Variable frequency circuit, wireless tag circuit, device, system, and communication method

Abstract

The application discloses a frequency conversion circuit, a wireless tag circuit, a device, a system and a communication method. The application combines frequency division multiple access and time division multiple access technology, divides tags in the communication coverage of a reader into multiple uplink sub-bands, each sub-band can independently communicate with the reader without interference; meanwhile, time is divided into multiple time slots, and a plurality of specified sub-band tags communicate with the reader in the allocated time slots. After the communication tag capacity is improved to m*k by using the scheme, compared with only using time division polling technology, the communication tag capacity of the scheme is improved by m times.

Description

Technical Field

[0001] This invention relates to the field of wireless communication, and more specifically, to frequency conversion circuits, wireless tag circuits, devices, systems, and communication methods. Background Technology

[0002] Existing passive wireless frequency converter terminals typically employ time-division polling technology, such as... Figure 1 As shown in the diagram, during operation, the reader transmits a downlink radio frequency signal with a carrier frequency of f0. Assuming there are k passive wireless frequency-converting tags within its communication coverage area, all with a return frequency of f1, and the time slot for time-division polling is ΔT, then the total time required to complete one round of polling for the k tags within the communication coverage area is k*ΔT. When there are many tags within the communication coverage area, using only time-division polling technology results in a long time consumption and low communication efficiency, making it difficult to meet the needs of many applications requiring high real-time communication. Furthermore, using only time-division polling technology also makes it difficult to increase the tag capacity (i.e., the maximum number of tags) within a communication cycle.

[0003] Existing passive wireless frequency conversion tags also use frequency division to distinguish them based on different tag return frequencies. However, due to the limitations of their tag circuit structure, when M different return frequencies are required, M different tag circuit structures are needed. Such a large number of tag circuit structures often require custom production, which is not suitable for mass production. Moreover, the production cost is high, and the scalability of the scenarios is poor, and the tag replaceability is poor. Summary of the Invention

[0004] This invention overcomes the shortcomings of the prior art and provides frequency conversion circuits, wireless tag circuits, devices, systems and communication methods, in order to solve at least one technical problem existing in the prior art.

[0005] One aspect of the present invention provides a frequency conversion circuit:

[0006] A frequency converter circuit includes a modulation element, a switchable narrowband filter array, a wideband filter, and a control unit; the modulation element is electrically connected to both the switchable narrowband filter array and the wideband filter; the control unit is electrically connected to the switchable narrowband filter array.

[0007] The control unit is configured to generate a configuration signal;

[0008] The switchable narrowband filter array includes M narrowband filters, each with a different second resonant frequency; where M is an integer not less than 2.

[0009] The switchable narrowband filter array is configured to select and anchor a target narrowband filter from the M narrowband filters in response to the configuration signal, wherein the operating bandwidth of the wideband filter covers the operating bandwidth of each narrowband filter.

[0010] A further technical solution is that the frequency conversion circuit includes one of the following:

[0011] Option 1:

[0012] The modulation element includes a first modulation port, a second modulation port, and a third modulation port, wherein the first modulation port is electrically connected to the antenna element, the second modulation port is electrically connected to the broadband filter, the third modulation port is electrically connected to the switchable narrowband filter array, and the control unit is electrically connected to the switchable narrowband filter array.

[0013] Option 2:

[0014] Based on the first scheme, the switchable resonant network is also electrically connected to the broadband filter.

[0015] The second circuit architecture can reduce the power loss of the radio frequency signal in the circuit, increase the power of the frequency conversion radio frequency signal, and correspondingly reduce the threshold of the radio frequency drive power emitted by the reader to the tag.

[0016] A further technical solution is that the switchable resonant network also includes an M-select-one sub-unit; wherein,

[0017] In Option 1, any of the following settings can be used:

[0018] The first port of each narrowband filter is electrically connected to the third modulation port, and the second port of each narrowband filter is electrically connected to the M-select subunit; the broadband filter is electrically connected to the second modulation port.

[0019] Alternatively, the M-select subunit is electrically connected to the third modulation port, and each narrowband filter is electrically connected to the M-select subunit; the broadband filter is electrically connected to the second modulation port.

[0020] In Option 2, any of the following settings can be used:

[0021] The first port of each narrowband filter is electrically connected to the third modulation port, and the second port of each narrowband filter is electrically connected to the M-select subunit; the first port of the broadband filter is electrically connected to the second modulation port, and the second port of the broadband filter is electrically connected to the second port of each narrowband filter.

[0022] Alternatively, the M-select subunit is electrically connected to the third modulation port, and the first port of each narrowband filter is electrically connected to the M-select subunit; the first port of the wideband filter is electrically connected to the second modulation port, and the second port of the wideband filter is electrically connected to the second port of each narrowband filter.

[0023] A further technical solution is that the narrowband filter adopts one of the following: LC parallel resonant circuit, LC series resonant circuit, and passive piezoelectric resonator;

[0024] The broadband filter employs one of the following: LC parallel resonant circuit, LC series resonant circuit, RF open circuit, and RF short circuit.

[0025] A further technical solution is that the passive piezoelectric resonator is one of the following: crystal resonator, ceramic resonator, surface acoustic wave piezoelectric resonator, or MEMS piezoelectric resonator.

[0026] A further technical solution is that the modulation element is one of a transistor, bipolar transistor, unipolar transistor, field-effect transistor, junction field-effect transistor, metal-oxide-semiconductor field-effect transistor, two-dimensional electron gas transistor, or high electron mobility transistor.

[0027] A further technical solution is that when the modulation element is a bipolar transistor, any of the following configurations are adopted: the first modulation port, the second modulation port, and the third modulation port are respectively the collector, the emitter, and the base; or they are respectively the emitter, the collector, and the base; or they are respectively the base, the emitter, and the collector.

[0028] When the modulation element is a unipolar transistor, any of the following configurations are adopted: the first modulation port, the second modulation port, and the third modulation port are respectively the drain, the source, and the gate, or respectively the source, the drain, and the gate, or respectively the gate, the source, and the drain.

[0029] A further technical solution is that the frequency conversion signal is drawn from the first modulation port, or simultaneously from the first modulation port and the second modulation port, or simultaneously from the second modulation port and the third modulation port, or simultaneously from the first modulation port and the third modulation port, or simultaneously from all three modulation ports.

[0030] A further technical solution is that the frequency converter circuit also includes sensing elements;

[0031] In Scheme 1, the sensing element adopts any of the following configuration methods:

[0032] Electrically connected to the first modulation port;

[0033] Electrically connected to the second modulation port;

[0034] Electrically connected to the third modulation port;

[0035] In Scheme 2, the sensing element adopts any of the following configuration methods:

[0036] Electrically connected to the first modulation port;

[0037] Electrically connected to the second modulation port;

[0038] Electrically connected to the third modulation port;

[0039] It is positioned as a bypass on the electrical signal transmission path between the switchable narrowband filter array and the wideband filter.

[0040] The sensing value of the sensing element will cause the frequency of the frequency conversion signal to shift. For each frequency conversion circuit, after the narrowband filter is selected, the frequency of the frequency conversion signal that it can generate without the connection of the sensing element is determined. The magnitude of the sensing value can be indirectly obtained by combining the magnitude of the frequency shift of the frequency conversion signal with the relationship between the previously calibrated sensing value and the frequency shift of the frequency conversion signal.

[0041] Another aspect of the present invention provides a communication method applied to the frequency converter circuit described above, comprising the following steps:

[0042] Input downlink radio frequency signal;

[0043] The control unit generates configuration signals;

[0044] A switchable narrowband filter array responds to the configuration signal to anchor the target narrowband filter;

[0045] Output uplink frequency conversion signal.

[0046] Another aspect of the present invention provides a wireless tag circuit, including an antenna unit and a frequency conversion circuit as described above, wherein the antenna unit is electrically connected to a first modulation port of a modulation element;

[0047] The antenna unit is configured to receive downlink radio frequency signals and transmit uplink frequency conversion signals.

[0048] Another aspect of the present invention provides a wireless tag device, including a housing and a frequency conversion circuit or a wireless tag circuit as described above, wherein all or part of the frequency conversion circuit or the wireless tag circuit is disposed in the housing.

[0049] Another aspect of the present invention provides a wireless tag system, including a reader and a plurality of wireless tag devices as described above;

[0050] The reader is used to send downlink radio frequency signals to the wireless tag device and to receive uplink frequency conversion signals returned by the wireless tag device that meet preset communication rules.

[0051] Another aspect of the present invention provides a wireless communication method, characterized in that the method is applied to a wireless tag circuit or a wireless tag device as described above, the method comprising the following steps:

[0052] The antenna unit receives downlink radio frequency signals;

[0053] The control unit generates configuration signals;

[0054] A switchable narrowband filter array responds to the configuration signal to anchor the target narrowband filter;

[0055] The antenna unit transmits uplink frequency conversion signals.

[0056] Another aspect of the present invention provides a wireless communication method applied to a reader, the method comprising the following steps:

[0057] Send downlink radio frequency signals;

[0058] Receive the uplink frequency conversion signal sent by the wireless tag circuit or the wireless tag device as described above;

[0059] The uplink frequency conversion signal is analyzed to obtain frequency conversion information.

[0060] Another aspect of the present invention provides a wireless communication method applied to a wireless tag system as described above, the method comprising the following steps:

[0061] The reader sends downlink radio frequency signals;

[0062] In a certain time slot, a number of wireless tag devices, not exceeding m, receive downlink radio frequency signals and send uplink frequency conversion signals to the reader. Other wireless tag devices within the reader's communication range do not send uplink frequency conversion signals. The carrier frequency of the uplink frequency conversion signal is different from that of the downlink radio frequency signal. Wherein, m is the maximum number of sub-bands that the reader can process at the same time.

[0063] The reader receives and parses each uplink frequency conversion signal to obtain the corresponding frequency conversion information.

[0064] Compared with the prior art, the present invention has at least the following beneficial effects:

[0065] This invention combines frequency division multiple access (FDMA) and time division multiple access (TDMA) technologies to significantly improve the efficiency of accessing wireless tags within the reader's communication coverage area and the communication tag capacity per unit time. Compared with using only time division polling technology, the communication tag capacity of this solution is increased by m times.

[0066] Compared to traditional frequency conversion circuits with only a single frequency offset, if there are M frequency division multiplexing (FDM) tags within the reader's communication coverage area, then M frequency conversion circuits with different single frequency offsets are required. In this case, traditional frequency conversion circuits with only a single frequency offset are not suitable for manufacturing into M frequency conversion circuits with different single frequency offsets, making them unsuitable for mass production, resulting in higher production costs, hindering supply chain simplification, and having poor scalability. Furthermore, the replaceability of frequency conversion circuits in the tags is poor. This solution uses a resonant network array to overcome the above shortcomings. By configuring a broadband filter array through the control unit, tags can be interchanged, exhibiting strong adaptability and scalability, and facilitating mass production at low cost.

[0067] In this invention, the operating bandwidth of the broadband filter is wider than that of the corresponding narrowband filter. In other words, the quality factor of the narrowband filter is higher than that of the broadband filter. This setting can reduce the debugging difficulty of the two resonant networks in the frequency converter circuit and improve the anti-aging and anti-interference capabilities of the frequency converter circuit. Attached Figure Description

[0068] Figure 1 This is a schematic diagram of the principle of an existing wireless tag system;

[0069] Figure 2 A schematic diagram of the wireless tag system is provided for this invention;

[0070] Figure 3 This is a schematic diagram of a frequency converter circuit structure according to one embodiment;

[0071] Figure 4 This diagram illustrates the relationship between the operating frequencies of narrowband and wideband filters.

[0072] Figure 5 This is a schematic diagram of a frequency converter circuit structure according to another embodiment;

[0073] Figure 6 This is a schematic diagram of a frequency converter circuit structure according to another embodiment;

[0074] Figure 7 This is a schematic diagram of a frequency converter circuit structure according to another embodiment;

[0075] Figure 8 This is a schematic diagram of a frequency converter circuit structure according to another embodiment;

[0076] Figure 9 This is a schematic diagram of a frequency converter circuit structure according to another embodiment;

[0077] Figure 10 This is a schematic diagram of a frequency converter circuit structure according to another embodiment;

[0078] Figure 11 This is a schematic diagram of a frequency converter circuit structure according to another embodiment;

[0079] Figure 12 This is a schematic diagram of a wireless tag system according to one embodiment.

[0080] In the diagram, 131-modulation element, 132-wideband filter, 133-switchable narrowband filter array, 1331-M-select sub-unit, 1332-narrowband filter, 134-control unit, 135-antenna unit, 136-sensing element, 200-reader, 300-wireless tag device. Detailed Implementation

[0081] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0082] For ease of understanding, the concepts and terms that may appear in this application are explained below.

[0083] Tags: Also known as electronic tags, smart tags, transponders, etc., they are typically composed of coupling elements and chips. Based on their function, they can be divided into identification tags and sensing tags; the former only provides identification functionality, while the latter provides both identification and sensing capabilities.

[0084] Reader: Also known as a reader / writer, reading device, transceiver, communicator, etc. It is typically used to read (and sometimes write) tag information. Readers can be handheld or stationary devices.

[0085] A carrier signal is a high-frequency signal that does not carry information itself but serves as the physical basis for transmitting low-frequency signals (such as voice and data). Modulation techniques can be used to add modulation to the amplitude, frequency, or phase of a baseband signal, forming a modulated carrier signal. Without a low-frequency signal, the amplitude and phase of a high-frequency signal are usually fixed. After a low-frequency signal is added, the amplitude or phase of the high-frequency signal changes with the amplitude of the low-frequency signal.

[0086] Downlink: For communication between a reader and a tag, it refers to the direction of signal flow from the reader to the tag. For a single tag or the frequency converter circuit within the tag, it refers to the direction of signal flow from outside the tag (or outside the frequency converter circuit) to inside the tag (or inside the frequency converter circuit).

[0087] Uplink: For communication between the reader and the tag, it refers to the direction of signal flow from the tag to the reader. For a single tag or the frequency converter circuit within the tag, it refers to the direction of signal flow from inside the tag (or inside the frequency converter circuit) to outside the tag (or outside the frequency converter circuit).

[0088] On the one hand, in order to increase the tag capacity within the communication cycle and improve the reliability of wireless communication, this application combines frequency division multiple access and time division multiple access to significantly improve the access efficiency of wireless tags within the reader's communication coverage area and the tag capacity within the communication cycle.

[0089] On the other hand, this application achieves the purpose of this application by integrating frequency division and time division multiple access technologies based on the same wireless tag circuit, thereby enabling tags to be interchangeable, having high reliability, strong anti-interference ability, strong scene adaptability and scalability, dynamic configuration of frequency conversion, and facilitating mass production and low-cost production.

[0090] Please refer to Figure 2 , Figure 2 The technical principle of this invention is illustrated as follows: Tags within the reader's communication coverage area (elliptical dashed line) are divided into multiple uplink sub-bands. Each sub-band can communicate independently with the reader without interference. Simultaneously, time is divided into multiple time slots, and tags in several designated sub-bands communicate with the reader within their assigned time slots. Assume there are k time slots and m sub-bands (assuming the center frequencies of the sub-bands are f1, f2, ..., f...). m If the communication tag capacity during a communication cycle using only time-division polling technology is k, then the communication tag capacity using this scheme is m*k. In other words, compared to using only time-division polling technology, this scheme increases the communication tag capacity by a factor of m.

[0091] To achieve the objective of this invention, the present invention provides an embodiment of a frequency converter circuit, please refer to... Figure 3 The frequency converter circuit includes a modulation element 131, a switchable narrowband filter array 133, a wideband filter 132, and a control unit 134.

[0092] The frequency converter circuit includes two circuit architectures;

[0093] In Scheme 1, the modulation element 131 includes a first modulation port, a second modulation port and a third modulation port, wherein the first modulation port receives downlink radio frequency signals, the second modulation port is electrically connected to the switchable narrowband filter array 133, the third modulation port is electrically connected to the wideband filter 132, and the control unit 134 is electrically connected to the switchable narrowband filter array 133.

[0094] In Scheme Two, based on Scheme One, the switchable resonant network 132 is also electrically connected to the broadband filter 132. Figure 3 (Indicated by the dashed line). Compared with Scheme 1, Scheme 2 can reduce the power loss of the radio frequency signal in the circuit, increase the power of the frequency conversion signal, and correspondingly reduce the threshold of the radio frequency drive power transmitted by the reader to the tag.

[0095] The second modulation port and the third modulation port of the modulation element 131 are electrically connected to the switchable narrowband filter array 133 and the wideband filter 132, respectively, and the control unit 134 is electrically connected to the switchable narrowband filter array 133.

[0096] The modulation element 131 is used to receive a downlink radio frequency signal (e.g., its frequency is f0) and generate an uplink frequency conversion signal (e.g., its frequency is f). m In this configuration, the carrier frequencies of the uplink frequency-converted signal and the downlink radio frequency signal are different. It should be noted that the first port P1 of the modulation element 131 receives the downlink radio frequency signal, and the generated frequency-converted radio frequency signal exhibits isotropic or direction-independent transmission characteristics within the modulation element 131. Therefore, from the perspective of all three ports of the modulation element 131, frequency-converted radio frequency signals exist simultaneously. Thus, depending on actual needs, a signal output channel can be set to output the frequency-converted radio frequency signal simultaneously from all three ports, or the frequency-converted radio frequency signal can be output simultaneously from any two of the three ports, or the frequency-converted radio frequency signal can be output from one of the three ports.

[0097] Control unit 134 is configured to generate configuration signals;

[0098] The broadband filter 132 has a first resonant frequency (f r1 );

[0099] The switchable narrowband filter array 133 includes several narrowband filters and an M-to-1 sub-unit 1331, wherein the second resonant frequency (f) of each narrowband filter is... r2 The bandwidth of the broadband filter 132 is different from that of each narrowband filter; the M-select subunit 1331 anchors the target narrowband filter according to the configuration signal of the control unit 134.

[0100] It is understandable that the aforementioned "anchoring" refers to the stable selection of the M-selector sub-unit on the target narrowband filter, or in other words, the stable conduction connection between the M-selector sub-unit and the target narrowband filter. Specifically, in practical applications, after determining the required frequency conversion frequency, the frequency conversion circuit often needs to maintain that operating frequency for a long time until a new configuration signal is received.

[0101] Once a narrowband filter is selected, the frequency-converted radio frequency signal (frequency f) m The downlink radio frequency signal (frequency f0) and the selected second resonant frequency (f r2 The resonant signal is obtained by mixing in the modulation element 131, and the frequency relationship of the three is: f m =f0±n·f r2, where n is a positive integer. For details on the working principle, please refer to the prior application (application number: CN202411053036.6, invention title: A passive frequency conversion structure, sensor, method and system).

[0102] Due to the configurability of the frequency converter circuit, the frequency of the frequency converter signal output by the frequency converter circuit can be flexibly selected, set, switched and other configuration operations through software as needed. As a result, the tags formed based on the frequency converter circuit of this application have the following characteristics, including but not limited to: tags can be replaced with each other, tags have high reliability, strong anti-interference ability, strong scene adaptability and scalability, the frequency converter frequency can be dynamically configured, and it is conducive to mass production and low cost.

[0103] Understandably, the control unit 134 has a storage function, which can store the configuration data of the frequency converter circuit. Each frequency converter circuit stores preset configuration parameters at the factory and supports dynamic modification of the preset configuration parameters during operation.

[0104] For example, suppose a certain type of frequency converter circuit has three different second resonant frequencies (e.g., f0). r2-1 f r2-2 f r2-3 Accordingly, it has three different first resonant frequencies f r1-1 f r1-2 f r1-3 As mentioned above, this type of frequency converter circuit can output three different frequency converter signals (assuming n=1, and only the down-converter signal is selected), namely: f1=f0-f r2-1 f2 = f0 - f r2-2 f3 = f0 - f r2-3 When this type of frequency converter circuit is used in five operating scenarios (e.g., points 1 to 5), where points 1, 4, and 5 need to operate at frequency converter frequency f1, point 2 needs to operate at frequency converter frequency f2, and point 3 needs to operate at frequency converter frequency f3, then only five frequency converter circuits of this type (e.g., frequency converter circuits A to E) need to be used. The switchable narrowband filter array 132 is configured through the control unit 134 in each frequency converter circuit. Specifically, the switchable narrowband filter array 132 in the three frequency converter circuits (frequency converter circuits A, B, and C) used for points 1, 4, and 5 is switched to the first resonant frequency f1. r1-1 The narrowband filter switches the switchable narrowband filter array 132 in the frequency converter circuit D used at point 2 to the first resonant frequency f. r1-2 The narrowband filter switches the switchable narrowband filter array 132 in the frequency converter circuit E at point 3 to the first resonant frequency f. r1-3 Narrowband filter.

[0105] In practical applications, it may be necessary to move the frequency converter circuit from one point to another, for example, from point 4 to point 3 of frequency converter circuit B. In order to obtain the best electromagnetic performance, frequency converter circuit B needs to switch from the frequency conversion frequency f1 to f3. For the frequency converter circuit of this application, it is only necessary to switch the switchable narrowband filter array 132 in frequency converter circuit B to the first resonant frequency f1. r1-3 A narrowband filter is sufficient. However, in existing technologies, because the same tag circuit cannot achieve frequency switching, the result is either poor performance or the use of a different type of tag circuit to obtain better performance.

[0106] Please refer to Figure 4 , Figure 4 This diagram illustrates the spectral relationship between a broadband filter and various narrowband filters, where the horizontal axis represents frequency and the vertical axis represents amplitude. r1 f is the center frequency of the operating band of the broadband filter. r2-1 ... f r2-m These are the center frequencies of the operating frequency bands of each narrowband filter. The operating frequency band of the broadband filter covers the operating frequency band of each narrowband filter, or at least, the center frequencies of the operating frequency bands of each narrowband filter should fall within the operating frequency band of the broadband filter. From another perspective, the quality factor of a narrowband filter is higher than that of a broadband filter. This configuration reduces the difficulty of debugging the two resonant networks in the frequency converter circuit, and improves the frequency converter circuit's resistance to aging (e.g., operating frequency shift caused by natural performance degradation during the component's lifespan) and interference resistance (e.g., operating frequency shift caused by environmental fluctuations).

[0107] It should be noted that, Figure 4 The spectral curves of the broadband filter and each narrowband filter in the circuit can be either reflection or transmission spectra, depending on the structure of the frequency converter circuit. For example, when both the broadband filter and each narrowband filter are reflection type, they will both be reflection spectrum curves; when both the broadband filter and each narrowband filter are transmission type, they will both be transmission spectrum curves.

[0108] It should be noted that, under normal circumstances, the center frequency of the filter's operating frequency band is consistent with the carrier frequency of the radio frequency to meet the requirements of signal gating and anti-interference. For example, for a broadband filter, its center frequency is consistent with the first resonant frequency; for each narrowband filter, its center frequency is consistent with the corresponding second resonant frequency.

[0109] The operating frequency bands of adjacent narrowband filters can be completely non-overlapping or partially overlapping. When they partially overlap, a frequency guard band of a certain width is usually set. The operating frequency bands of adjacent wideband filters need to be comprehensively considered based on the frequency demodulation cost at the reader end. The demodulation cost here includes the difficulty and cost of separating adjacent frequencies in hardware, the difficulty and cost of parsing adjacent frequencies in software, and the real-time performance of demodulation, etc.

[0110] Figure 5 Provided based on Scheme 1 ( Figure 3 The specific structure of the frequency converter circuit in the illustrated embodiment includes a switchable narrowband filter array 133 comprising M narrowband filters and an M-select subunit 1331, where M is an integer not less than 2; each narrowband filter has a different second resonant frequency; a control unit 134 is electrically connected to the M-select subunit 1331; the first port of each narrowband filter is electrically connected to the third port of the modulation element 131; the second port of each narrowband filter is selectively electrically connected to the M-select subunit 1331, which is used to select a specific narrowband filter according to the instructions of the control unit 134. In the aforementioned second circuit architecture, in this embodiment, the second port of the wideband filter 132 is electrically connected to the M-select subunit 1331.

[0111] Figure 6 Provided based on Scheme 1 ( Figure 3 The frequency converter circuit structure shown in the embodiment is in Figure 3 Based on this, the switchable narrowband filter array 133 includes M narrowband filters and an M-select subunit 1331, where M is an integer not less than 2; the second resonant frequencies of each narrowband filter are different; the control unit 134 is electrically connected to the M-select subunit 1331, the M-select subunit 1331 is electrically connected to the third modulation port of the modulation element 131, and the first port of each narrowband filter is switchably electrically connected to the M-select subunit 1331; the M-select subunit 1331 is used to select a specific narrowband filter according to the instructions of the control unit 134. For the aforementioned second-scheme circuit architecture, in this embodiment, the second port of the broadband filter 132 is electrically connected to the second port of each narrowband filter.

[0112] The following will use a specific circuit structure for explanation.

[0113] Figure 7 The specific implementation circuit of the frequency converter is given. Figure 5Based on this, the switchable narrowband filter array 133 includes an M-to-one subunit 1331 and M passive piezoelectric resonators 1332-1, 1332-2, ..., 1332-m. The M-to-one subunit 1331 is a switching circuit that can realize the M-to-one function. The first port of each passive piezoelectric resonator is electrically connected to the third modulation port of the modulation element 131. The first port of the switching circuit is switchably electrically connected to the second port of each passive piezoelectric resonator, and the second port of the switching circuit is grounded. The broadband filter 132 adopts an LC parallel resonant circuit, which includes an inductor 1322 and a capacitor 1323. The first ends of the inductor 1322 and the capacitor 1323 are electrically connected to the second modulation port of the modulation element 131, and the second ends of the inductor 1322 and the capacitor 1323 are grounded. In this embodiment, the broadband filter 132 and each narrowband filter are reflective. Accordingly, Figure 4 The spectral curves are all reflection spectral curves.

[0114] It is important to note that the broadband filter here is in contrast to the switchable narrowband filter array. It is sufficient to ensure that the operating bandwidth of the broadband filter covers the operating bandwidth of each narrowband filter.

[0115] In some other embodiments, the broadband filter 132 can be any other suitable passive filter circuit, including but not limited to LC series resonant circuits, RF open circuits, and RF short circuits.

[0116] In some other embodiments, each narrowband filter can be any other suitable passive filter circuit, including but not limited to LC parallel resonant circuits, LC series resonant circuits, etc.

[0117] Figure 8 An embodiment of a frequency converter circuit structure is given, in Figure 5 Based on this, the switchable narrowband filter array 133 includes an M-to-1 subunit 1331 and three narrowband filters 1332-1, 1332-2, and 1332-3. The M-to-1 subunit 1331 is a switching circuit capable of performing a three-to-one selection. The first terminal of each narrowband filter is electrically connected to the third port of the modulation element 131, and the first terminal of the switching circuit can be switched to be electrically connected to the second terminal of each narrowband filter. Among them, narrowband filters 1332-1 and 1332-2 are both passive piezoelectric resonators, and narrowband filter 1332-3 is an LC series resonant circuit. The second resonant frequencies of the three narrowband filters are f1, f2, f3, f4, f5, f6, f7, f8, f9, f10, f11, f2, f3, f11, f2, f3, f4, f5, f6, f7, f8, f9, f11, f2 ... r2-1 f r2-2 f r2-3 The broadband filter 132 employs an LC parallel resonant circuit, which includes an inductor 1322 and a capacitor 1323, with a first resonant frequency of f. r1Its operating bandwidth covers the operating bandwidth of the three narrowband filters; the first terminals of inductor 1322 and capacitor 1323 are both electrically connected to the second modulation port of modulation element 131, and the second terminals of inductor 1322 and capacitor 1323 are both grounded; the second terminal of the switching circuit is electrically connected to the first terminals of inductor 1322 and capacitor 1323. In this embodiment, the broadband filter 132 and each narrowband filter are transmissive, and correspondingly, Figure 4 The spectral curves are all transmission spectral curves. Since most or all of the radio frequency signals selected by the broadband filter 132 do not pass through the second modulation port of the modulation element 131, but directly reach the selected narrowband filters, the power loss of the radio frequency signal in the modulation element 131 can be reduced, the power of the frequency conversion radio frequency signal can be increased, and the radio frequency drive power threshold transmitted by the reader to the tag can be reduced accordingly.

[0118] Figure 8 A specific implementation circuit of the frequency conversion circuit is given. In this embodiment, the modulation element 131 is a heterojunction bipolar transistor, with its first modulation port P1 being the collector, the second modulation port being the emitter, and the third modulation port being the base.

[0119] It should be noted that in any of the above embodiments, the modulation element can be a transistor, such as a bipolar transistor or a unipolar transistor.

[0120] In some embodiments, the unipolar transistor is preferably a field-effect transistor. The field-effect transistor is preferably a junction field-effect transistor (JFET), a metal-oxide-semiconductor field-effect transistor (MOSFET), a two-dimensional electron gas transistor, or a high electron mobility transistor (HEMT).

[0121] In some embodiments, the modulation element is a field-effect transistor, with a first modulation port as the drain, a second modulation port as the source, and a third modulation port as the gate. The frequency conversion signal is drawn from the first modulation port, or simultaneously from the first modulation port and the second modulation port, or simultaneously from the second modulation port and the third modulation port, or simultaneously from the first modulation port and the third modulation port, or simultaneously from all three modulation ports.

[0122] In some embodiments, the modulation element is a field-effect transistor, with a first modulation port as the source, a second modulation port as the drain, and a third modulation port as the gate. The frequency conversion signal is drawn from the first modulation port, or simultaneously from the first modulation port and the second modulation port, or simultaneously from the second modulation port and the third modulation port, or simultaneously from the first modulation port and the third modulation port, or simultaneously from all three modulation ports.

[0123] In some embodiments, the modulation element is a field-effect transistor, with a first modulation port as the gate, a second modulation port as the source, and a third modulation port as the drain. The frequency conversion signal is drawn from the first modulation port, or simultaneously from the first modulation port and the second modulation port, or simultaneously from the second modulation port and the third modulation port, or simultaneously from the first modulation port and the third modulation port, or simultaneously from all three modulation ports.

[0124] In some embodiments, the modulation element is a heterojunction bipolar transistor, with a first modulation port as the collector, a second modulation port as the emitter, and a third modulation port as the base. The frequency conversion signal is drawn from the first modulation port, or simultaneously from the first modulation port and the second modulation port, or simultaneously from the second modulation port and the third modulation port, or simultaneously from the first modulation port and the third modulation port, or simultaneously from all three modulation ports.

[0125] In some embodiments, the modulation element is a heterojunction bipolar transistor, with a first modulation port as the emitter, a second modulation port as the collector, and a third modulation port as the base. The frequency conversion signal is drawn from the first modulation port, or simultaneously from the first modulation port and the second modulation port, or simultaneously from the second modulation port and the third modulation port, or simultaneously from the first modulation port and the third modulation port, or simultaneously from all three modulation ports.

[0126] In some embodiments, the modulation element is a heterojunction bipolar transistor, with a first modulation port as the base, a second modulation port as the emitter, and a third modulation port as the collector. The frequency conversion signal is drawn from the first modulation port, or simultaneously from the first modulation port and the second modulation port, or simultaneously from the second modulation port and the third modulation port, or simultaneously from the first modulation port and the third modulation port, or simultaneously from all three modulation ports.

[0127] In this embodiment, the M-select subunit is a switching circuit capable of performing a three-to-one selection function, and it operates under the instructions of the control unit 134. For example, when the frequency converter circuit needs to provide a frequency of f... r2-2 When the second resonant frequency participates in the mixing to obtain the corresponding frequency conversion signal, the M-select subunit is electrically connected to the passive piezoelectric resonator 1332-2, so that the second resonant signal of the passive piezoelectric resonator 1332-2 is mixed to obtain the frequency conversion radio frequency signal. The operation follows the same logic when the frequency conversion circuit needs to provide a second resonant frequency of other frequencies for mixing. With this configuration, each frequency conversion circuit can provide M different frequency conversion signal frequencies f. m When setting up a scene, the frequency conversion circuit hardware structure of multiple tags is exactly the same. Only the control unit 134 of the tag needs to be adapted to the software side, which greatly improves the replaceability between tags and the scene adaptability and flexibility of the tags.

[0128] In some embodiments, the frequency converter circuit further includes a sensing element 136, which may be located in multiple positions. For example, the sensing element 136 may be located at a position electrically connected to one of the three ports of the modulation element 131; or the sensing element 136 may be located on the bypass of the signal transmission path electrically connected between the broadband filter 132 and the switchable narrowband filter array 133.

[0129] When the sensing element 136 is positioned to be electrically connected to one of the three ports of the modulation element 131, specifically, the sensing element 136 is electrically connected to the first port of the modulation element 131; or, the sensing element 136 is electrically connected to the second port of the modulation element 131; or, the sensing element 136 is electrically connected to the third port of the modulation element 131. In this case, the sensing quantity of the sensing element 136 will cause a frequency shift in the frequency of the frequency-converting radio frequency signal. For each frequency conversion circuit, after the narrowband filter is selected, the frequency of the frequency-converting radio frequency signal that can be generated without the sensing element 136 connected is determined. The magnitude of the sensing quantity can be indirectly obtained by combining the magnitude of the frequency shift of the frequency-converting radio frequency signal with the relationship between the previously calibrated sensing quantity and the frequency shift of the frequency-converting radio frequency signal.

[0130] For example, when using the frequency converter circuit of Scheme 1, such as Figure 9 As shown, the sensing element 136 is disposed at a position electrically connected to the third modulation port of the modulation element 131. Specifically, the sensing element 136 is disposed on the bypass of the signal transmission path electrically connected to the third modulation port of the modulation element 131 and the switchable narrowband filter array 133.

[0131] For example, when using the frequency converter circuit of Scheme 2, such as Figure 10 As shown, the sensing element 136 is disposed on the bypass of the signal transmission path electrically connected between the broadband filter 132 and the switchable narrowband filter array 133.

[0132] Figure 11 A wireless tag circuit 100 according to one embodiment is provided. Based on any of the aforementioned frequency conversion circuits, it further includes an antenna unit 135. The antenna unit 135 is electrically connected to the first port P1 of the modulation element 131. Depending on the situation, the antenna unit 135 can be electrically connected to the control unit 134.

[0133] When the antenna unit 135 is electrically connected to the control unit 134, the control unit 134 provides the necessary power for its operation through the electromagnetic radiation such as radio frequency or microwave received by the antenna unit 135. In this case, the antenna unit 135 can be any antenna capable of achieving high-efficiency inter-frequency communication, and its specific form can be determined as needed. For example, the antenna unit 135 may include a first antenna and a second antenna that are independent of each other, wherein the first antenna is electrically connected to the first port P1 of the modulation element 131, and the second antenna is electrically connected to the control unit 134; or, the antenna unit 135 may include a first antenna and a duplexer or power divider, wherein the first antenna is electrically connected to the first port P1 of the modulation element 131 and the control unit 134 after passing through the duplexer or power divider.

[0134] When the antenna unit 135 is not electrically connected to the control unit 134, the control unit 134 can convert other forms of energy into electrical energy required for its operation. These other forms of energy include, but are not limited to, the following: solar energy, thermal energy, mechanical energy, biological energy, and electrostatic energy. Solar energy is converted into electrical energy through the photovoltaic effect; thermal energy is typically based on the Seebeck effect, utilizing the temperature difference between object surfaces to generate voltage; mechanical energy includes vibrational energy and kinetic energy, which is typically converted into electrical energy through piezoelectric materials or electromagnetic induction; biological energy is typically generated by the activities of living organisms, such as body temperature, movement, or chemical energy; and electrostatic energy is typically generated through triboelectric charging or the accumulation of charge from environmental static electricity.

[0135] It should be noted that tags can be categorized into passive tags, semi-active tags, and active tags based on their power supply method. Passive tags obtain energy by receiving radio frequency signals transmitted by a reader, thus providing power for a short period to exchange information with the reader. Semi-active tags have a power source (such as a battery), but this power source only supplies power to the tag's internal circuitry when the tag is in a dormant state and activates the tag when it is within the reader's communication range. The energy source for subsequent processing after the tag enters the working state is similar to that of passive tags. Active tags are powered by a power source (such as a battery). This application does not limit the power supply method of the tags.

[0136] In principle, the downlink radio frequency signal can be any suitable frequency, including unlicensed bands open to industrial, scientific, and medical institutions, as well as licensed wireless communication bands, such as 5G NR communication bands. Examples include, but are not limited to, 125kHz, 13.56MHz, 433MHz, 800MHz, 900MHz, 950MHz, 2.4GHz, or 5.8GHz, without specific limitations.

[0137] This solution also provides a wireless tag device 300, which includes a housing and a wireless frequency conversion circuit 100 disclosed in any of the foregoing embodiments. All or part of the wireless frequency conversion circuit is housed within the housing, which protects the circuit and improves its mechanical performance, environmental performance, and service life.

[0138] In some embodiments, the wireless frequency conversion circuit 100 is entirely disposed on the package housing, and the package housing is made of a wave-transparent material at least at the position corresponding to the antenna element 135.

[0139] In some implementations, the antenna unit 135 of the wireless frequency conversion circuit 100 is located outside the enclosure, while other modules are located inside the enclosure. The enclosure is provided with a communication interface that is electrically connected to the antenna unit 135.

[0140] Please refer to Figure 11 The general workflow of the wireless tag circuit 100 or the wireless tag device 300 is as follows:

[0141] Receive downlink radio frequency signals;

[0142] Control unit 134 generates configuration signals;

[0143] The switchable narrowband filter array 132 responds to a configuration signal to anchor the target narrowband filter;

[0144] Send uplink frequency conversion signal.

[0145] The configuration signal generated by the control unit 134 can be divided into two cases: one is to generate the configuration signal based on the preset configuration parameters. It can be understood that the preset configuration parameters can be pre-configured at the factory and stored in the frequency converter circuit; the other is to generate the configuration signal based on the configuration command in the downlink radio frequency signal.

[0146] In some embodiments, the control unit 134 listens to the configuration instructions of the downlink radio frequency signal. When the configuration instructions are the same as the preset configuration parameters, the control unit 134 generates a configuration signal based on the preset configuration parameters. When the configuration instructions are different from the preset configuration parameters, the control unit 134 generates a configuration signal based on the configuration instruction parameters.

[0147] This solution also provides a wireless tag system, such as Figure 12 As shown, it includes a reader 200 and several wireless tag devices 300 disclosed in any of the foregoing embodiments;

[0148] The reader 200 is used to send downlink radio frequency signals to the wireless tag device 300 and to receive uplink frequency conversion signals returned by the wireless tag device 300 that meet preset communication rules, wherein the carrier frequencies of the downlink radio frequency signals and the uplink frequency conversion signals are different.

[0149] For example, the aforementioned preset communication rules are specifically as follows:

[0150] The wireless tag devices 300 within the communication coverage area of ​​the reader 200 are divided into k groups, corresponding to time slots 1 to k respectively; where k is an integer greater than or equal to 1. When k is greater than 1, the number of wireless tag devices 300 in the k groups can be the same or different; for example, the number of wireless tag devices 300 in the first to the kth groups is m; or, the number of wireless tag devices 300 in the first to the (k-1)th groups is m, and the number of wireless tag devices 300 in the kth group is less than m.

[0151] In a certain time slot, a number of wireless tag devices 300, not exceeding m, transmit uplink frequency conversion signals of different frequencies back to the reader 200. The other wireless tag devices 300 within the communication range of the reader 200 do not transmit frequency conversion signals.

[0152] This solution also provides a wireless communication method that uses the aforementioned wireless tag system, the main steps of which are as follows:

[0153] S1, Reader 200 sends downlink radio frequency signal;

[0154] S2, in a certain time slot, a number of wireless tag devices 300, not exceeding m, receive downlink radio frequency signals and return uplink frequency conversion signals with different frequencies to the reader 200. Other wireless tag devices 300 within the communication range of the reader 200 do not send uplink frequency conversion signals. The carrier frequencies of the downlink radio frequency signals and the uplink frequency conversion signals are different.

[0155] S3, the reader 200 receives and analyzes each frequency conversion signal to obtain the corresponding frequency conversion information.

[0156] In step S1, the downlink radio frequency signal sent by the reader 200 is used to provide radio frequency power to the wireless tag device 300 within a specific communication range, thereby waking up the wireless tag device 300 to work.

[0157] In step S2, several wireless tag devices 300 that conform to preset communication rules receive downlink radio frequency signals and return uplink frequency conversion signals with different frequencies under the preset communication rules.

[0158] The preset communication rules can be any suitable rules. For example, several wireless tag devices 300 within the communication coverage area of ​​the reader 200 are divided into k groups, corresponding to 1 to k time slots respectively; where k is an integer greater than or equal to 1. When k is greater than 1, the number of wireless tag devices 300 in the k groups can be the same or different; for example, the number of wireless tag devices 300 in groups 1 to k is m; or, the number of wireless tag devices 300 in groups 1 to k-1 is m, and the number of wireless tag devices 300 in group k is less than m. Each group communicates in turn according to time. In a certain time slot, only the group that has been turned to is allowed to be in a working state and to receive radio frequency energy from the reader 200, thus being able to return uplink frequency-converted signals of different frequencies to the reader 200. Other groups that have not been turned to are in a non-working state and cannot receive or respond to radio frequency energy from the reader 200, thus being unable to send uplink frequency-converted signals. Here, m is the maximum number of sub-bands that the reader 200 can process at the same time.

[0159] In step S3, the reader 200 receives a number of frequency conversion signals not exceeding m. By analyzing each frequency conversion signal, the corresponding frequency conversion information can be obtained.

[0160] Although the invention has been described herein with reference to illustrative embodiments, it should be understood that many other modifications and implementations can be devised by those skilled in the art, which will fall within the scope and spirit of the principles disclosed herein. More specifically, various variations and modifications can be made to the components and / or layout of the subject matter combination within the scope of this disclosure. Besides variations and modifications to the components and / or layout, other uses will be apparent to those skilled in the art.

Claims

1. A frequency converter circuit, characterized in that, It includes a modulation element, a switchable narrowband filter array, a wideband filter, and a control unit; the modulation element is electrically connected to both the switchable narrowband filter array and the wideband filter; the control unit is electrically connected to the switchable narrowband filter array. The control unit is configured to generate a configuration signal; The switchable narrowband filter array includes M narrowband filters, each with a different second resonant frequency; where M is an integer not less than 2. The switchable narrowband filter array is configured to select and anchor a target narrowband filter from the M narrowband filters in response to the configuration signal, wherein the operating bandwidth of the wideband filter covers the operating bandwidth of each narrowband filter.

2. The frequency conversion circuit as described in claim 1, characterized in that, The frequency conversion circuit includes one of the following solutions: Option 1: The modulation element includes a first modulation port, a second modulation port, and a third modulation port, wherein the first modulation port is electrically connected to the antenna element, the second modulation port is electrically connected to the broadband filter, the third modulation port is electrically connected to the switchable narrowband filter array, and the control unit is electrically connected to the switchable narrowband filter array. Option 2: Based on the first scheme, the switchable resonant network is also electrically connected to the broadband filter.

3. A frequency conversion circuit as described in claim 1 or 2, characterized in that, The switchable resonant network further includes an M-select-one sub-unit; wherein... In Option 1, any of the following settings can be used: The first port of each narrowband filter is electrically connected to the third modulation port, and the second port of each narrowband filter is electrically connected to the M-select subunit; the broadband filter is electrically connected to the second modulation port. Alternatively, the M-select subunit is electrically connected to the third modulation port, and each narrowband filter is electrically connected to the M-select subunit; the broadband filter is electrically connected to the second modulation port. In Option 2, any of the following settings can be used: The first port of each narrowband filter is electrically connected to the third modulation port, and the second port of each narrowband filter is electrically connected to the M-select subunit; the first port of the broadband filter is electrically connected to the second modulation port, and the second port of the broadband filter is electrically connected to the second port of each narrowband filter. Alternatively, the M-select subunit is electrically connected to the third modulation port, and the first port of each narrowband filter is electrically connected to the M-select subunit; the first port of the wideband filter is electrically connected to the second modulation port, and the second port of the wideband filter is electrically connected to the second port of each narrowband filter.

4. A frequency converter circuit as described in claim 1 or 2, characterized in that, The narrowband filter adopts one of the following: LC parallel resonant circuit, LC series resonant circuit, and passive piezoelectric resonator; The broadband filter employs one of the following: LC parallel resonant circuit, LC series resonant circuit, RF open circuit, and RF short circuit.

5. A frequency converter circuit as described in claim 4, characterized in that, The passive piezoelectric resonator is one of the following: crystal resonator, ceramic resonator, surface acoustic wave piezoelectric resonator, or MEMS piezoelectric resonator.

6. A frequency converter circuit as described in claim 1 or 2, characterized in that, The modulation element is one of a transistor, bipolar transistor, unipolar transistor, field-effect transistor, junction field-effect transistor, metal-oxide-semiconductor field-effect transistor, two-dimensional electron gas transistor, or high electron mobility transistor.

7. A frequency converter circuit as described in claim 1 or 2, characterized in that, When the modulation element is a bipolar transistor, any of the following configurations are adopted: the first modulation port, the second modulation port, and the third modulation port are respectively the collector, the emitter, and the base, or respectively the emitter, the collector, and the base, or respectively respectively the base, the emitter, and the collector; When the modulation element is a unipolar transistor, any of the following configurations are adopted: the first modulation port, the second modulation port, and the third modulation port are respectively the drain, the source, and the gate, or respectively the source, the drain, and the gate, or respectively the gate, the source, and the drain.

8. A frequency converter circuit as described in claim 1 or 2, characterized in that, The frequency conversion signal is drawn from the first modulation port, or simultaneously from the first modulation port and the second modulation port, or simultaneously from the second modulation port and the third modulation port, or simultaneously from the first modulation port and the third modulation port, or simultaneously from all three modulation ports.

9. A frequency converter circuit as described in claim 2, characterized in that, It also includes sensing elements; In Scheme 1, the sensing element adopts any of the following configuration methods: Electrically connected to the first modulation port; Electrically connected to the second modulation port; Electrically connected to the third modulation port; In Scheme 2, the sensing element adopts any of the following configuration methods: Electrically connected to the first modulation port; Electrically connected to the second modulation port; Electrically connected to the third modulation port; It is positioned as a bypass on the electrical signal transmission path between the switchable narrowband filter array and the wideband filter.

10. A communication method, characterized in that, The method is applied to the frequency converter circuit as described in any one of claims 1-9, and the method includes the following steps: Input downlink radio frequency signal; The control unit generates configuration signals; A switchable narrowband filter array responds to the configuration signal to anchor the target narrowband filter; Output uplink frequency conversion signal.

11. A wireless tag circuit, characterized in that, Includes an antenna unit and a frequency conversion circuit as described in any one of claims 1-9, wherein the antenna unit is electrically connected to a first modulation port of a modulation element; The antenna unit is configured to receive downlink radio frequency signals and transmit uplink frequency conversion signals.

12. A wireless tag device, characterized in that, It includes a housing and a frequency conversion circuit as described in any one of claims 1-9 or a wireless tag circuit as described in claim 11, wherein all or part of the frequency conversion circuit or wireless tag circuit is disposed in the housing.

13. A wireless tag system, characterized in that, Includes a reader and several wireless tag devices as described in claim 12; The reader is used to send downlink radio frequency signals to the wireless tag device and to receive uplink frequency conversion signals returned by the wireless tag device that meet preset communication rules.

14. A wireless communication method, characterized in that, The method is applied to the wireless tag circuit as described in claim 11 or the wireless tag device as described in claim 12, and the method includes the following steps: The antenna unit receives downlink radio frequency signals; The control unit generates configuration signals; A switchable narrowband filter array responds to the configuration signal to anchor the target narrowband filter; The antenna unit transmits uplink frequency conversion signals.

15. A wireless communication method, characterized in that, The method is applied to a reader and includes the following steps: Send downlink radio frequency signals; Receive the uplink frequency conversion signal sent by the wireless tag circuit as described in claim 11 or the wireless tag device as described in claim 12; The uplink frequency conversion signal is analyzed to obtain frequency conversion information.

16. A wireless communication method, characterized in that, The method is applied to the wireless tag system as described in claim 13, and the method includes the following steps: The reader sends downlink radio frequency signals; In a certain time slot, a number of wireless tag devices, not exceeding m, receive downlink radio frequency signals and send uplink frequency conversion signals to the reader. Other wireless tag devices within the reader's communication range do not send uplink frequency conversion signals. The carrier frequency of the uplink frequency conversion signal is different from that of the downlink radio frequency signal. Wherein, m is the maximum number of sub-bands that the reader can process at the same time. The reader receives and parses each uplink frequency conversion signal to obtain the corresponding frequency conversion information.

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