelation peak and surrounding low levels of self-noise.

[0014] Figure 3B shows another conventional non-periodic random sequence of length 500. Random sequences of sufficiently long length produce a good autocorrelation response because, as the sequence length increases, the opportunity for correlation noise from separate segments with the sequence decreases. The first chart in Figure 3B shows an exemplary random sequence in a binary [1,-1] signal, and the second chart in Figure 3B shows the autocorrelation of this sequence. As can be seen, sufficiently long random sequences produce a strong autocorrelation peak surrounded by self-noise resulting from a certain degree of similarity with time-delayed random sequences.

[0015] Figure 4 shows an exemplary long sequence according to an embodiment of the present invention. The first chart in Figure 4 shows a ternary [1,0,-1] coded sequence with a length of 503 elements. At first glance, this sequence resembles a random sequence, but differs in several key respects. The sequence shown in Figure 4 is configured to have a perfectly correlated response within a specific region when correlated with a signal consisting of a number of concatenated copies (N=3 in the example in Figure 4) of the original coded sequence known as the template. That is, the correlation result includes a major peak when the center of the template aligns with the original coded sequence. The correlation result is zero for any element number up to the sequence length (e.g., 503 in Figure 4) in both directions of the major peak. The zero response is known as the exclusion region. The use of a sequence with a correlated output that includes an exclusion region surrounding the correlated peak, as exemplified by the sequence shown in Figure 4, means that the returned response is not surrounded by filter artifacts that could confuse the analysis of the response. In addition, reflections from nearby reflectors to the medium do not result in the superposition of filter artifacts, which can significantly increase the amplitude of the artifact. Furthermore, the sequence is longer (compared to, for example, the Barker sequence), meaning it has higher total energy. Consequently, the correlation of the returned response 222 can enable a low voltage or low power signal applied to the medium 212 over a period of time to generate an ultrasonic response with an excellent signal-to-noise ratio.

[0016] Another advantage of the nearly perfect correlation response of the series illustrated in Figure 4 is that the dynamic range of the ultrasonic system 200 can be improved. The system's dynamic range is determined by the level of noise on both sides of the correlation peak compared to the peak itself. Since the difference between the correlation peak and the exclusion zone is as large as possible, the system's dynamic range is theoretically infinite or perfect and is limited only by imperfections in the hardware implementation.

[0017] [Explanation of hardware implementation] In an embodiment of the invention, an ultrasonic device 200 is provided that includes an ultrasonic transducer 210 having a terminal 216. The ultrasonic device includes a driver 204 that is electrically communicative with the ultrasonic transducer 210 via the terminal 216, and a receiver 208 that is electrically communicative with the ultrasonic transducer 210 via the terminal 216. Since both the driver 204 and the receiver 208 are always electrically communicative with the transducer 210 via the terminal 216, the receiver 208 is also electrically communicative with the driver 204 via the terminal 216. The ultrasonic transducer 210 is configured to simultaneously transmit and receive modulation signals 220, 222. Although the transducer 210 is shown as having a single terminal 216 for clarity, the transducer 210 may have one or several connectors that form a complete electrical circuit, and the terminal 216 may include one or all of these connectors.

[0018] The receiver 208 is configured to continuously measure the terminal 216 of the ultrasonic transducer 210 over the duration of the transmitted signal 220. For example, the receiver 208 can continuously record the voltage level at the terminal 216 while the signal 220 is being transmitted continuously by the transducer 210 and also when the return signal 222 is being received. In this way, the receiver 208 can record the entire return signal 222 without interruption. In contrast, conventional systems may require the receiver to interrupt recording the return signal in order to allow the transmission signal to be emitted.

[0019] The receiver 208 may be configured to continuously measure the terminal 216 of the ultrasonic transducer 210 over an additional measurement period to construct the received signal. That is, the receiver 208 can continuously measure the return signal 222 and the output of the driver 204 at the terminal 216 of the transducer 210 over a period of time after the entire signal has been transmitted. The additional period may be up to 1000 times the length of the transmitted signal 220.

[0020] The transmitted modulated signal 220 may be modulated according to a predetermined sequence. In order to modulate the transmitted modulated signal 220 according to a predetermined sequence, the modulated characteristic of the transmitted modulated signal 220 may be the phase, frequency, or amplitude of the signal, or a mixture of these characteristics. The predetermined sequence may be a binary sequence taking values ​​of 1 and -1 (or 1 and 0, on and off, high and low, etc.), or a ternary sequence taking values ​​of 0, 1, or -1.

[0021] The modulated component of the transmitted signal 220 may be a default symbol or waveform. As such, the default symbol can be matched in frequency content to the frequency response of an ultrasonic transducer. By matching the frequency content of the default symbol to the frequency response of the ultrasonic transducer 210, the default sequence can be effectively used for a particular ultrasonic transducer and tuned to that ultrasonic transducer 210. In this way, the phase, frequency, or amplitude of repeated copies of the default symbol can be modulated using the default sequence. The length of the default symbol is configurable by the user at their discretion. By configuring the length of the default symbol, the bandwidth of the transmitted modulated signal 220 can be adjusted.

[0022] The transmitted modulated signal 220 is applied to the transducer terminal 216 the first time. In this way, the default sequence can be used aperiodically. That is, the transmitted modulated signal 220 may be emitted once from the transducer 210 and the return signal 222 may be measured once. A further transmitted signal 220 may be emitted at some point after the first time, provided that the transmitted modulated signal 220 is not periodic (i.e., not repeated at regular time intervals).

[0023] The ultrasonic device 200 further includes a processor 202 in communication with a receiver 208. The processor is configured to filter the received signal 222 using a matched filter to generate an output signal. The matched filter is constructed from a corresponding template signal. The corresponding template signal can be generated to correspond to the transmitted modulated signal 220, so that the filtered output signal provides information about the medium 212 through which the receiver signal 222 has passed.

[0024] A template signal can be generated by concatenating N copies of the transmitted modulated signal. That is, the template signal can consist of multiple concatenated copies of the transmitted modulated signal, where N may be any integer greater than 1. Optionally, the copies may be alternately multiplied by -1 during the concatenation of the N copies. The template signal can also be derived from a default sequence, i.e., by concatenating N copies of a signal consisting of modulation by a default sequence of symbols different from the default symbols used to generate the transmitted modulated signal.

[0025] In an alternative embodiment, the default sequence is constructed from two complementary Golay sequences. For example, two complementary sequences may be selected such that, when combined, they have perfect correlation characteristics. That is, these complementary sequences contain self-noise in their respective autocorrelations, which are similar in position but opposite in polarity, and therefore, by adding the two autocorrelations, the amplitude of the correlation peak is doubled while allowing for complete cancellation of the self-noise. Each of the complementary Golay sequences may be separated by a fixed offset amount. The fixed offset amount may be fixed such that the offset between the complementary sequences is known. Between the complementary sequences, the value of the default sequence is zero, i.e., a zero signal exists in the offset between the complementary sequences. The time difference (DTG) between the start of the first Golay sequence of the two complementary Golay sequences and the start of the second Golay sequence of the two complementary Golay sequences may be definable by the user.

[0026] To generate an output signal from the return signal 222, the result of the matched filter may be shifted by DTG to generate the shifted matched filter result. By adding the matched filter result to the shifted matched filter result, the output signal is generated. For example, if a pair of Goley sequences are received and separated by DTG in the matched filter results, the sum of the matched filter result and the shifted matched filter result will show a strong correlation without self-noise.

[0027] In an alternative embodiment, the default sequence has a correlation function for its N concatenated copies such that the length L of the default sequence is on both sides. seq The system is configured to have a principal correlation peak surrounded by an exclusion region, and this correlation peak itself is surrounded by a region containing additional correlation peaks and self-noise. That is, a default sequence can be constructed or selected that has ideal or perfect correlation characteristics within a particular window when correlated to a suitable template. The exclusion region of the correlation function output is L on both sides of the central correlation peak. seq The shift is zero, and here L seq is the length of the default sequence. N consecutive copies of the correlation function can be multiplied alternately by -1; that is, every other consecutive copy of the default sequence can be reversed.

[0028] To generate the output signal, the processor 202 can select a region in the filtered output that starts at J times the length of the transmitted modulated signal 220 and ends at J+1 times the length of the transmitted modulated signal. For example, in the filtered output, a region between twice the length of the transmitted modulated signal 220 and three times the length of the transmitted modulated signal 220 may be selected. N is a positive integer greater than 1. J may be less than N, so that the selected region lies within the range of the received modulated signal 222 corresponding to the transmitted modulated signal 220.

[0029] The ultrasonic device 202 described in this book may be implemented across multiple ultrasonic transducers 210. Each of the multiple ultrasonic transducers 210 may be configured to simultaneously transmit and receive modulated signals and operate simultaneously. The signal modulation described in this book enables simultaneous transmission and reception across multiple ultrasonic transducers 210 while allowing for the isolation of individual signals corresponding to each of the multiple transducers 210.

[0030] Each of the multiple ultrasonic transducers 210 can be configured to transmit a different modulation signal, and each different modulation signal contains a different default sequence within a family of multiple default sequences. The family of default sequences can be selected as described below.

[0031] In each different default sequence within a family of default sequences, the correlation function for its own N consecutive copies has a correlation peak and a correlation exclusion region. That is, each point in the correlation exclusion region up to the length of the default sequence is zero, except for the central correlation peak. In addition, in each default sequence within a family of default sequences, the correlation function for all N consecutive copies of any other default sequences within that family has a cross-correlation exclusion region in the same region as the correlation exclusion region, where each point in the cross-correlation exclusion region is zero. That is, when a single sequence in a family of default sequences is correlated with its own template, this sequence produces a strong correlation peak surrounded by a zero region. However, when any member of a family of sequences is cross-correlated with the template of another member of the same family of sequences, there is no correlation peak, and a zero region exists in the same exclusion region. The N consecutive copies of the correlation function may be alternately multiplied by -1, that is, every other of the N consecutive copies may be inverted.

[0032] Each default sequence within a family of default sequences may be a circularly shifted copy of that default sequence. The default sequence can be used in this manner and is selected or generated to have the correlation properties described herein. Because an exclusion region surrounds the correlation peak, by circularly shifting a copy of the default sequence to generate an additional default sequence in the family of default sequences, two default sequences in the same family will indicate zero correlation within the exclusion region when cross-correlated with respect to each other's templates. Each default sequence within a family of default sequences may be an odd-period circularly shifted copy of that default sequence; that is, each circularly shifted element may be inverted during the shift process.

[0033] The amount of shift when generating a new sequence by circularly shifting the initial sequence can be determined by the sequence number and M elements within the range of the default sequence family, where M may be any integer greater than 1, and M controls the duration of the exclusion region in the filtered signal. For example, if the initial sequence has 500 elements, the sequence may be shifted between 1 and 500 before the sequence is repeated. Thus, the maximum size of the family can be determined by the length of the sequence relative to the size of M. seq In the example where =500, the maximum family size is 5. Since the number of sequences that can be obtained within a family range is determined by the length of the first sequence, the length of the first default sequence can be configured to be the product of the number of transducers and M. In this way, the sequence lengths and the family size of the sequences can be configured to correspond to the number of transducers that can be operated simultaneously and non-interferingly. Each sequence can then be generated by shifting the first sequence by the product of the sequence number within the family range multiplied by M.

[0034] Each default sequence within a family of default sequences can be generated using odd-period multiplication of a primor sequence to a modified extended Hadamard matrix. A primor sequence can be defined as having M elements, where M is an integer greater than 1, and the size of the extended Hadamard matrix can be chosen to generate a family of default sequences greater than the number of transducers used by the ultrasonic device. In this way, the length of the sequences and the size of the family of sequences can be configured to correspond to the number of transducers that can be operated simultaneously and non-interferingly.

[0035] By using a unique sequence for each of the multiple transducers, a complete matrix of ultrasonic signal data can be recorded simultaneously. Each transmit signal is applied to each transducer, and then the received signal of each transducer is recorded, including the drive signal of the transducer itself and all the return ultrasonic energy incident on the transducer. Each transmit signal is formed as a template by concatenating the transmit signal N times. Then, a pulse-echo signal can be reconstructed for each transducer, which can be done by matching the received signal from the transducer with the template of the transducer itself, extracting a region from J times to J+1 times the transmit signal length from the correlation result, and thus generating F pulse-echo signals for F transducers. Then, the received signal of each transducer is filtered against the templates for each of the multiple transducers, extracting a region from J times to J+1 times the transmit signal length from the correlation result, and thus reconstructing the transmission ultrasonic energy that would have propagated between each pair of transducers, and thus (F 2 -F) pitch catch signals are generated.

[0036] The ultrasonic device may include an analog-to-digital (A / D) converter 214 configured to supply a digital output signal corresponding to a voltage measurement at terminal 216. In this way, the processor 202 can interpret the received signal 222 in digital form. The A / D converter 214 is configured to have a measurable voltage range larger than the peak voltage output of the electrical driver 204. In this way, the receiver 208 can measure the entire transmitted signal 220 and therefore the entire received signal 222 without any cutoff.

[0037] [Implementation Method] In an implementation of the present invention, a method is provided for transmitting and receiving RF signals in a medium, the method comprising the steps of driving a transceiver element configured to apply a radio frequency (RF) signal to the medium, and simultaneously driving the transceiver element and measuring the response of the transceiver element to the RF signal received from the medium. The radio frequency will be found to be in the range of 20 kHz to about 300 GHz. While this disclosure presents a system and method using hardware specifically for ultrasound, the same system and method can be applied to other types of radiation, such as electromagnetic radiation. In the embodiments described herein, ultrasound is considered to cover sound waves operating in the range of 20 kHz to several hundred MHz.

[0038] The drive step and the simultaneous response measurement step can be performed without switching between driving the transceiver elements and measuring the response of the transceiver elements. As described in this document, avoiding switching between driving the transceiver elements or transducers and measuring the response of the transceiver elements or transducers avoids the cost, size, power, and complexity of switching circuits and high-voltage hardware. The drive step and the simultaneous response measurement step can be performed without isolation or separation between the driver and the receiver. For example, a nonlinear isolation circuit becomes unnecessary. The driver and receiver can be in continuous electrical contact.

[0039] Measuring the response of transceiver elements may include the step of converting the analog signal from the transceiver elements into a digital signal that represents the analog signal. The conversion from analog to digital signal enables signal processing and the recovery of encoded information within the signal. The digital signal is selected to have a range that covers at least the entire range of the drive signal applied to the driver. This allows for a complete and uninterrupted capture of the entire range of measurements applied to and received from the transducer.

[0040] RF signals or ultrasonic signals can be modulated according to a predetermined sequence. Thus, the predetermined sequence is encoded within the ultrasonic signal or RF signal and can be reconstructed from the signal by demodulating it. The predetermined sequence can be modulated by any conventional modulation means, specifically, one or more of phase modulation, frequency modulation, and / or amplitude modulation.

[0041] As illustrated with respect to Figure 4, a default sequence can be constructed such that its correlation function with respect to the template signal has a correlation peak and an exclusion region of the same length as the default sequence (e.g., a predetermined window, a perfectly correlated response within the range of 503 in the example of Figure 4). More precisely, within the exclusion region, the correlation of the default sequence with respect to the template is zero. While many possible sequences can be generated to satisfy the conditions for a perfectly correlated response, one method for generating a suitable default sequence is described in detail below. It is important that the default sequence gives a response as defined herein, but it is not essential to use this exemplary method to generate such a sequence.

[0042] [Example of sequence generation] The following is an example of how a suitable sequence can be generated according to the present invention. However, it may be acknowledged that similar sequences that produce the same effects as the exemplary sequences described herein can be generated using other sequence generation methods.

[0043] The sequence shown in this example is a ternary sequence. Unlike a binary signal, which can take only two values, for example, 1 and 0, or +1 and -1, a ternary signal can take three values, in this example being +1, 0, and -1. An encoded ternary signal can consist of two components: 1) a control sequence (seq) and 2) a symbol (sym). Both the control sequence and the symbol have L elements, i.e., L seq and L sym It may be an array of three values.

[0044] Each element of the control sequence is repeated as a symbol, and the value of the control sequence controls the characteristics of the symbol. The characteristics of the symbol relate to the modulation of the sequence and can be frequency, phase, amplitude, or a combination thereof. In this example, they are the phase and amplitude of the symbol. Therefore, for a value of +1 in the control sequence, all symbol values ​​are multiplied by +1; for a value of -1, they are multiplied by -1; and for a value of 0, they are set to zero.

[0045] The data rate and symbols can be matched to the transducer bandwidth to achieve the best transmission efficiency. Symbol matching is achieved by setting the switching frequencies within a symbol to match the frequencies to which the transducer responds most effectively. That is, the transmitted signal may consist of modulated copies of symbols that match the operating frequency of the transducer.

[0046] The length and specific order in which the values ​​of the control sequence change determine the output characteristics after correlation. Any form of control sequence, even a randomly generated sequence, has an autocorrelation response that includes a large principal lobe or autocorrelation peak at zero-shift / time delay values ​​and side lobes (or noise or self-noise) at other time delays. It is desirable to achieve a large principal lobe such that side lobes are minimal or absent. In the authors' preferred embodiment, a control sequence is used that has a large principal lobe and no side lobes (i.e., theoretically perfect compression performance) within a range of some number of samples of the principal lobe. The region of zero values ​​between the principal lobe and the side lobes is called the exclusion region, and the number of samples in the exclusion region is L.ez can be defined as

[0047] This sequence can be generated using the generation of primitive polynomials according to the following formula.

Number

[0048] In the formula, s is the sequence, n is the element number of the sequence s, q is an odd prime number, ε is a primitive element of the extension field GF(q 2 ), and χ is the Legendre symbol (outputting 0 for input 0, 1 for input 1, and -1 for any other input). The element number n exists over the range from 0 to q.

[0049] 〔Control sequence family〕 An exemplary control sequence can be a family such that when each member is correlated with its corresponding template (i.e., the N concatenations of the member itself in the description of the preferred embodiment regarding FIG. 4), the same response, i.e., the same amplitude main lobe and the same length exclusion zone, is produced. On the other hand, if the control sequence is cross-correlated with the templates of other family members, the response becomes zero throughout the position of the main lobe and the entire exclusion zone. By ensuring that the sequence length has a sufficient length for a given exclusion zone and a sufficient length for the required SNR gain for a set family size of F members, the system can surely generate a signal that is of high quality for the measurement window of interest and completely removes cross-talk / interference between the measurement channels.

[0050] Figure 5 shows three correlated outputs of a sequence correlated to a fixed template. These sequences are created by circularly shifting the sequence of the first member of the family by the number of elements, and the template here is generated by concatenating the first sequence three times. In the case of Figure 5, two additional family members are created by circularly shifting the original sequence by 125 and 250 elements, respectively, in odd-periods. It is possible to circularly shift the original sequence to generate a large number of family members, partly because when correlated to a suitable template, it results in a perfectly correlated response in the excluded region of the sequence. For example, the correlated response of the original sequence that has been time-shifted or delayed by 125 sequence elements is zero, so circularly shifting the sequence elements by 125 produces a default code that contains the same elements at different positions that do not interfere with the signal of the original sequence. In this way, if the original sequence contains 503 elements, at least 503 separate sequence family members can be provided by circularly shifting the original sequence. A circular shift of a sequence can be achieved by assigning each sequence element to a new position. For example, the first element can be shifted to the position of the second, the second to the third, and so on. The last element of the sequence can cycle back to the position of the first element. For odd-periodic circular shifts, the last element can be inverted (i.e., multiplied by -1) before cycling back to the position of the first element. In this way, a number of family members of a sequence related to the original sequence can be provided.

[0051] With respect to Figures 6A and 6B, the advantages of creating multiple family members of default sequences according to this disclosure will be apparent. Figure 6A shows the first and second sequences within a family of circularly shifted default sequences. Sequence 1 is shown to have a perfect correlation response while also giving a zero response to any cross-correlation with sequences 2, 3, or 4. Sequence 2 is an odd-period circularly shifted sequence belonging to the same family as sequence 1. Similarly, sequence 2 also gives a zero response to any cross-correlation with sequences 1, 3, or 4, and gives a perfect correlation with its own template. Moving to Figure 6B, sequences 3 and 4 also give the same perfect autocorrelation response while also giving a zero response to any cross-correlation with any of the other sequences. This perfect correlation response, combined with the non-interference between members of the same family, means that many default sequences can be generated from a single original default sequence without requiring further generation of the original sequence. Furthermore, when members of default sequences from different families are cross-correlated, the chances of interference may be non-zero.

[0052] By providing circularly shifted default sequences as described in this book, a large number of different family members can be used for multiple sensors in an array. Default sequences of the same family do not cause mutual correlation interference, so the full dynamic range and the best possible signal-to-noise ratio for the hardware can be extracted while using the transducers that make up the array simultaneously.

[0053] The following is a non-exclusive list of the perspectives of this disclosure.

[0054] Viewpoint A1) An ultrasonic transducer having a terminal, and a driver that electrically communicates with the ultrasonic transducer via the terminal, A receiver that electrically communicates with the ultrasonic transducer via the aforementioned terminals. An ultrasonic device equipped with, An ultrasonic device in which the receiver is electrically in contact with the driver via the terminal, and the ultrasonic transducer is configured to simultaneously transmit and receive a modulation signal.

[0055] Optionally, the transmitted signal in viewpoint A1 is generated by the controller / driver, and the received signal corresponds to the ultrasonic response of the medium under test.

[0056] Viewpoint A2) The ultrasonic apparatus according to Viewpoint A1, wherein the receiver is configured to continuously measure the terminals of the ultrasonic transducer for the duration of the transmitted signal.

[0057] Viewpoint A3) The ultrasonic apparatus according to Viewpoint A2, wherein the receiver is configured to continuously measure the terminals of the ultrasonic transducer over an additional measurement period to constitute a received signal, and optionally the additional period is in the range of 0.1 to 1000 times the length of the transmitted signal.

[0058] Viewpoint A4) The ultrasonic apparatus according to any one of the above views, wherein the transmitted modulated signal is modulated according to a predetermined sequence, and the transmitted modulated characteristic is one of phase, frequency, or amplitude.

[0059] Viewpoint A5) The ultrasonic device according to Viewpoint A4, wherein the default sequence is a binary sequence that takes values ​​of 1 and -1, or a ternary sequence that takes values ​​of 0, 1, or -1.

[0060] Viewpoint A6) An ultrasonic apparatus according to any one of the above views, wherein the modulated component of the transmitted signal is a default symbol, the default symbol is matched in terms of frequency content to the frequency response of the ultrasonic transducer, the phase, frequency, or amplitude of repeated copies of the default symbol is modulated using the default sequence, the length of the default symbol is optionally configured to adjust the bandwidth of the transmitted modulated signal, and further optionally configured by the user to adjust the bandwidth of the transmitted modulated signal.

[0061] Viewpoint A7) The ultrasonic apparatus according to any one of the views above, wherein the transmitted modulated signal is applied to the transducer terminal the first time so that the predetermined sequence is used aperiodically.

[0062] Viewpoint A8) The ultrasonic apparatus according to any one of the above views, further comprising a processor in communication with the receiver, the processor configured to filter the received signal using a matched filter constructed from a corresponding template signal in order to generate an output signal.

[0063] Viewpoint A9) The ultrasonic apparatus according to Viewpoint A8, wherein the template signal is generated by concatenating N copies of the transmitted modulated signal.

[0064] Viewpoint A10) The ultrasonic device according to any one of Viewpoints A4 to A9, wherein the default sequence is constructed from two complementary Goley sequences separated by a fixed offset amount, the value of the default sequence within the range of the fixed offset amount is zero, and further optionally, the time difference (DTG) between the start of the first Goley sequence of the two complementary Goley sequences and the start of the second Goley sequence of the two complementary Goley sequences can be defined by the user.

[0065] Viewpoint A11) The ultrasonic apparatus according to Viewpoint A10, wherein the output signal is generated by shifting the matched filter result by the DTG to generate a shifted matched filter result, and adding the matched filter result to the shifted matched filter result.

[0066] Viewpoint A12) The ultrasonic device according to Viewpoint A9, wherein the default sequence is configured such that the correlation function for N consecutive copies of the sequence itself has an autocorrelation peak surrounded by an exclusion region, the exclusion region of the correlation function output is zero at all points except the central autocorrelation peak, and optionally, the N consecutive copies of the correlation function are alternately multiplied by -1.

[0067] Viewpoint A13) The ultrasonic apparatus according to Viewpoint A9, wherein the output signal is a selected region in the filter output that starts at J times the length of the transmitted modulated signal and ends at J+1 times the length of the transmitted modulated signal, where N is a positive integer greater than 1 and J is less than N, optionally.

[0068] Viewpoint A14) An ultrasonic apparatus according to any one of the above views, further comprising a plurality of ultrasonic transducers, each of which is configured to simultaneously transmit and receive a modulated signal, and which can be optionally operated simultaneously.

[0069] Viewpoint A15) The ultrasonic apparatus according to Viewpoint A14, wherein each of the plurality of ultrasonic transducers is configured to transmit a different modulation signal, and each different modulation signal includes a different default sequence within a family of default sequences.

[0070] Viewpoint A16) The ultrasonic device according to Viewpoint A15, wherein in each different default sequence within the family of default sequences, the correlation function for N consecutive copies of the sequence itself has an autocorrelation peak and an autocorrelation exclusion region, each point in the autocorrelation exclusion region is zero except for the central autocorrelation peak, and in each default sequence within the family of default sequences, the correlation function for N consecutive copies of each other default sequence within the family of default sequences has a cross-correlation exclusion region in the same region as the autocorrelation exclusion region, each point in the cross-correlation exclusion region is zero, and optionally, the N consecutive copies of the correlation function are alternately multiplied by -1.

[0071] Viewpoint A17) The ultrasonic device according to Viewpoint A16, when dependent on Viewpoint A12, wherein each default sequence in the family of default sequences is either a circular shift copy of the default sequence or an odd-period circular shift copy of the default sequence, and optionally, the shift is determined by the sequence number in the family of default sequences and the symbol width of M, where M is an integer between 1 and 10000, and the length of the first default sequence is configured to be the product of the number of transducers and M.

[0072] Viewpoint A18) The ultrasonic apparatus according to Viewpoint A16, as opposed to Viewpoint A12, wherein each default sequence in the family of default sequences is generated by odd-period multiplication of a primor sequence to a modified extended Hadamard matrix, the primor sequence being defined as the symbol width of M, where M is an integer between 1 and 10000, and the size of the extended Hadamard matrix is ​​configured to generate a family of default sequences greater than the number of transducers used by the ultrasonic apparatus.

[0073] Viewpoint A19) The ultrasonic apparatus according to any one of the above views, further comprising an analog-to-digital (A / D) converter configured to supply a digital output signal corresponding to a voltage measurement at the terminal, wherein the A / D converter is optionally configured to have a measurable voltage range greater than the peak voltage output of the electrical driver.

[0074] A20) A method for transmitting and receiving ultrasonic signals in a medium, A method comprising the steps of: driving an ultrasonic transducer configured to apply modulated ultrasonic waves to the medium; and simultaneously with driving the ultrasonic transducer, receiving the response of the medium under the application of the modulated ultrasonic signal.

[0075] Optionally, in the method described in viewpoint A20, the RF transducer is configured to transmit an RF signal into the medium under test while the modulated signal is being generated by the controller, and simultaneously with the driving of the RF transducer, the RF transducer is configured to receive a returned modulated RF signal corresponding to the response of the medium under test through the same RF transducer used for the transmission event.

[0076] Viewpoint A21) The method according to Viewpoint A20, wherein the step of receiving the response of the medium is performed continuously through the reception of the entire modulated ultrasonic signal from the medium.

[0077] Viewpoint A22) The method according to Viewpoint A20 or Viewpoint A21, wherein the transmitted modulated signal is modulated according to a predetermined sequence, and optionally, the transmitted modulated characteristic is one of phase, frequency, or amplitude.

[0078] Viewpoint A23) The step further includes defining the default sequence by generating elements of primitive polynomials of extensions of the prime Galois field to at least two powers, wherein the elements of the default sequence are defined according to the following equation:

number

[0079] In the formula, s is the default sequence, n is an element of the default sequence, and ε is the extension field GF(q 2 The method described in viewpoint A22, where n is a primitive element and exists in the range from 0 to q.

[0080] A method for transmitting and receiving ultrasonic signals in a medium, comprising the steps of: providing an ultrasonic device described in any one of A1 to A19; driving an ultrasonic transducer to apply a modulated ultrasonic signal to the medium; and simultaneously with driving the ultrasonic transducer, receiving the response of the medium under the application of the modulated ultrasonic signal.

[0081] Viewpoint A25) The method according to Viewpoint A20, further comprising the step of continuously measuring the terminals of the ultrasonic transducer over an additional measurement period to constitute a received signal, wherein the additional period is optionally in the range of 0.1 to 1000 times the length of the transmitted signal.

[0082] Viewpoint A26) The method according to any one of the views above, wherein the transmitted modulated signal is modulated according to a predetermined sequence, and the transmitted modulated characteristic is one of phase, frequency, or amplitude.

[0083] Viewpoint A27) The method according to Viewpoint A26, wherein the default series is a binary series that takes values ​​of 1 and -1, or a ternary series that takes values ​​of 0, 1, or -1.

[0084] Viewpoint A28) The method according to any one of the views above, wherein the modulated component of the transmitted signal is a default symbol, the default symbol is matched in terms of frequency content to the frequency response of the ultrasonic transducer, the phase, frequency, or amplitude of repeated copies of the default symbol is modulated using the default sequence, and optionally the length of the default symbol can be configured by the user to adjust the bandwidth of the transmitted modulated signal.

[0085] Viewpoint A29) The method according to any one of the views above, wherein the transmitted modulated signal is applied to the transducer terminal the first time so that the predetermined sequence is used aperiodically.

[0086] Viewpoint A30) The method according to any one of the above views, further comprising the step of filtering the received signal using a matched filter constructed from a corresponding template signal in order to generate an output signal.

[0087] Viewpoint A31) The method according to Viewpoint A30, wherein the template signal is generated by concatenating N copies of the transmitted modulated signal.

[0088] Viewpoint A32) The method according to any one of Viewpoints A26 to A31, wherein the default sequence is constructed from two complementary Goley sequences separated by a fixed offset amount, the values ​​of the default sequence within the range of the fixed offset amount are zero, and further optionally, the time difference (DTG) between the start of the first Goley sequence of the two complementary Goley sequences and the start of the second Goley sequence of the two complementary Goley sequences can be defined by the user.

[0089] Viewpoint A33) The method according to Viewpoint A32, wherein the output signal is generated by shifting the matched filter result by the DTG to generate a shifted matched filter result, and adding the matched filter result to the shifted matched filter result.

[0090] Viewpoint A34) The method according to Viewpoint A30, wherein the default series is configured such that the correlation function for N consecutive copies of the series itself has an autocorrelation peak surrounded by an exclusion region, the exclusion region of the correlation function output is zero at all points except the central autocorrelation peak, and optionally the N consecutive copies of the correlation function are alternately multiplied by -1.

[0091] Viewpoint A35) The method according to Viewpoint A30, wherein the output signal is a selected region at the filter output that starts at J times the length of the transmitted modulated signal and ends at J+1 times the length of the transmitted modulated signal, where N is a positive integer greater than 1 and J is less than N, optionally.

[0092] Viewpoint A36) The method according to any one of the above views, further comprising the step of driving a plurality of ultrasonic transducers, each of which is configured to simultaneously transmit and receive a modulated signal, and optionally, the plurality of ultrasonic transducers are operated simultaneously.

[0093] Viewpoint A37) The method according to Viewpoint A36, wherein each of the plurality of ultrasonic transducers is configured to transmit a different modulation signal, and each different modulation signal includes a different default sequence within a family of default sequences.

[0094] Viewpoint A38) The method according to Viewpoint A37, wherein in each different default series within the family of default series, the correlation function for N consecutive copies of the series itself has an autocorrelation peak and an autocorrelation exclusion region, each point in the autocorrelation exclusion region is zero except for the central autocorrelation peak, and in each default series within the family of default series, the correlation function for N consecutive copies of each other default series within the family of default series has a cross-correlation exclusion region in the same region as the autocorrelation exclusion region, each point in the cross-correlation exclusion region is zero, and optionally, the N consecutive copies of the correlation function are alternately multiplied by -1.

[0095] Viewpoint A39) The method according to Viewpoint A38, as dependent on Viewpoint A34, wherein each default sequence in the family of default sequences is either a circular shift copy of the default sequence or an odd-period circular shift copy of the default sequence, and optionally the shift is determined by the sequence number in the family of default sequences and the symbol width of M, where M is an integer between 1 and 10000, and the length of the first default sequence is configured to be the product of the number of transducers and M.

[0096] Viewpoint A40) The method of Viewpoint A16, as dependent on Viewpoint A12, wherein each default sequence in the family of default sequences is generated by odd-period multiplication of a primor sequence to a modified extended Hadamard matrix, the primor sequence being defined as the symbol width M, where M is an integer between 1 and 10000, and the size of the extended Hadamard matrix is ​​configured to generate a family of default sequences greater than the number of transducers used by the ultrasonic device.

[0097] Viewpoint A41) The method according to any one of the above views, further comprising the step of measuring the voltage at the terminal using an analog-to-digital converter, wherein the A / D converter is optionally configured to have a measurable voltage range greater than the peak voltage output of the electrical driver.

[0098] Viewpoint B1) An ultrasonic transducer having terminals for communication with a driver and a receiver, A driver that electrically communicates with the ultrasonic transducer via the aforementioned terminal, A receiver that electrically communicates with the ultrasonic transducer via the terminal and also electrically communicates with the ultrasonic driver via the terminal. An ultrasonic device comprising an ultrasonic transducer configured to simultaneously transmit and receive a modulation signal.

[0099] Viewpoint B2) The ultrasonic apparatus according to Viewpoint B1, wherein the receiver is configured to continuously measure the received modulated signal.

[0100] Viewpoint B3) The ultrasonic apparatus according to Viewpoint B1 or Viewpoint B2, wherein the receiver is configured to record the entire modulated signal, and optionally, the receiver is configured to record at least twice, at least ten times, or at least 1000 times the length of the entire modulated signal.

[0101] Viewpoint B4) The ultrasonic apparatus according to Viewpoint B1 or Viewpoint B2, wherein the receiver is configured to record a portion of the entire modulated signal, and optionally, the receiver is configured to record at least 0.1 times or 0.5 times the length of the entire modulated signal.

[0102] Viewpoint B5) The transmitted modulated signal is modulated according to a predetermined sequence, and optionally, the transmitted modulated signal is modulated in terms of phase, frequency, or amplitude, as described in any one of the above views, the ultrasonic apparatus.

[0103] Viewpoint B6) An ultrasonic apparatus according to any one of the above views, further comprising a processor in communication with the receiver, the processor being configured to process the received modulated signal to give an output indicating one or more characteristics of the received modulated signal.

[0104] Viewpoint B7) The ultrasonic apparatus according to Viewpoint B6, wherein one or more characteristics of the received modulated signal include amplitude, time of flight, and one or more frequency shifts of the received modulated signal relative to the transmitted modulated signal.

[0105] Viewpoint B8) The ultrasonic apparatus according to Viewpoint B6 or Viewpoint B7, wherein the processor is configured to process the received modulated signal by correlating the received modulated signal with a matching filter that includes N concatenations of the transmitted modulated signal.

[0106] Viewpoint B9) The ultrasonic device according to Viewpoint B8, wherein the predetermined series is configured such that the correlation function for the series itself has an autocorrelation peak and an exclusion region, and in the exclusion region the autocorrelation of the predetermined series is zero.

[0107] Viewpoint B10) The ultrasonic apparatus according to Viewpoint B6 or Viewpoint B7, wherein the processor is configured to process the received modulated signal by correlating the received modulated signal with a matching filter including the transmitted modulated signal in order to generate a correlation result, shifting the correlation result by an offset amount in order to create a shift result, and superimposing the correlation result and the shift result.

[0108] Viewpoint B11) The ultrasonic apparatus according to Viewpoint B10, wherein the default sequence is configured such that the correlation function for the corresponding matched filter has an autocorrelation peak and an exclusion region, in which the autocorrelation of the default sequence is zero, and the matched filter is constructed from two complementary Goley sequences separated by the offset amount.

[0109] Viewpoint B12) The ultrasonic apparatus according to Viewpoint B11, wherein the matching filter is constructed based on at least three connections of the default sequence such that the matching filter generates an autocorrelation peak and an exclusion zone, and in the exclusion zone the autocorrelation of the default sequence is zero.

[0110] Viewpoint B13) The ultrasonic device described in any one of Viewpoints B5 to B12, wherein the predetermined sequence is a non-periodic sequence.

[0111] Viewpoint B14) An ultrasonic device according to any one of Viewpoints B5 to B13, wherein the length of the predetermined sequence is adjustable by the user so that the signal-to-noise ratio of the output can be configured to show one or more characteristics of the received modulated signal.

[0112] Viewpoint B15) An ultrasonic apparatus according to any one of the above views, further comprising a plurality of ultrasonic transducers, each of which is configured to transmit and receive a modulated signal.

[0113] Viewpoint B16) The ultrasonic apparatus according to Viewpoint B15, wherein each of the plurality of ultrasonic transducers is configured to transmit a different modulation signal.

[0114] Viewpoint B17) The ultrasonic apparatus according to Viewpoint B16, wherein each different modulated signal is modulated according to a default sequence within a family of default sequences, and optionally, each default sequence within the family of default sequences is either a circularly shifted copy of the default sequence or an odd-period circularly shifted copy of the default sequence.

[0115] Viewpoint B18) An ultrasonic apparatus according to any one of the above views, further comprising an analog-to-digital (A / D) converter configured to supply a digital output signal corresponding to a voltage measurement at the terminal.

[0116] Viewpoint B19) The ultrasonic apparatus according to Viewpoint B18, wherein the A / D converter is configured to have a voltage range greater than the voltage range of the ultrasonic driver.

[0117] Viewpoint B20) A method for transmitting and receiving ultrasonic signals in a medium, The steps include driving an ultrasonic transducer configured to apply a modulated ultrasonic signal to the medium, The process involves simultaneously driving the ultrasonic transducer and receiving the response of the medium under the application of the modulated ultrasonic signal. A method for providing it.

[0118] Viewpoint B21) The method according to Viewpoint B20, wherein the step of receiving the response of the medium is performed continuously through the reception of the entire modulated ultrasonic signal.

[0119] Viewpoint B22) The method according to Viewpoint B20 or Viewpoint B21, wherein the modulated signal is modulated according to a predetermined sequence, and optionally, the modulated signal is modulated in terms of phase, frequency, or amplitude.

[0120] Viewpoint B23) The step further includes defining the default sequence by generating elements of primitive polynomials of extensions of the prime Galois field to at least two powers, wherein the elements of the default sequence are defined according to the following equation:

number

[0121] In the formula, s is the default sequence, n is an element of the default sequence, and ε is the extension field GF(q 2 The method described in viewpoint B22, where n is a primitive element and exists in the range from 0 to q. [Explanation of Symbols]

[0122] 100 Conventional Ultrasonic Systems 120, 220 ultrasonic energy 122,222 responses 200 Ultrasonic system according to the present invention 216 terminals

Claims

1. An ultrasonic transducer having terminals, and a driver that electrically communicates with the ultrasonic transducer via the terminals, A receiver that electrically communicates with the ultrasonic transducer via the aforementioned terminals. An ultrasonic device equipped with, An ultrasonic device in which the receiver is electrically in contact with the driver via the terminals, and the ultrasonic transducer is configured to simultaneously transmit and receive a modulation signal.

2. The ultrasonic apparatus according to claim 1, wherein the receiver is configured to continuously measure the terminals of the ultrasonic transducer for the duration of the transmitted signal.

3. The ultrasonic apparatus according to claim 1 or 2, wherein the receiver is configured to continuously measure the terminals of the ultrasonic transducer over an additional measurement period to constitute a received signal, and optionally the additional period is in the range of up to 1000 times the length of the transmitted signal.

4. The ultrasonic apparatus according to any one of the above claims, wherein the transmitted modulated signal is modulated according to a predetermined sequence, and the transmitted modulated characteristics include one or more of phase, frequency, or amplitude.

5. The ultrasonic apparatus according to claim 4, wherein the default sequence is a binary sequence that takes values ​​of 1 and -1, or a ternary sequence that takes values ​​of 0, 1, or -1.

6. The ultrasonic apparatus according to any one of the above claims, wherein the modulated component of the transmitted signal is a default symbol, the default symbol is matched in terms of frequency content to the frequency response of the ultrasonic transducer, the phase, frequency, or amplitude of repeated copies of the default symbol is modulated using the default sequence, and optionally the length of the default symbol is configured to adjust the bandwidth of the transmitted modulated signal.

7. The ultrasonic apparatus according to any one of the above claims, wherein the transmitted modulated signal is applied to the transducer terminal the first time such that the predetermined sequence is used aperiodically.

8. The ultrasonic apparatus according to any one of the above claims, further comprising a processor in communication with the receiver, the processor configured to filter the received signal using a matched filter constructed from a corresponding template signal in order to generate an output signal.

9. The ultrasonic apparatus according to claim 8, wherein the template signal is generated by concatenating N copies of the transmitted modulated signal, or the template signal is generated by concatenating N copies of a signal derived from the predetermined sequence, where N is a positive integer greater than 1.

10. The ultrasonic apparatus according to any one of claims 4 to 9, wherein the default sequence is constructed from two complementary Goley sequences separated by a fixed offset amount, the value of the default sequence within the range of the fixed offset amount is zero, and further optionally, a time difference (DTG) between the start of the first Goley sequence of the two complementary Goley sequences and the start of the second Goley sequence of the two complementary Goley sequences can be configured.

11. The ultrasonic apparatus according to claim 10, wherein the output signal is generated by shifting the matched filter result by the DTG to generate a shifted matched filter result, and adding the matched filter result to the shifted matched filter result.

12. The ultrasonic apparatus according to claim 9, wherein the default sequence is configured such that the correlation function for N consecutive copies of the sequence itself has an autocorrelation peak surrounded by an exclusion region, the exclusion region of the correlation function output is zero at all points except the central autocorrelation peak, and the N consecutive copies of the correlation function are alternately multiplied by -1, at the discretion of choice.

13. The ultrasonic apparatus according to claim 9, wherein the output signal is a selected region in the filter output that starts at J times the length of the transmitted modulation signal and ends at J+1 times the length of the transmitted modulation signal, and optionally N is a positive integer greater than 1 and J is less than N.

14. The ultrasonic apparatus according to any one of the above claims, further comprising a plurality of ultrasonic transducers, each of which is configured to simultaneously transmit and receive a modulated signal or a sum of modulated signals, and each of the plurality of ultrasonic transducers can be optionally operated simultaneously.

15. The ultrasonic apparatus according to claim 14, wherein each of the plurality of ultrasonic transducers is configured to transmit a different modulation signal, and each different modulation signal is created from a different default sequence within a family of default sequences.

16. The ultrasonic apparatus according to claim 15, wherein in each different default sequence within the family of default sequences, the correlation function for N consecutive copies of the sequence itself has a correlation peak and an exclusion region, each point in the exclusion region is zero except for the central correlation peak, and in each default sequence within the family of default sequences, the correlation function for N consecutive copies of each other default sequence within the family of default sequences has a cross-correlation exclusion region in the same region as the autocorrelation exclusion region, each point in the cross-correlation exclusion region is zero, and optionally, the N consecutive copies of the correlation function are alternately multiplied by -1.

17. The ultrasonic apparatus according to claim 16 when dependent on claim 12, wherein each default sequence in the family of default sequences is either a circular shift copy of the default sequence or an odd-period circular shift copy of the default sequence, and optionally the shift is determined by the sequence number in the family of default sequences and M elements, where M is an integer greater than 1, and the length of the first default sequence is configured to be the product of the number of transducers and M.

18. The ultrasonic apparatus according to claim 16, as dependent on claim 12, wherein each default sequence in the family of default sequences is generated by odd-period multiplication of a primor sequence to a modified extended Hadamard matrix, the primor sequence is defined as the symbol width of M, where M is an integer greater than 1, and the size of the extended Hadamard matrix is ​​configured to generate a family of default sequences greater than the number of transducers used by the ultrasonic apparatus.

19. The ultrasonic device according to any one of claims 14, 15, or 16, wherein F pulse-echo output signals are generated by the ultrasonic device, where F is the number of transducers used, and the device is configured to filter the received signals from each transducer by a template signal of the signal itself, wherein the unique template signal of each transducer includes N sequences of the transducer's transmitted signals or N sequences of signals derived from a predetermined sequence of the transducer, and the pulse-echo output signals are taken from the filtering result to be in a region between J and J+1 times the length of the transmitted signal.

20. By filtering the received signals from each transducer with the respective template signals for each other transducer, (F ２ The ultrasonic apparatus according to any one of claims 14, 15, 16, or 19, wherein F transmitted signals are generated, and the transmitted output signals are taken from each filtered result as a region between J and J+1 times the length of the transmitted signal, thereby generating a complete matrix of ultrasonic data from a single transmission event in which all transducers are operated simultaneously.

21. The ultrasonic apparatus according to any one of the above claims, further comprising an analog-to-digital (A / D) converter configured to supply a digital output signal corresponding to a voltage measurement at the terminal, wherein the A / D converter is optionally configured to have a measurable voltage range greater than the peak voltage output of the electrical driver.

22. A method for transmitting and receiving radio frequency (RF) signals in a medium, A method comprising the steps of: driving an RF transducer configured to apply a modulated RF signal to the medium; and simultaneously with driving the RF transducer, receiving the modulated RF signal and the response of the medium under the application of the modulated RF signal.

23. The method according to claim 22, wherein the step of receiving the response of the medium is performed continuously over the entire duration of the modulated RF signal transmitted from the driver, and optionally over an additional measurement period to constitute the received signal, the duration of which is in the range of 1 to 1001 times the length of the transmitted signal.

24. The method according to claim 22, wherein the step of receiving the response of the medium is performed continuously through the reception of the entire modulated RF signal from the medium and, optionally, over an additional measurement period to constitute the received signal, the period of reception being in the range of 1 to 1001 times the length of the transmitted signal.

25. The method according to any one of claims 22 to 24, wherein the transmitted modulated signal is modulated according to a predetermined sequence, and optionally the transmitted modulated characteristics include one or more of phase, frequency, or amplitude.

26. The process further includes the step of defining the default sequence by generating elements of primitive polynomials of extensions of the prime Galois field up to at least two powers, wherein the elements of the default sequence are defined according to the following equation: [Math 4] In the formula, s is the default sequence, n is an element of the default sequence, and ε is the extension field GF(q) generated from quadratic primitive polynomials in q. ２ The method according to claim 25, wherein χ is a primitive element of ), where χ is the Legendre symbol (outputting 0 for input 0, 1 for input 1, and -1 for any other input), and n exists in the range from 0 to q.

27. The method according to any one of claims 22 to 26, wherein the RF signal is an ultrasonic signal, the RF transducer is an ultrasonic transducer, and the modulated RF signal is a modulated ultrasonic signal.

28. A method for transmitting and receiving an RF signal in a medium, comprising the steps of: providing an RF device according to any one of claims 1 to 21; driving an RF transducer to apply a modulated RF signal to the medium; and simultaneously with driving the RF transducer, receiving the response of the medium under the application of the modulated RF signal.

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