Oscillator unit for dielectric heating-measurement of loss of dielectric material

Abstract

The present invention relates to an aerosol-generating device, and in particular to an aerosol-generating device for dielectrically heating an aerosol-forming substrate of an aerosol-forming article. The aerosol-generating device includes a power source; and an oscillation circuit, the oscillation circuit comprising: a switching unit; and a resonant oscillation feedback circuit connected between the input and the output of the switching unit, the resonant oscillation feedback circuit comprising a dielectric heating element arranged for dielectrically heating the substrate. In operation, an electrical parameter associated with a capacitance of the dielectric heating element is measured to determine a property of the substrate.

Description

Oscillator unit for dielectric heating - measuring dielectric material loss

[0001] This invention relates to an aerosol generating apparatus, and more particularly to an aerosol generating apparatus configured to heat an aerosol forming matrix by dielectric heating. This disclosure also relates to a system including the aforementioned aerosol generating apparatus. Furthermore, this disclosure relates to a method for dielectrically heating an aerosol forming matrix of an aerosol forming article using the aerosol generating apparatus, and to a method for calibrating the aerosol generating apparatus. Background Technology

[0002] Known electrically operated aerosol generation systems typically heat the aerosol forming matrix by one or more of the following methods: conducting heat from a heating element to the aerosol forming matrix, radiating heat from a heating element to the aerosol forming matrix, or drawing heated air through the aerosol forming matrix. Most commonly, heating is achieved by passing an electric current through a resistive heating element, generating Joule heating on the heating element. Induction heating systems have also been proposed, in which Joule heating occurs due to eddy currents induced in the sensor heating element.

[0003] One problem with these heating mechanisms is that they produce uneven heating of the aerosol-forming matrix. The portion of the aerosol-forming matrix closest to the heating element is heated faster or to a higher temperature than the portion farther away from the heating element.

[0004] Systems for dielectric heating of aerosol-forming matrices have been proposed, which advantageously provide uniform heating of the aerosol-forming matrix. However, known dielectric heating systems are less efficient than induction heating systems and require complex circuitry to achieve the necessary voltages and frequencies for dielectric heating of the aerosol-forming matrix.

[0005] The goal is to provide a system that can more efficiently heat aerosols to form a matrix using a dielectric method, while still being achievable in a compact or handheld system. Summary of the Invention

[0006] According to a first aspect, an aerosol generating apparatus is provided for dielectrically heating an aerosol-forming matrix of an aerosol-forming article. The aerosol generating apparatus includes a power supply and an oscillation circuit. The oscillation circuit includes: a switching unit; and a resonant oscillation feedback circuit connected between the input and output of the switching unit, the resonant oscillation feedback circuit including a dielectric heating element arranged for dielectrically heating the matrix, wherein, in operation, electrical parameters associated with the capacitance of the dielectric heating element are measured to determine the properties of the matrix.

[0007] An oscillating circuit allows for more efficient dielectric heating by maximizing losses in the dielectric heating element, since the dielectric heating element is a component of the resonant feedback loop of the oscillating circuit, in order to achieve a relatively high peak AC voltage across the dielectric heating element compared to the voltage supplied by the power source. Determining the properties of the matrix allows for more efficient heating because operation can be tailored to the specific conditions. Heating of the aerosol-forming matrix may cause a change in the resonant frequency due to a decrease in the relative permittivity of the matrix and therefore the capacitance of the dielectric heating element, since the dielectric heating element is part of an oscillating circuit (particularly its feedback loop) that self-oscillates at the resonant frequency of the oscillating circuit. These changes in capacitance and resonant frequency can indicate matrix depletion.

[0008] The dielectric heating element can be removably received as part of the aerosol forming article, is disposable, or is integrated into the resonant oscillation feedback circuit of the aerosol generating device.

[0009] Electrical parameters can be values ​​indicating the relative permittivity of the material forming the matrix, and the properties of the matrix determined therein include matrix attenuation.

[0010] The aerosol generating device may also include a probe or antenna for measuring the oscillation frequency of the oscillating circuit.

[0011] The probe or antenna can measure the electric field at the aerosol-forming matrix, and the controller associated with the probe or antenna can be operated to derive parameters associated with the oscillation frequency of the oscillating circuit from the detected electric field.

[0012] The probe or antenna may include a transverse electromagnetic (TEM) transmission line, a microstrip, an inductor, or an antenna.

[0013] The aerosol generating apparatus may also include a power sensing system for detecting the power consumption value drawn from the power source, wherein the power consumption value can be used as an electrical parameter associated with the capacitance of the dielectric heating element.

[0014] The detected power consumption value can indicate the resonant frequency of the oscillating circuit, because changes in the resonant frequency are proportional to the power loss of the dielectric heating element. This relationship allows the matrix loss to be derived based on the power consumption drawn from the power source, rather than from a frequency measurement device. Using a power sensing system instead of a frequency measurement device like an antenna or probe enables the creation of compact products.

[0015] Power consumption values ​​can indicate the current drawn from the power source, especially the DC power current.

[0016] Since the DC power supply current fed to the oscillator circuit can likely be variable, the value makes it possible to measure or obtain an understanding of the matrix depletion.

[0017] A power sensing system may include a shunt for deriving power supply current.

[0018] A shunt can be connected between the switching unit and the power supply.

[0019] The oscillation frequency of the oscillating circuit is not obtained from the current and / or voltage values ​​detected in the circuit that forms the oscillating circuit or the resonant oscillation feedback circuit.

[0020] The feeding of the dielectric heating element can be accomplished by self-excited oscillation at a very high frequency under resonance, which may not be obtainable by time-based current / voltage analysis.

[0021] The probe or antenna may include a resonant cavity.

[0022] The resonant cavity may have a resonant frequency greater than the operating range of the oscillation frequency of the oscillation circuit, and may include impurities or mechanical defects to have a broadened frequency response, such that the operating range of the oscillation frequency of the oscillation circuit is covered by the broadened frequency response.

[0023] The resonant cavity may include a quarter-wavelength coaxial cavity resonator, preferably a quarter-wavelength coaxial cavity resonator with an inner conductor, wherein the inner conductor may be an insulator doped with impurities.

[0024] The resonant cavity can have a resonant frequency between 8 GHz and 12 GHz, preferably about 10 GHz.

[0025] The resonant cavity can have a quarter wavelength between 6.3 mm and 9.4 mm, preferably about 7.5 mm.

[0026] The switching unit may include a frequency measuring device for measuring the switching frequency of the transistors in the switching unit.

[0027] The aerosol generating apparatus may also include a signal processing unit for converting the output provided by the resonant cavity into a signal that can be received by a controller associated with the resonant cavity.

[0028] The signal processing unit may include: a rectifier connected to the resonant cavity to generate a DC signal from the output of the cavity resonator; an impedance element, preferably a resistor, on which the DC signal is applied; and a voltage sensor for measuring the voltage fed to the impedance element of the controller.

[0029] The resonant cavity can be removably or integrated into the region that is penetrated by the electric field of the dielectric heating element during operation of the dielectric heating element.

[0030] The area can be the surrounding area of ​​the dielectric heating element.

[0031] The region may be a heated cavity for receiving the aerosol-forming matrix, wherein a resonant cavity may be placed therein to avoid obstructing the aerosol-forming matrix.

[0032] The oscillation frequency of the oscillation circuit can be in the range of 10MHz to 100GHz, preferably between 100MHz and 1.5GHz, and particularly between 200MHz and 900MHz.

[0033] These frequency ranges allow for the use of cheaper components and simpler circuit designs. Furthermore, the electric field strength can be reduced within these frequency ranges, thereby lowering the risk of electrical breakdown and keeping the substrate stable.

[0034] The aerosol generating device may include a flexible low-dielectric carrier film, and at least a portion of the oscillation circuit may be formed on the flexible low-dielectric carrier film.

[0035] The probe or antenna can be formed on or within a flexible low-dielectric carrier film.

[0036] The aerosol generating apparatus may also include a data processor configured to determine the level of attenuation of the matrix properties based on the relationship with the oscillation frequency of the oscillation circuit.

[0037] It is advantageous to obtain the matrix depletion level using the oscillation frequency of the oscillating circuit (i.e., the self-oscillation frequency of the oscillating circuit) in the relationship, because there are several possible measurement methods that indicate the frequency and therefore the matrix depletion. In other words, the relationship may or may not directly consider the frequency. In this regard, the matrix depletion can be derived from the self-oscillation frequency of the oscillating circuit, measured by, for example, an antenna, or, in an alternative embodiment, can be determined by having information about the power consumption (voltage / current) of the oscillating circuit, which indicates and depends on the self-oscillation frequency of the oscillating circuit.

[0038] There are patent applications relating to measuring the attenuation level of a liquid cylinder in an electron vapor space (in which two electrode plates are stimulated at a certain frequency) to determine the volume and subsequently the liquid level. One of these patents is WO2018114849A1.

[0039] In contrast, in this application, the attenuation measurement and dielectric heating principle can be integrated because the electrodes (especially electrode plates) are used for heating and are simultaneously a functional part of the resonant circuit that affects the resonant frequency. A separate capacitive level measurement may not be necessary.

[0040] In other words, the electrodes can be used for both dissipation measurement (e.g., via power consumption measurement) and dielectric heating. Dissipation measurement can be performed simultaneously with dielectric heating or with a time delay.

[0041] Pre-storing relationships in the data processor enables more efficient operations because the relationships can undergo calibration at the factory level.

[0042] This relationship can correlate an increase in frequency with an increase in the level of attenuation.

[0043] An increase in the level of attenuation or frequency can indicate a decrease in the relative permittivity of the matrix and thus a decrease in the capacity of the dielectric heating element, due to the reduced share of aerosol-forming material in the aerosol-forming matrix during heating operations compared to the share of carrier material such as tobacco-based or cellulose materials.

[0044] The frequency of change from complete matrix consumption to the maximum depletion level is between 3% and 25%, preferably between 5% and 20%, and particularly between 7% and 15%.

[0045] These frequency ranges allow for improved determination of attenuation because the variation from an intact matrix to an empty matrix is ​​relatively large and can be further increased by using liquid fillers or aerosolizers or materials (e.g., water, PPG, glycerol) with significantly higher dielectric constants than tobacco materials in the matrix.

[0046] The minimum loss level can indicate the initial state of the aerosol-forming matrix, and the maximum loss level can indicate the state in which at least a portion of the aerosol-forming material present in the initial state (preferably between 50% and 100%, particularly between 80% and 95%) can be evaporated or aerosolized.

[0047] The relationship may include a mapping function MF, which maps parameters associated with the oscillation frequency of the oscillation circuit to a predefined or predetermined dissipation level.

[0048] The mapping function MF may include a lookup table, a correspondence table, an algorithm, a regression mapping, or a trained artificial intelligence network.

[0049] The parameters can indicate the self-resonant frequency of the oscillation circuit.

[0050] The parameters may include power consumption values.

[0051] This relationship allows for the depletion of the substrate to be derived from the power consumption drawn from the power source, rather than from a frequency measurement device. Using a power sensing system instead of a frequency measurement device like an antenna or probe enables the creation of compact products.

[0052] The power consumption value may include one or more of the DC power supply current and the DC power supply voltage.

[0053] The DC power supply voltage can be controlled to a fixed value, and the parameter indicates the DC power supply current.

[0054] In this respect, although the DC voltage level provided by the power supply can be fixed, the DC voltage level provided by the output of the DC-DC converter can be variable.

[0055] The mapping function can correlate an increase in power consumption with an increase in the level of power reduction.

[0056] The aerosol generating device may also include a memory, wherein the mapping function may be pre-stored in the memory, and the mapping function may indicate the correlation between different power consumption modes, such as DC current and / or DC voltage obtained from the power supply of the calibration device or the aerosol generating device, and the measured oscillation frequency of the oscillation circuit.

[0057] The parameters may also include the heating duration of the current heating process.

[0058] The heating duration may include one or more of the time from the start of the current heating process or the number of suctions performed during the current heating process.

[0059] The parameters may also include heating temperature; and / or humidity level.

[0060] The heating temperature may include at least one of the temperature of the air in the cavity used to receive the aerosol-forming matrix and the matrix temperature.

[0061] The data processor can be configured to output a control signal to enable heating operation when the aerosol-forming matrix depletion level is below a threshold, or to disable heating operation when the aerosol-forming matrix depletion level exceeds a threshold.

[0062] The threshold can indicate that the matrix is ​​empty, and disabling heating operation can include turning off or slowing down the heating operation when the depletion level of the aerosol-forming matrix exceeds the threshold.

[0063] The control signal can be used for matrix identification.

[0064] The dielectric heating element can be a load capacitor C. L .

[0065] The load capacitor C L It may include electrodes for receiving the substrate therebetween, such as electrode plates E1, E2.

[0066] The resonant oscillation feedback circuit can be a self-resonant oscillation feedback circuit.

[0067] The resonant oscillation feedback circuit may include at least a first inductor L1, and the first inductor L1 and the load capacitor C, which serves as a dielectric heating element, are connected. L Connected in series.

[0068] The resonant oscillation feedback circuit may include a first inductor L1 and a second inductor L2, wherein inductors L1 and L2 may be connected to a load capacitor C. L Connected in series.

[0069] The first inductor L1 and the second inductor L2 can be distributed relative to each other, such that a mutual inductance 2M can be generated between them.

[0070] The mutual inductance 2M can be in the range of 7nH to 30nH, more preferably between 10nH and 20nH.

[0071] Each of the at least two inductors may include fewer than five windings, preferably one or two windings.

[0072] The aerosol generating apparatus may further include a controller for controlling an oscillating circuit to induce heating of the matrix by changing parameters or configuration of the aerosol generating apparatus.

[0073] Changes to the parameters or configuration of the aerosol generating device may include enabling or disabling the switching unit by establishing or disconnecting the connection between the power supply and the switching unit, respectively.

[0074] Changes to the parameters or configuration of the aerosol generating device may not include any control actions used to change the switching frequency of the transistors in the switching unit.

[0075] Changes to the parameters or configuration of the aerosol generating device may include enabling or disabling the switching unit by enabling or disabling the resonant oscillation feedback circuit, respectively.

[0076] Changes to the parameters or configuration of the aerosol generating device may include the controller controlling the DC power supply voltage provided by the power source.

[0077] Changes to the parameters or configuration of the aerosol generating device can be based on signals from the data processor.

[0078] The parameters or configuration of the aerosol generating device can be changed so that the oscillation circuit can be activated when the depletion level is below a threshold.

[0079] The controller can be operable to control the temperature of the aerosol-forming matrix by first applying a preheating stage to reach a temperature higher than the aerosolization temperature of the aerosol-forming material and then performing a suction heating stage in which the temperature is maintained constant.

[0080] The controller is operable to control the temperature of the heating element within a temperature range of 150° to 400°, preferably 180° to 300°, and particularly 220° to 240° during the suction heating phase.

[0081] The resonant oscillation feedback circuit may include at least a load capacitor C connected to the dielectric heating element. L The first inductor L1, wherein the resonant oscillation feedback circuit can be used during heating operation by at least the first inductor L1 and the load capacitor C L The formed LC circuit resonates at its self-resonant frequency.

[0082] The aerosol generating apparatus may also include an indicator for outputting to the user a status related to the level of matrix depletion or filling level.

[0083] The indicating device may include one or more of a display, a vibration feedback device, and an acoustic signaling device.

[0084] The state can indicate that the substrate is considered empty.

[0085] The oscillation circuit may also include a delay line D. L (Sometimes referred to as a delay element), delay line D L It branches off from the path of the resonant oscillation feedback circuit.

[0086] A delay line oscillator uses a delay line D. L Or, in the form of an electronic oscillator where a delay element serves as its primary timing element. A delay line oscillator can be configured to operate via a delay line D... L Alternatively, the output of the delay element can be inverted and appropriately amplified before being fed back to the delay line D. L Oscillations may occur due to the input of a delay element.

[0087] Delay elements can be implemented using physical delay lines, such as LC networks or transmission lines. In some instances, capacitors and inductors can be distributed along the length of the delay element. In some instances, delay elements comprise cascades of logic gates used to generate gate delays. Oscillating circuits using physical delay elements can be much more accurate in timing. It is also easier to make such oscillating circuits oscillate in the desired mode.

[0088] The resonant oscillation feedback circuit may also include a second capacitor C2, which is connected between the resonant oscillation feedback circuit and ground, so that the second capacitor C2 can provide a 90° phase shift of the feedback voltage.

[0089] According to a second aspect, a system is provided, the system comprising: an aerosol generating article including an aerosol forming matrix; and an aerosol generating apparatus for dielectrically heating the aerosol forming matrix, preferably an aerosol generating apparatus according to the first aspect.

[0090] Aerosol-generated products can be in the form of rods or plates.

[0091] Aerosol-forming matrices can contain solid materials.

[0092] Aerosol forming matrix can include carrier materials and aerosol forming materials.

[0093] The carrier material can have a relative permittivity that is lower than that of the aerosol forming material.

[0094] The relative permittivity of the carrier material can be from one-third to one-thirtieth of the relative permittivity of the aerosol forming material, preferably from one-fifth to one-fifteenth.

[0095] The carrier material may include tobacco, tobacco substitutes, or cellulose-based materials.

[0096] The carrier material can include solid materials.

[0097] The carrier material may include tobacco-based materials.

[0098] Carrier materials may include alkaloids, such as nicotine.

[0099] Carrier materials may include flavoring materials.

[0100] Tobacco-based materials may have a relative permittivity between 1 and 8, preferably between 2 and 4, and particularly between 2.3 and 2.7.

[0101] Aerosol forming materials can include liquid or gel-like aerosol forming materials.

[0102] Aerosol forming materials may include a mixture of polypropylene glycol (PPG) and glycerin.

[0103] The aerosol matrix can include water.

[0104] Aerosol forming materials can have a relative permittivity between 10 and 60, preferably 14 to 43, and particularly 28 to 32.

[0105] The aerosolization temperature of the aerosol forming material can be lower than that of the carrier material.

[0106] According to a third aspect, a method is provided for dielectrically heating an aerosol-forming matrix of an aerosol-forming article using an aerosol generating apparatus. The method includes the steps of: supplying power from a power source to an oscillating circuit of the aerosol generating apparatus, the oscillating circuit including: a switching unit; a resonant oscillation feedback circuit connected between the input and output of the switching unit, the resonant oscillation feedback circuit including a dielectric heating element arranged for heating the matrix; and measuring electrical parameters associated with the capacitance of the dielectric heating element to determine the properties of the matrix.

[0107] The method may further include determining the properties of the matrix, wherein the determination may include mapping the measured electrical parameters to the properties of the matrix by means of a mapping function preferably pre-stored on the aerosol generating device.

[0108] The method may further include performing actions on the aerosol generating apparatus based on the determined properties of the matrix.

[0109] The electrical parameters may include the power consumption value drawn from the power source, preferably DC power current, and the determined properties of the substrate may include the substrate's depletion level.

[0110] When the depletion level exceeds a threshold, the action may include at least one of shutting off the heating operation, slowing down the heating operation, and instructing the user that the substrate is considered empty.

[0111] The method steps can be performed by an aerosol generating apparatus according to the first aspect.

[0112] According to a fourth aspect, a method for calibrating an aerosol generating apparatus is provided. The method includes the steps of: providing power from a power source to an oscillating circuit of the aerosol generating apparatus, the oscillating circuit including: a switching unit; and a resonant oscillation feedback circuit including two opposing electrodes E1, E2 for heating an aerosol forming matrix, wherein the matrix is ​​located between the two opposing electrodes; measuring the frequency of the electric field between the electrodes; relating the measured frequency to the provided power; and storing the obtained relationship in a mapping function of the aerosol generating apparatus.

[0113] A resonant oscillation feedback circuit can be connected between the input and output of a switching unit.

[0114] The procedure can be performed by the aerosol generating device or by a separate calibration device.

[0115] The aerosol generating apparatus may be the aerosol generating apparatus according to the first aspect.

[0116] According to the fifth aspect, a resonant cavity is provided for measuring the oscillation frequency of an oscillation circuit of an aerosol generating device.

[0117] The aerosol generating apparatus of the fifth aspect can be the aerosol generating apparatus according to the first aspect.

[0118] The resonant cavity can be used to measure the frequency of the electric field between the electrodes according to the calibration method in the fourth aspect.

[0119] The resonant cavity may have a resonant frequency greater than the operating range of the oscillation frequency of the oscillation circuit, and may include impurities or mechanical defects to have a broadened frequency response, such that the operating range of the oscillation frequency of the oscillation circuit is covered by the broadened frequency response.

[0120] The resonant cavity may include a quarter-wavelength coaxial cavity resonator, preferably a quarter-wavelength coaxial cavity resonator with an inner conductor, wherein the inner conductor may be an insulator doped with impurities.

[0121] The resonant cavity can have a resonant frequency between 8 GHz and 12 GHz, preferably about 10 GHz.

[0122] The resonant cavity can have a quarter wavelength between 6.3 mm and 9.4 mm, preferably about 7.5 mm.

[0123] The switching unit may include a frequency measuring device for measuring the switching frequency of the transistors in the switching unit.

[0124] The aerosol generating apparatus may also include a signal processing unit for converting the output provided by the resonant cavity into a signal that can be received by a controller associated with the resonant cavity.

[0125] The signal processing unit may include: a rectifier connected to the resonant cavity to generate a DC signal from the output of the cavity resonator; an impedance element, preferably a resistor, on which the DC signal is applied; and a voltage sensor for measuring the voltage fed to the impedance element of the controller.

[0126] The resonant cavity can be removably or integrated into the region that is penetrated by the electric field of the dielectric heating element during operation of the dielectric heating element.

[0127] The area can be the surrounding area of ​​the dielectric heating element.

[0128] The region may be a heated cavity for receiving the aerosol-forming matrix, wherein a resonant cavity may be placed therein to avoid obstructing the aerosol-forming matrix.

[0129] In this example, the feedback loop can be suspended between the power supply to the oscillating circuit and ground. This means there is no direct connection between the feedback loop and the power supply voltage or ground—for example, at least one electrical component (e.g., a resistor or capacitor) can be present, creating a non-negligible potential difference between the feedback loop and the power supply and ground in the oscillating circuit. This can reduce the effects of noise and grounding, resulting in more predictable operation in the feedback loop.

[0130] As used herein, the term "aerosol generating apparatus" refers to an apparatus that interacts with an article comprising an aerosol forming matrix to generate an aerosol.

[0131] As used herein, the term "aerosol-forming matrix" refers to a matrix capable of releasing volatile compounds that can form aerosols. These volatile compounds can be released by heating the aerosol-forming matrix.

[0132] As used herein, the term "relative permittivity" (also referred to as dielectric constant) refers to the dielectric constant of the material forming the aerosol matrix, expressed as a ratio to the permittivity of vacuum. Mathematically, the relative permittivity is expressed as: εr = ε / ε0. The parameters in this equation are defined as follows: ε is the permittivity of the matrix-forming material; ε0 is the permittivity of vacuum; and εr is the relative permittivity of the matrix-forming material. In particular, the term "relative permittivity" can also be referred to as the real part of the frequency-dependent complex relative permittivity measured at 20°C in an alternating electric field having a very low frequency (VLF) of 1 kHz or less (as defined in International Standard IEC 62631-2-1:2018). It should be understood that only the 1 kHz frequency value is included here for general reference, and other definitions may use different frequencies.

[0133] As used herein, the term "data processor" refers to a component of the controller of an aerosol generating apparatus, or in some embodiments, it may refer to a separate entity.

[0134] As used herein, the term "power sensing system" refers to a measuring device or circuit that enables the detection of one or more of current, voltage, and power values.

[0135] As used herein, the term "electric field strength" refers to the electric field strength across the electrodes, preferably the electrode plates, of a capacitor used for dielectric heating. The electric field strength increases proportionally to the voltage of the alternating voltage applied to the capacitor, particularly the effective voltage (also known as voltage strength), and is inversely proportional to the distance between the electrodes of the capacitor.

[0136] As used in this article, the term "resonant oscillation feedback (loop) circuit" refers to the resonant circuit of the feedback loop of an oscillation circuit.

[0137] As used in this article, the term "power supply" refers to a power supply device.

[0138] As used herein, the term "target heating phase" (also referred to as "maintain heating phase") refers to the "nominal heating operation" during which the consumer is using the device for inhalation. During the target heating phase, the aerosol-forming matrix may preferably be heated according to a heating profile to reach or maintain a target aerosolization temperature for inhalation.

[0139] The invention is defined in the claims. However, a non-exhaustive list of non-limiting examples is provided below. Any one or more features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0140] Example Ex1: An aerosol generating apparatus for dielectrically heating an aerosol forming matrix of an aerosol forming article, the aerosol generating apparatus comprising: a power supply; and an oscillation circuit comprising: a switching unit; and a resonant oscillation feedback circuit comprising a dielectric heating element arranged for dielectrically heating the matrix; wherein, in operation, electrical parameters associated with the capacitance of the dielectric heating element are measured to determine the properties of the matrix.

[0141] Example Ex2: According to the aerosol generating apparatus of Example Ex1, the dielectric heating element is removably received as part of the aerosol forming article, is disposable, or is integrated into the resonant oscillation feedback circuit of the aerosol generating apparatus.

[0142] Example Ex3: An aerosol generating apparatus according to Example Ex1 or Ex2, wherein the electrical parameter is a value indicating the relative permittivity of the material forming the matrix, and wherein the determined properties of the matrix include the attenuation of the matrix.

[0143] Example Ex4: An aerosol generating apparatus according to any of the preceding examples, wherein the aerosol generating apparatus further includes a probe or antenna for measuring the oscillation frequency of the oscillation circuit.

[0144] Example Ex5: An aerosol generating apparatus according to Example Ex4, wherein the probe or antenna measures the electric field at the aerosol forming matrix, and wherein a controller associated with the probe or antenna is operable to derive a parameter associated with the oscillation frequency of the oscillation circuit from the detected electric field.

[0145] Example Ex6: An aerosol generating apparatus according to Example Ex4 or Ex5, wherein the probe or antenna includes a transverse electromagnetic (TEM) transmission line, a microstrip, an inductor, or an antenna.

[0146] Example Ex7: An aerosol generating apparatus according to any of the foregoing examples, wherein the aerosol generating apparatus further includes a power sensing system for detecting a power consumption value drawn from the power source, and wherein the power consumption value is used as the electrical parameter associated with the capacitance of the dielectric heating element.

[0147] Example Ex8: An aerosol generating apparatus according to Example Ex7, wherein the power consumption value indicates the power supply current drawn from the power source, specifically the DC power supply current. Since the DC power supply current fed to the oscillation circuit can likely be variable, this value allows for the measurement or acquisition of information about the matrix depletion.

[0148] Example Ex9: An aerosol generating apparatus according to Example EX7 or Ex8, wherein the power sensing system includes a shunt for deriving the power supply current.

[0149] Example Ex10: An aerosol generating apparatus according to Example Ex9, wherein the shunt is connected between the switching unit and the power supply.

[0150] Example Ex11: An aerosol generating apparatus according to Example Ex4, wherein the probe or antenna includes a resonant cavity.

[0151] Example Ex12: An aerosol generating apparatus according to Example Ex11, wherein the resonant cavity has a resonant frequency greater than the operating range of the oscillation frequency of the oscillation circuit, and includes impurities or mechanical defects to have a broadened frequency response, such that the operating range of the oscillation frequency of the oscillation circuit is covered by the broadened frequency response.

[0152] Example Ex13: An aerosol generating apparatus according to Example Ex11 or Ex12, wherein the resonant cavity comprises a quarter-wavelength coaxial cavity resonator, preferably a quarter-wavelength coaxial cavity resonator having an inner conductor, wherein the inner conductor has an insulator doped with impurities.

[0153] Example Ex14: An aerosol generating apparatus according to any one of Examples Ex11 to Ex13, wherein the resonant cavity has a resonant frequency between 8 GHz and 12 GHz, preferably about 10 GHz.

[0154] Example Ex15: An aerosol generating apparatus according to any one of Examples Ex11 to Ex14, wherein the resonant cavity has a quarter wavelength between 6.3 mm and 9.4 mm, preferably about 7.5 mm.

[0155] Example Ex16: An aerosol generating apparatus according to any of the foregoing examples, wherein the switching unit includes a frequency measuring device for measuring the switching frequency of the transistor of the switching unit.

[0156] Example Ex17: An aerosol generating apparatus according to any of the foregoing examples further includes a signal processing unit for converting the output provided by the resonant cavity into a signal receivable by a controller associated with the resonant cavity.

[0157] Example Ex18: An aerosol generating apparatus according to Example Ex17, wherein the signal processing unit comprises: a rectifier connected to the resonant cavity to generate a DC signal from the output of the cavity resonator, and an impedance element, preferably a resistor, on which the DC signal is applied; and a voltage sensor for measuring the voltage fed to the impedance element of the controller.

[0158] Example Ex19: An aerosol generating apparatus according to any one of Examples Ex11 to Ex15, wherein the resonant cavity is removably or integratedly placed in a region penetrated by the electric field of the dielectric heating element during operation of the dielectric heating element.

[0159] Example Ex20: An aerosol generating apparatus according to Example Ex19, wherein the region is the peripheral region of the dielectric heating element.

[0160] Example Ex21: An aerosol generating apparatus according to Example Ex19, wherein the region is a heating chamber for receiving the aerosol forming matrix, wherein the resonant cavity is placed therein to avoid obstructing the aerosol forming matrix.

[0161] Example Ex22: An aerosol generating apparatus according to any of the foregoing examples, wherein the oscillation frequency of the oscillation circuit is in the range of 10 MHz to 100 GHz, preferably between 100 MHz and 1.5 GHz, and particularly between 200 MHz and 900 MHz.

[0162] Example Ex23: An aerosol generating apparatus according to any of the foregoing examples, wherein the aerosol generating apparatus includes a flexible low-dielectric carrier film, and wherein at least a portion of the oscillating circuit is formed on the flexible low-dielectric carrier film.

[0163] Example Ex24: An aerosol generating apparatus according to Example Ex23, wherein the probe or antenna is formed on or within the flexible low-dielectric carrier film, or the antenna is formed on or within the flexible low-dielectric carrier film.

[0164] Example Ex25: An aerosol generating apparatus according to any one of Examples Ex3 to Ex24 further includes a data processor configured to determine the level of attenuation of the properties of the matrix based on a relationship with the oscillation frequency of the oscillation circuit.

[0165] Example Ex26: An aerosol generating apparatus according to Example Ex25, wherein the relationship associates the increase in frequency with the increase in the attenuation level.

[0166] Example Ex27: An aerosol generating apparatus according to Example Ex25 or Ex26, wherein the increase in the attenuation level or the frequency indicates a decrease in the relative permittivity of the matrix and therefore a decrease in the capacity of the dielectric heating element, due to a reduction in the share of aerosol forming material in the aerosol forming matrix during heating operation compared to the share of a carrier material such as tobacco-based or cellulose material.

[0167] Example Ex28: An aerosol generating apparatus according to any one of Examples Ex25 to Ex27, wherein the frequency change from complete matrix consumption to maximum depletion level is between 3% and 25%, preferably between 5% and 20%, particularly between 7% and 15%.

[0168] Example Ex29: An aerosol generating apparatus according to any one of Examples Ex25 to Ex28, wherein the minimum loss level indicates the initial state of the aerosol forming matrix, and wherein the maximum loss level indicates that at least a portion (preferably between 50% and 100%, particularly between 80% and 95%) of the aerosol forming material in the initial state is evaporated or aerosolized.

[0169] Example Ex30: An aerosol generating apparatus according to any one of Examples Ex25 to Ex29, wherein the relationship includes a mapping function MF that maps parameters associated with the oscillation frequency of the oscillation circuit to a predefined or predetermined attenuation level.

[0170] Example Ex31: An aerosol generating apparatus according to Example Ex30, wherein the mapping function MF includes a lookup table, a correspondence table, an algorithm, a regression mapping, and a trained artificial intelligence network.

[0171] Example Ex32: An aerosol generating apparatus according to Example Ex30 or Ex31, wherein the parameter indicates the self-resonant frequency of the oscillating circuit.

[0172] Example Ex33: An aerosol generating apparatus according to any one of Examples Ex30 to Ex32, wherein the parameters include power consumption values.

[0173] Example Ex34: An aerosol generating apparatus according to Example Ex33, wherein the power consumption value includes one or more of DC power supply current and DC power supply voltage.

[0174] Example Ex35: In the aerosol generating apparatus according to Example Ex33 or Ex34, the DC power supply voltage is controlled to a fixed value, and the parameter indicates the DC power supply current. In this respect, although the DC voltage level provided by the power supply may be fixed, the DC voltage level provided by the output of the DC-DC converter may be variable.

[0175] Example Ex36: An aerosol generating apparatus according to any one of Examples Ex33 to Ex35, wherein the mapping function associates an increase in the power consumption value with an increase in the power reduction level.

[0176] Example Ex37: An aerosol generating apparatus according to any one of Examples Ex33 to Ex36 further includes a memory, wherein a mapping function is pre-stored in the memory, wherein the mapping function indicates the correlation between different power consumption modes, such as DC current and / or DC voltage obtained from a calibration device or a power supply of the aerosol generating apparatus, and the measured oscillation frequency of the oscillation circuit.

[0177] Example Ex38: An aerosol generating apparatus according to any one of Examples Ex33 to Ex37, wherein the parameter further includes the heating duration of the current heating process.

[0178] Example Ex39: An aerosol generating apparatus according to Example Ex38, wherein the heating duration includes one or more of the time from the start of the current heating process or the number of aspirations performed during the current heating process.

[0179] Example Ex40: An aerosol generating apparatus according to any one of Examples Ex33 to Ex39, wherein the parameters further include heating temperature; and / or humidity level.

[0180] Example Ex41: An aerosol generating apparatus according to Example Ex40, wherein the heating temperature includes at least one of the temperature of air in the cavity for receiving the aerosol forming matrix and the matrix temperature.

[0181] Example Ex42: An aerosol generating apparatus according to any one of Examples Ex25 to Ex41, wherein the data processor is configured to output a control signal for enabling heating operation when the depletion level of the aerosol forming matrix is ​​below a threshold, or to disable heating operation when the depletion level of the aerosol forming matrix exceeds a threshold.

[0182] Example Ex43: An aerosol generating apparatus according to Example Ex42, wherein a threshold indicates that the matrix is ​​empty, and wherein disabling heating operation includes turning off or slowing down the heating operation when the depletion level of the aerosol forming matrix exceeds the threshold.

[0183] Example Ex44: An aerosol generating apparatus according to Example Ex42 or Ex43, wherein the control signal is used for matrix identification.

[0184] Example Ex45: An aerosol generating apparatus according to any of the foregoing examples, wherein the dielectric heating element is a load capacitor C. L .

[0185] Example Ex46: An aerosol generating apparatus according to Example Ex45, wherein the load capacitor C L Includes electrodes for receiving the matrix therebetween, such as electrode plates E1, E2.

[0186] Example Ex47: An aerosol generating apparatus according to any of the preceding examples, wherein the resonant oscillation feedback circuit is a self-resonant oscillation feedback circuit.

[0187] Example Ex48: An aerosol generating apparatus according to any of the foregoing examples, wherein the resonant oscillation feedback circuit includes at least a first inductor L1, the first inductor L1 and the load capacitor C serving as the dielectric heating element L Connected in series.

[0188] Example Ex49: An aerosol generating apparatus according to any of the foregoing examples, wherein the resonant oscillation feedback circuit includes a first inductor L1 and a second inductor L2, wherein the inductors L1 and L2 are connected therebetween with respect to the load capacitor C. L Connected in series.

[0189] Example Ex50: An aerosol generating apparatus according to Example Ex49, wherein the first inductor L1 and the second inductor L2 are distributed relative to each other such that a mutual inductance 2M is generated between them.

[0190] Example Ex51: According to the aerosol generating apparatus of Example Ex50, the mutual inductance 2M is in the range of 7nH to 30nH, more preferably 10nH to 20nH.

[0191] Example Ex52: An aerosol generating apparatus according to any one of Examples Ex49 to Ex51, wherein at least two inductors each include fewer than five windings, preferably one or two windings.

[0192] Example Ex53: An aerosol generating apparatus according to any of the foregoing examples further includes a controller for controlling the oscillating circuit to induce heating of the matrix by changing the parameters or configuration of the aerosol generating apparatus.

[0193] Example Ex54: An aerosol generating apparatus according to Example Ex53, wherein changes to the parameters or configuration of the aerosol generating apparatus include enabling or disabling the switching unit by establishing or disconnecting the connection between the power supply and the switching unit, respectively.

[0194] Example Ex55: An aerosol generating apparatus according to Example Ex53 or Ex54, wherein changes to the parameters or configuration of the aerosol generating apparatus do not include any control action to change the switching frequency of the transistors of the switching unit.

[0195] Example Ex56: An aerosol generating apparatus according to any one of Examples Ex53 to Ex55, wherein changing the parameters or configuration of the aerosol generating apparatus includes enabling or disabling the switching unit by enabling or disabling the resonant oscillation feedback circuit, respectively.

[0196] Example Ex57: An aerosol generating apparatus according to any one of Examples Ex53 to Ex56, wherein changes to the parameters or configuration of the aerosol generating apparatus include the controller controlling the DC power supply voltage provided by the power source.

[0197] Example Ex58: An aerosol generating apparatus according to any one of Examples Ex53 to Ex57, wherein changes to the parameters or configuration of the aerosol generating apparatus are based on signals from the data processor.

[0198] Example Ex59: An aerosol generating apparatus according to any one of Examples Ex53 to Ex57, wherein a change in the parameters or configuration of the aerosol generating apparatus is performed such that the oscillation circuit is activated when the attenuation level is below a threshold. Example Ex60: An aerosol generating apparatus according to any one of Examples Ex53 to Ex59, wherein the controller is operable to control the temperature of the aerosol forming matrix by first applying a preheating stage to reach a temperature higher than the aerosolization temperature of the aerosol forming material and then performing a suction heating stage in which the temperature is maintained constant.

[0199] Example Ex61: An aerosol generating apparatus according to any one of Examples Ex43 to Ex60, wherein the controller is operable to control the temperature of the heating element within a temperature range of 150° to 400°, preferably between 180° to 300°, and particularly between 220° to 240° during the suction heating phase.

[0200] Example Ex62: An aerosol generating apparatus according to any of the foregoing examples, wherein the resonant oscillation feedback circuit includes at least a load capacitor C connected to the dielectric heating element. LThe first inductor L1, wherein the resonant oscillation feedback circuit operates during heating by at least the first inductor L1 and the load capacitor C. L The formed LC circuit resonates at its self-resonant frequency.

[0201] Example Ex63: An aerosol generating apparatus according to any one of Examples Ex25 to Ex62 further includes an indicator for outputting to a user a status related to the level of depletion or the level of filling of the matrix.

[0202] Example Ex64: An aerosol generating apparatus according to Example Ex63, wherein the indicating device includes one or more of a display, a vibration feedback device, and an acoustic signaling device.

[0203] Example Ex65: An aerosol generating apparatus according to Example Ex63 or Ex64, wherein the state indicates that the matrix is ​​considered empty.

[0204] Example Ex66: An aerosol generating apparatus according to any of the foregoing examples, wherein the oscillation circuit further includes a delay line D. L The delay line D L It branches off from the path of the resonant oscillation feedback circuit.

[0205] Example Ex67: In the aerosol generating apparatus according to any of the preceding examples, the resonant oscillation feedback circuit further includes a second capacitor C2 connected between the resonant oscillation feedback circuit and ground, such that the second capacitor C2 provides a 90° phase shift in the feedback voltage.

[0206] Example Ex68: A system comprising: an aerosol generating article including an aerosol forming matrix; and an aerosol generating apparatus according to any of the foregoing examples for dielectrically heating the aerosol forming matrix.

[0207] Example Ex69: According to the system of Example Ex68, the aerosol generating article is in the form of a rod or plate.

[0208] Example Ex70: The system according to Example Ex68 or Ex69, wherein the aerosol forming matrix comprises a solid material.

[0209] Example Ex71: A system according to any one of Examples Ex68 to Ex70, wherein the aerosol forming matrix comprises a carrier material and an aerosol forming material.

[0210] Example Ex72: According to the system of Example Ex71, the carrier material has a relative permittivity that is lower than that of the aerosol forming material.

[0211] Example Ex73: According to the system of Example Ex71 or Ex72, the relative permittivity of the carrier material is from one-third to one-thirtieth, preferably from one-fifth to one-fifteenth, of the relative permittivity of the aerosol forming material.

[0212] Example Ex74: A system according to any one of Examples Ex71 to Ex73, wherein the carrier material comprises tobacco, tobacco substitutes or cellulose-based materials.

[0213] Example Ex75: A system according to any one of Examples Ex71 to Ex74, wherein the carrier material comprises a solid material.

[0214] Example Ex76: A system according to any one of Examples Ex71 to Ex75, wherein the carrier material comprises at least one of the following: tobacco-based material; alkaloids, such as nicotine; and flavoring material.

[0215] Example Ex77: The system according to Example Ex74, wherein the tobacco-based material has a relative permittivity between 1 and 8, preferably between 2 and 4, and particularly between 2.3 and 2.7.

[0216] Example Ex78: A system according to any one of Examples Ex68 to Ex77, wherein the aerosol forming material comprises a liquid or gel-like aerosol forming material.

[0217] Example Ex79: A system according to any one of Examples Ex68 to Ex78, wherein the aerosol forming material comprises a mixture between polypropylene glycol (PPG) and glycerin.

[0218] Example Ex80: A system according to any one of Examples Ex68 to Ex79, wherein the aerosol forming matrix comprises water.

[0219] Example Ex81: A system according to any one of Examples Ex68 to Ex80, wherein the aerosol forming material has a relative permittivity between 10 and 60, preferably 14 to 43, particularly 28 to 32.

[0220] Example Ex82: A system according to any one of Examples Ex68 to Ex81, wherein the aerosol forming material has an aerosolization temperature lower than that of the carrier material.

[0221] Example Ex83: A method for dielectrically heating an aerosol-forming matrix of an aerosol-forming article using an aerosol-generating apparatus, the method comprising the steps of: supplying power from a power source to an oscillating circuit of the aerosol-generating apparatus, the oscillating circuit including: a switching unit; a resonant oscillation feedback circuit including a dielectric heating element arranged for heating the matrix; and measuring electrical parameters associated with the capacitance of the dielectric heating element to determine the properties of the matrix.

[0222] Example Ex84: The method according to Example Ex83 further includes determining the properties of the matrix, wherein the determination includes mapping the measured electrical parameters to the properties of the matrix by means of a mapping function preferably pre-stored on the aerosol generating device.

[0223] Example Ex85: The method according to Example Ex83 or Ex84 further includes performing an operation on the aerosol generating apparatus based on the determined properties of the matrix.

[0224] Example Ex86: The method according to any one of Examples Ex83 to Ex85, wherein the electrical parameters include a power consumption value drawn from the power source, preferably a DC power supply current, and wherein the determined properties of the substrate include the level of dissipation of the substrate.

[0225] Example Ex87: According to the method of Example Ex85 or Ex86, wherein when the depletion level exceeds a threshold, the action includes at least one of shutting off the heating operation, slowing down the heating operation, and instructing the user that the substrate is considered empty.

[0226] Example Ex88: The method according to any one of Examples Ex83 to Ex87, wherein the method steps are performed by an aerosol generating apparatus according to any one of Examples Ex1 to Ex65.

[0227] Example Ex89: A method for calibrating an aerosol generating device, the method comprising the steps of: supplying power from a power source to an oscillating circuit of the aerosol generating device, the oscillating circuit including: a switching unit; and a resonant oscillation feedback circuit including two opposing electrodes E1, E2 for heating an aerosol forming matrix, wherein the matrix is ​​between the two opposing electrodes; measuring the frequency of the electric field between the electrodes; relating the measured frequency to the supplied power; and storing the obtained relationship in a mapping function of the aerosol generating device.

[0228] Example Ex90: The method according to Example Ex89, wherein the method steps are performed by an aerosol generating apparatus according to any one of Examples Ex1 to Ex60 or by a separate calibration apparatus.

[0229] Example Ex91: The method according to Example Ex89 or Ex90, wherein the aerosol generating apparatus is an aerosol generating apparatus according to any one of Examples Ex1 to Ex60.

[0230] Example Ex92: An aerosol generating apparatus according to any one of Examples Ex1 to Ex67, wherein the resonant oscillation feedback circuit is connected between the input and output of the switching unit.

[0231] Example Ex93: According to any one of Examples Ex83 to Ex88, wherein the resonant oscillation feedback circuit is connected between the input and output of the switching unit.

[0232] Example Ex94: According to any one of Examples Ex89 to Ex91, wherein the resonant oscillation feedback circuit is connected between the input and output of the switching unit. Attached Figure Description

[0233] The invention will be further described by way of example only with reference to the accompanying drawings, in which: FIG1 is a schematic illustration of a dielectric-heated aerosol generation system according to an embodiment of the present disclosure; FIG2 is a schematic illustration of an oscillation circuit for the dielectric-heated aerosol generation system of FIG1 according to an embodiment of the present disclosure; FIG3a is a schematic illustration of an oscillation circuit for achieving a 180° phase shift (one phase shift element is exemplarily implemented as a resonant circuit, and the other phase shift element is exemplarily implemented as a capacitor element); FIG3b is a schematic illustration of two different phase shift elements for achieving a 180° phase shift (one phase shift element is exemplarily implemented as a resonant cavity having parallel resonant properties, and the other phase shift element is exemplarily implemented as a capacitor element). Figure 4 shows a schematic diagram of an oscillating circuit (with a capacitor element); Figure 5A-F shows how a quartz analog or quartz equivalent circuit can be derived as a non-limiting example of a parallel resonant circuit according to an embodiment of the present disclosure; Figure 6 shows a frequency analyzer curve of a parallel resonant circuit, illustrating the effect of the switching frequency on the phase shift and impedance of the parallel resonant circuit; Figures 7A-C are equidistant diagrams of inductor pairs with shared mutual inductance coupling in the oscillating circuits of Figures 2-4 according to an embodiment of the present disclosure; Figures 8A-D are equidistant and schematic diagrams of a flat interdigitated electrode arrangement in the oscillating circuits of Figures 2-4 according to an embodiment of the present disclosure; Figure 9 shows an embodiment of the present disclosure. Examples of equidistant and schematic illustrations of tubular interdigitated electrode arrangements in the oscillating circuits of Figures 2 to 4, configured to dielectrically heat aerosol forming matrix 110; Figure 10 shows a schematic illustration of an interdigitated electrode arrangement with varying electrode spacing according to an embodiment of the present disclosure; Figures 11A-D show equidistant and schematic illustrations of tubular interdigitated electrode arrangements in the oscillating circuits of Figures 2 to 4, configured to dielectrically heat aerosol forming matrix 110; Figures 12a-c are schematic illustrations of electrode arrangements for dielectrically heating liquid aerosol forming matrix according to an embodiment of the present disclosure, wherein the electrode arrangements are configured to act as both a heater and a wicking element; Figure 13 shows a temperature... Figure 14 is a schematic diagram of a control system utilizing a power sensing system according to an embodiment of the present disclosure, the control system being used to control the power delivered to the aerosol forming matrix based on a detected aerosol forming matrix temperature; Figure 15 is a schematic diagram of a control system utilizing a power sensing system according to an embodiment of the present disclosure to determine a dissipation level; Figure 16 is a schematic diagram of a control system utilizing a frequency sensing system according to an embodiment of the present disclosure, the control system being used to control the power delivered to the aerosol forming matrix based on the frequency of an alternating electric field detected across the electrode assembly.Figure 17 is a schematic illustration of a broadened frequency response provided by a frequency sensing system, particularly a resonant cavity fabricated, for example, by using impurities or mechanical defects, such that the operating frequency range is covered by the resonant response; Figure 18 is a schematic illustration of a control system utilizing a frequency sensing system to determine a loss level according to an embodiment of the present disclosure; Figure 19 is a schematic illustration of a method for dielectrically heating an aerosol to form a matrix according to an embodiment of the present disclosure; Figure 20 is a schematic diagram showing the different progressions of switching losses relative to electric field strength and transistor cost. Detailed Implementation

[0234] The above and other features and advantages of the exemplary embodiments will become more apparent from the detailed description of the exemplary embodiments with reference to the accompanying drawings. However, the specific structural and functional details disclosed herein are merely representative for the purpose of describing the exemplary embodiments. Furthermore, the exemplary embodiments may be implemented in many alternative forms and should not be construed as being limited to the embodiments set forth herein.

[0235] Therefore, although the exemplary embodiments are capable of various modifications and have alternative forms, embodiments thereof are illustrated by way of example in the accompanying drawings and will be described in detail herein. However, it should be understood that the exemplary embodiments are not intended to be limited to the specific forms disclosed; on the contrary, the exemplary embodiments will encompass all modifications, equivalents, and alternatives falling within the scope of the exemplary embodiments. Throughout the description of the figures, similar reference numerals indicate similar elements.

[0236] Figure 1 is a schematic illustration of a dielectric-heated aerosol generation system 100 according to an embodiment of the present disclosure. The system 100 includes an article 105 comprising an aerosol forming matrix 110, and an aerosol generation apparatus 120 for heating the aerosol forming matrix 110. The aerosol generation apparatus 120 includes a first electrode 130 and a second electrode 135 separated by a cavity 140 for receiving the article 105. The cavity 140 and the article 105 are sized such that when received in the cavity 140, the aerosol forming matrix 110 contacts or is adjacent to both the first electrode 130 and the second electrode 135. Furthermore, the first electrode 130 and the second electrode 135 form part of a feedback loop of an oscillating circuit 150 via a first electrical contact 160 and a second electrical contact 165.

[0237] In other examples, the first electrode 130 and the second electrode 135 may form part of an article 105 including an aerosol-forming matrix 110. In such an embodiment, the cavity size between the first electrical contact 160 and the second electrical contact 165 is set such that when the aerosol-forming article 105 is accommodated within the cavity 140, an electrical connection is formed between the first electrode 130 and the first electrical contact 160, and between the second electrode 135 and the second electrical contact 165.

[0238] In some embodiments, the width of the article 105 including the aerosol-forming matrix 110 is slightly larger than the distance between the first electrode 130 and the second electrode 135, such that the distal end of the aerosol-forming matrix 110 is slightly compressed between the first electrode 130 and the second electrode 135. In some embodiments, the article 105 in its initial uncompressed form has a width that is 5% to 30% larger than the distance between the first electrode 130 and the second electrode 135. This can reduce or prevent air buildup between the first electrode 130 and the second electrode 135 when the aerosol-forming article 105 is received in the cavity 140, and reduce the distance between the first electrode 130 and the second electrode 135 for dielectric heating, thereby improving the load capacitor C. L The accuracy of any measurement or determination of the dielectric properties of the aerosol forming matrix 110 performed by the aerosol generating apparatus 120.

[0239] The aerosol forming matrix 110 may comprise tobacco-based or non-tobacco-based materials (containing aerosol forming materials and one or more active agents or ingredients such as nicotine, pharmaceuticals, plant-derived materials, flavorings), a liquid matrix having one or more active agents or ingredients, or a combination thereof. The aerosol forming matrix 110 may also be a liquid aerosol forming matrix, and thus the aerosol forming article 105 may be in the form of a tube, capsule, or liquid container, and the electrodes 130, 135 may be configured as wicking elements or capillary elements for liquid transfer. For example, it is possible for the first electrode 130 and the second electrode 135 to form a capillary structure that is part of or extends into the internal volume of the aerosol forming article 105, which can heat and evaporate the liquid aerosol forming matrix 110 located within the internal volume. For example, the first electrode 130 and the second electrode 135 can be embodied as parallel plates arranged apart by a distance forming a capillary channel, the distance being, for example, in the range of 0.1 mm to 2 mm, depending on the desired capillary strength or rise. The first electrode 130 and the second electrode 135 can be arranged as two matrices or arrays of needle-like, strip-like, or tabular electrodes of opposite polarity, the two matrices or arrays inserted between each other to form a capillary structure therebetween, for example, having an average distance between adjacent needle-like electrodes, the average distance being in the range of 0.1 mm to 2 mm, depending on the desired capillary strength or rise. In another variation, the wicking element can be a separate element inserted between the two electrodes 130, 135 (e.g., flat or slightly curved electrodes 130, 135).

[0240] The aerosol generating device 120 also includes a power supply 170 and a controller 180 electrically coupled to the oscillation circuit 150. In this embodiment, the power supply 170 may be, for example, a rechargeable lithium-ion battery having one or more lithium-ion battery cells, and the aerosol generating device 120 includes a power connector that enables the aerosol generating device 120 to be connected to an AC power source for recharging the power supply. Providing the aerosol generating device 120 with a power supply such as a battery allows the aerosol generating device 120 to be portable and used outdoors or in locations where AC power is unavailable. In use, when the user activates the aerosol generating device 120, power is supplied from the power supply 170 to the oscillation circuit 150. In this embodiment, the aerosol generating device 120 is activated by the user pressing an activation button (not shown) that may be disposed on the outer surface of the aerosol generating device 120. It should be understood that in other embodiments, the aerosol generating device 120 can be activated in another manner, such as when a user is detected inhaling through a suction sensor located on the mouthpiece (not shown) or when the user is holding the aerosol generating device 120. When power is supplied to the oscillating circuit 150, the oscillating circuit 150 generates an alternating electric field across the first electrode 130 and the second electrode 135 to dielectrically heat the aerosol forming matrix 110 in the cavity 140, thereby releasing volatile compounds.

[0241] The controller 180 enables the application of 1 W / cm² of matrix material per volume over a time period of less than 15 minutes. 3 Up to 25W / cm 3 Between, preferably 1.5W / cm 3 With 15W / cm 3 The average dielectric heating power density within the range between the two electrodes 130 and 135 is used to dielectrically heat the aerosol forming matrix 110. Specifically, during the heat transfer phase, the average dielectric heating power density can be controlled or set to 7 W / cm². 3 Up to 25W / cm 3 Between, preferably 8W / cm 3 Up to 20W / cm 3 Within the range between [specific values]. During the target heating phase (also known as the sustaining heating phase) of the consumption period, the average dielectric heating power density is within 1 W / cm². 3 Up to 7W / cm 3 Between, preferably 1W / cm 3 Up to 5W / cm 3 Within the range between these values. In non-limiting examples, these power densities can be used in heated non-combustible (HnB) applications.

[0242] In yet another exemplary embodiment, the aerosol generation system 100 may be configured to provide 35 W / cm² between a pair of opposing electrodes 130, 135. 3 With 35kW / cm 3 The power density between [various parameters]. The aerosol generation system 100 can be configured to provide [a certain value] at 50 W / cm² between a pair of opposing electrodes 130, 135. 3 With 10kW / cm 3 Between, at 50W / cm 3 With 2.5kW / cm 3 Between or at 50W / cm 3 With 1.25kW / cm 3 The power density between [various parameters]. The aerosol generation system 100 can be configured to provide [a certain value] at 170 W / cm² between a pair of opposing electrodes 130, 135. 3 With 2.5kW / cm 3 Between, at 250W / cm 3 With 2.5kW / cm 3 Between or at 500W / cm 3 With 2.5kW / cm 3 The power density between [the two points]. Preferably, the aerosol generation system 100 can be configured to provide a power density of 1 kW / cm² between a pair of opposing electrodes 130, 135. 3 With 2kW / cm 3 The power densities are between [specific power densities]. In non-limiting examples, these power densities can be used to heat and evaporate liquids during suction in on-demand suction applications, for durations, such as those between 0.5 seconds and 10 seconds.

[0243] For such on-demand suction applications, the dielectric heating loss per volume can be significantly higher than that per volume in HnB applications with heating processes lasting minutes. However, the heated volume can be smaller (approximately 10 mm in on-demand suction applications). 3 Compared to approximately 300mm in HnB applications 3 ).

[0244] The aerosol generation system 100 is also configured to measure the dielectric properties of the aerosol-forming article 105 or the aerosol-forming matrix 110 using electrodes 130, 135 for dielectric heating of the aerosol-forming matrix 110. In some instances, the first electrode 130 and the second electrode 135 may be used to perform dielectric measurements during or separately from the heating process. In this embodiment, the aerosol generation system 100 may be configured to determine the presence of the aerosol-forming article 105 between the first electrode 130 and the second electrode 135. The aerosol generation system may be configured to measure dielectric properties, such as instantaneous values, time evolution, or changes in dielectric properties, for example, to determine whether the aerosol-forming article 105 meets a specific criterion or is a reliable matrix. In this example, the aerosol generation system 100 is also configured to control the heating of the aerosol-forming matrix 110 based on the measured dielectric properties of the aerosol-forming article 105.

[0245] In one exemplary embodiment, the material composition of the matrix 110 of the aerosol forming article 105, which can be dielectrically heated by the aerosol forming apparatus 120, may include tobacco powder or tobacco shred filler.

[0246] As used herein, the term "shredded filler" is used to describe blends of shredded plant material (such as tobacco plant material), particularly including one or more of leaves, processed stems and ribs, and homogenized plant material. Preferably, the shredded filler comprises at least 25% plant leaves, more preferably at least 50% plant leaves, even more preferably at least 75% plant leaves, and most preferably at least 90% plant leaves.

[0247] The shredded filler suitable for use with the present invention is generally similar to that used in conventional smoking products. The shred width of the shredded filler is preferably between 0.3 mm and 2.0 mm, more preferably between 0.5 mm and 1.2 mm, and most preferably between 0.6 mm and 0.9 mm.

[0248] The aerosol generating matrix 110 may include shredded filler in the range of 80 mg to 400 mg. For example, the aerosol generating matrix 110 may include shredded filler in the range of 100 mg to 300 mg, shredded filler in the range of 100 mg to 250 mg, shredded filler in the range of 125 mg to 200 mg, or shredded filler in the range of 140 mg to 180 mg, such as shredded filler in the range of about 150 mg.

[0249] The aerosol forming matrix 110 of the aerosol forming article 105 may contain an aerosol forming agent. In the case where the aerosol forming matrix 110 includes filamentous filler, the filamentous filler may be impregnated with the aerosol forming agent. Impregnation of the filamentous filler can be accomplished by spraying or by other suitable application methods.

[0250] Preferably, the aerosol forming agent comprises one or more of glycerol and propylene glycol (PPG). The aerosol forming agent may consist of glycerol or propylene glycol, or a combination of glycerol and propylene glycol. The aerosol forming matrix 110 may contain any amount of aerosol forming agent. For example, the aerosol forming matrix 110 may contain 5% to 25% by weight of the aerosol forming agent. For example, the aerosol forming matrix 110 may contain 10% to 20% by weight of the aerosol forming agent, or 15% to 20% by weight of the aerosol forming agent. Preferably, the aerosol forming matrix 110 contains about 18% by weight of the aerosol forming agent. The weight percentage of the aerosol forming agent is given based on the dry weight of the shredded filler, with the remainder being tobacco.

[0251] The aerosol forming matrix 110 may have a density not exceeding 0.45 g / cm³, 0.4 g / cm³, 0.36 g / cm³, 0.3 g / cm³, or 0.25 g / cm³. The aerosol forming matrix 110 may have a density of at least 0.1 g / cm³. For example, the aerosol forming matrix 110 may have a density of at least 0.15 g / cm³, at least 0.2 g / cm³, or at least 0.28 g / cm³.

[0252] The aerosol forming matrix 110 can have different shapes, such as cubic, cuboid, bag-shaped, or cylindrical, and is preferably substantially cylindrical, with a length between 10 mm and 15 mm, such as between 11 mm and 14 mm, preferably about 12 mm, and a diameter between 4.5 mm and 8 mm, such as between 6.5 mm and 7.5 mm, preferably about 7 mm.

[0253] Suitable aerosol forming matrices and articles comprising filament fillers include those described in WO2022 / 074240 and / or WO2022 / 074158, which are incorporated herein by reference in their entirety.

[0254] In another exemplary embodiment, the material composition of the aerosol forming matrix 110 of the aerosol forming article 105, which can be dielectrically heated by the aerosol forming apparatus 120, may include reconstituted tobacco, such as one or more sheets of homogenized tobacco material manufactured by a cast leaf process.

[0255] When the aerosol forming matrix 110 contains homogenized tobacco material, the tobacco material preferably comprises granular tobacco obtained by grinding or otherwise pulverizing tobacco leaves. This homogenized tobacco material may have a tobacco content of at least about 40% or at least about 50% based on dry weight. In other embodiments, the homogenized tobacco material may have a tobacco content of 70% or more, such as between 70% and 80% based on dry weight.

[0256] In yet another exemplary embodiment, the aerosol forming matrix 110 may include a plurality of tobacco beads or particles. For example, the average diameter of the plurality of beads or particles may be between 0.5 mm and 10 mm. The matrix 110 may include 2 to 200 beads or particles, or 5 to 200 beads or particles, or 10 to 100 beads or particles, or 20 to 75 beads or particles, or 30 to 50 beads or particles, or 40 to 50 beads or particles. The total weight of the plurality of beads or particles in the aerosol generating article 105 may be between 50 mg and 350 mg, or between 100 mg and 300 mg, or between 125 mg and 250 mg, or between 150 mg and 200 mg. The beads or particles may contain tobacco, an aerosol forming agent, and a hydrocolloid binder.

[0257] The aerosol forming matrix 110 may include one or more intrinsic binders that are endogenous binders for tobacco, one or more exogenous binders that are exogenous binders for tobacco, or combinations thereof, to help agglomerate particulate tobacco. Alternatively or additionally, the aerosol forming matrix 110 may contain other additives, including but not limited to tobacco and non-tobacco fibers, aerosol forming agents, humectants, plasticizers, flavorings, fillers, aqueous solvents and non-aqueous solvents, and combinations thereof.

[0258] Suitable external binders for inclusion in the aerosol-forming matrix 110 are known in the art, including but not limited to: gums, such as guar gum, xanthan gum, gum arabic, and locust bean gum; cellulose binders, such as hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, and ethyl cellulose; polysaccharides, such as starch; organic acids, such as alginic acid; conjugate base salts of organic acids, such as sodium alginate, agar, and pectin; and combinations thereof. For example, the aerosol-forming matrix 110 may contain between 1% and 5% of an external binder based on dry weight, such as between 1.5% and 3.5% based on dry weight, preferably about 2% based on dry weight. Preferably, the external binder is guar gum.

[0259] Suitable non-tobacco fibers for inclusion in the aerosol-forming matrix 110 to reinforce the material are known in the art and include, but are not limited to: cellulose fibers; cork fibers; hardwood fibers; jute fibers; and combinations thereof. For example, the aerosol-forming matrix 110 may contain between 2% and 6% non-tobacco fibers on a dry weight basis, such as between 3% and 5% on a dry weight basis, and preferably about 4% on a dry weight basis. Preferably, the non-tobacco fibers are cellulose fibers.

[0260] Aerosol forming matrix 110 may contain an aerosol forming agent. Preferably, the aerosol forming agent comprises one or more of glycerol and propylene glycol. The aerosol forming agent may consist of glycerol or propylene glycol, or a combination of glycerol and propylene glycol. Aerosol forming matrix 110 may contain any amount of aerosol forming agent. For example, aerosol forming matrix 110 may contain 5% to 25% aerosol forming agent. For example, aerosol forming matrix 110 may contain 10% to 20% aerosol forming agent, or 15% to 20% aerosol forming agent. Preferably, aerosol forming matrix 110 contains about 18% aerosol forming agent. The weight percentage of the aerosol forming agent is given based on the dry weight of aerosol forming matrix 110.

[0261] Preferably, the aerosol forming matrix 110 has a weight between 220 mg and 350 mg. For example, the aerosol forming matrix 110 may have a weight between 240 mg and 320 mg, between 250 mg and 310 mg, between 240 mg and 280 mg, or between 290 mg and 330 mg.

[0262] The aerosol forming matrix 110 may have a density not exceeding 0.75 g / cm³, 0.68 g / cm³, 0.67 g / cm³, 0.59 g / cm³, or 0.56 g / cm³. The aerosol forming matrix 110 may have a density of at least 0.5 g / cm³. For example, the aerosol forming matrix 110 may have a density of at least 0.55 g / cm³, at least 0.56 g / cm³, or at least 0.64 g / cm³.

[0263] The aerosol forming matrix 110 may be cylindrical, and preferably substantially cylindrical, with a length between 10 mm and 15 mm, such as between 11 mm and 14 mm, preferably about 12 mm, and a diameter between 4.5 mm and 8 mm, such as between 6.5 mm and 7.5 mm, preferably about 7 mm, and preferably may have a matrix volume in the range of 0.16 cubic centimeters to 0.75 cubic centimeters.

[0264] In yet another exemplary embodiment, the aerosol forming matrix 110 may be a non-tobacco-based matrix and / or a substantially tobacco-free matrix. The aerosol forming matrix 110 may be a cellulose-based matrix, such as those described in WO2020 / 207733, WO2023 / 126494 and / or WO2022 / 248378, which are incorporated herein by reference in their entirety.

[0265] Figure 2 is a schematic illustration of an oscillation circuit 250 in the aerosol generation system 100 of Figure 1 according to an embodiment of the present disclosure. The oscillation circuit 250 includes a switching unit 260 interconnected with a resonator feedback loop 270 for providing a self-oscillating signal to the switching unit 260. The feedback loop 270 is connected between the input and output of the switching unit 260. The switching unit 260 includes a single transistor, such as a bipolar junction transistor (BJT) or a field-effect transistor (FET).

[0266] The oscillation circuit 250 may further include a choke coil 280 that acts on the input of the feedback loop 270 to provide a stimulation signal, such as a stimulation voltage. The oscillation circuit also includes a bias unit 290 that acts on the feedback loop 270 to provide a variable or controllable bias signal (such as a bias voltage) for setting operating conditions. In the illustrated variant, the feedback signal can be described as a voltage. The output voltage U of the switching unit 260... OUT Coupled to feedback loop 270, thereby converting the input voltage U IN A feedback switching signal in the form of a feedback loop 270 is provided to the switching unit 260. The configuration of the feedback loop 270 causes the output signal (e.g., the output voltage U of the switching unit 260) to be such that... OUT It can undergo a phase transition, and the input voltage U of the switching unit 260... IN The phase is reversed at the point of contact for resonant oscillation. In other configurations, the current can be used as a feedback signal, where the switching unit 260 includes a BJT.

[0267] Feedback loop 270 is configured to self-oscillate and will oscillate at or near a given resonant frequency determined by the values ​​of the passive components of feedback loop 270. Feedback loop 270 is configured to provide the output voltage U from switching unit 260.OUT To input voltage U IN A 180° phase shift is used for oscillation, and in addition, transistor T is configured for inverting operation.

[0268] As shown in Figures 3a and 3b, the feedback loop 270 includes a resonant circuit 272, which includes a load capacitor C. L The feedback loop 270 also includes a capacitor 274 that provides a second 90° phase shift or quarter-wavelength offset to the feedback signal, such that the feedback signal arriving at the input of the switching unit 260 is inverted and phase-shifted by 180°. The switching unit 260 itself is configured for inverting switching operation to provide a second 90° phase shift or quarter-wavelength offset to the input voltage U of the switching unit 260. IN With output voltage U OUT A 180° phase shift is provided between them.

[0269] The resonant circuit 272 includes a first electrode 130 and a second electrode 135, which together form a load capacitor C. L When the aerosol forming matrix 110 is located between the first electrode 130 and the second electrode 135, it forms a load capacitor C. L Part of it. Importantly, the load capacitor C... L It is formed in the feedback loop 270 and not at a separate output or portion of the separate circuit system connected to the switching unit 260. This allows for the crossing of the load capacitor C. L The electrodes generate a high-frequency oscillating voltage (which is necessary for sufficient and efficient dielectric heating of the aerosol forming matrix 110) without having an additional output or circuitry leading to the already resonant feedback loop 270 (which would introduce unnecessary losses and circuit complexity). The resonant circuit 272 may include a series resonator circuit or a parallel resonator circuit, examples of which are described in more detail below.

[0270] In an alternative embodiment, the resonant circuit 272 may include a resonant cavity 272, as shown in FIG3c. The resonant circuit 272 including the resonant cavity may have an internal volume configured to receive the aerosol forming matrix 110, for example, having an opening for insertion into the aerosol forming matrix 110. In an example, the resonant circuit 272 including the resonant cavity may be configured to... / 4 resonator. The resonant circuit 272, including the resonant cavity, can be configured to behave like an RLC circuit. The inductor L and capacitor C are arranged in parallel with each other to have a frequency of parallel resonance or near-parallel resonance that can be excited by the switching unit 260. The resonant circuit 272, including the resonant cavity, can be coupled to the feedback loop 270 using one or more of capacitive coupling, inductive antenna coupling (magnetic coupling), direct electrical coupling, or window coupling (e.g., coupling with a loop).

[0271] The resonant circuit 272, including the resonant cavity, can have any shape, but is preferably cylindrical or cuboid. In one embodiment, the resonant cavity can be configured as an open-loop resonator.

[0272] Figure 4 illustrates an oscillation circuit 350 according to a non-limiting exemplary embodiment of the present disclosure. The oscillation circuit 350 includes circuits having an intrinsic capacitance C. i A switching unit 260 in the form of a transistor T is provided. Furthermore, the transistor T is configured for inverting operation, for example, as an inverting common-source FET, MOSFET, or common-emitter BJT. The source terminal of the transistor T can be coupled to a DC power supply via a choke coil 280. A feedback loop 270 extends between the gate terminal and the source terminal of the transistor T. The feedback loop 270 includes a resonant circuit 272, which includes a load capacitor C. L The load capacitor has a first electrode 130 and a second electrode 135 separated by an aerosol forming matrix 110. In the illustrated variant, the resonator circuit 272 also extends via a delay line D. L and connected in series to delay line D L Capacitor C2 is connected to ground. Circuit 350 also includes a delay line D. L A bias unit 290 is coupled to the gate terminal of transistor T. As shown in Figure 4, the bias unit 290 is electrically connected to the delay line D. L Between the bias unit 290 and capacitor C2, the high oscillation frequency of the feedback loop 270 is slightly isolated. Delay line D L It can be placed elsewhere, such as somewhere else in the feedback loop 270.

[0273] Delay line D L This is a time-delay element, such as an element with inductive behavior, used to slow down the arriving voltage wave from feedback loop 270 during the oscillation period. This allows resonant circuit 272 to be tuned to the desired switching and oscillation frequency to shift the oscillation frequency away from the natural resonant frequency given by resonant circuit 272. This ensures that oscillation circuit 350 remains within a predefined frequency operating range to provide the necessary anti-phase or 90° phase-shifted feedback, and also ensures that feedback loop 270 has low impedance to provide high gain, as described in more detail below.

[0274] The oscillation circuit 350 is shown as having an arrangement on the load capacitor C L Electrical contacts 160 and 165 are located on both sides of the electrode. In some embodiments, the first electrode 130 and the second electrode 135 may be removable from the oscillation circuit 350 or may form part of the aerosol forming article 110. In such an embodiment, the electrical contacts 160 and 165 provide an electrical connection between the first electrode 130 and the second electrode 135 and the feedback loop 270. The load capacitor C... L In embodiments where the aerosol forming matrix 110 is fixed within the feedback loop 270, for example, such that it can be inserted into and removed from the cavity formed between the first electrode 130 and the second electrode 135, the electrical contacts 160, 165 provide electrical connections from the first electrode 130 and the second electrode 135 to the next component (e.g., inductors L1 and L2) in the feedback loop 270.

[0275] Regarding the power supply voltage, a DC power supply voltage is provided, preferably within a range suitable for battery operation using one or more standard battery cells. Preferably, the DC power supply voltage is below 14V. For example, it is possible to operate the oscillating circuit 350 on a single battery cell, such as an 18650 battery cell (Li-ion) or a similar battery cell (which provides 3.2V to 3.9V). However, more preferably, the voltage of an exemplary 3.5V to 7V battery cell used for the power supply can be boosted, for example, by a DC-DC converter (e.g., a boost circuit) or a voltage multiplier. Alternatively or additionally, two or more battery cells can be used in series, or other configurations or arrangements that allow for increased voltage from one or more battery cells can be used. It is also possible to have a controllable output voltage (e.g., a DC-DC converter, a voltage regulator) to control the heating temperature by changing the DC supply voltage, or to boost the voltage (e.g., boost to 10V-12V) to obtain maximum power during the preheating phase to accelerate the preheating phase, with the goal of rapidly reaching the aerosolization temperature. Controlling the DC power supply voltage is one way to make it possible to rapidly change the heating power even though the oscillating circuit 350 is oscillating freely.

[0276] Capacitor C1 is arranged in parallel with transistor T, and therefore in parallel with the inherent capacitor of transistor T (e.g., a field-effect transistor). This contributes to less voltage-dependent oscillations and frequencies, stabilizes oscillations, and also improves overall dielectric heating efficiency. The capacitance of capacitor C1 is chosen to be greater than the maximum inherent capacitance C of transistor T under operating conditions. iThis makes the effect of inherent transistor variations based on frequency, temperature, etc., on the feedback loop 270 much smaller or negligible. For example, in a non-limiting embodiment, the value can be in the range of 2pF to 100pF, more preferably in the range of 5pF to 50pF.

[0277] Capacitor element 274 includes capacitor C2 disposed at the output or end of resonant circuit 272. In one embodiment, capacitor element 274 includes more than one capacitor. As described above, capacitor element 274 has the function of providing a 90° phase shift to the feedback voltage of feedback loop 270 with minimal losses or other undesirable effects, and therefore it needs to have a high quality factor or Q factor, preferably above 1000 at 100MHz. Compared to capacitor C1, the capacitance value of capacitor C2 of capacitor element 274 should be relatively high, for example, in the range of 500pF to 100nF, more preferably in the range of 1nF to 50nF, which results in low impedance of capacitor element 274. In a variation, capacitor element 274 can be implemented as an RC network to provide a 90° phase shift, for example using a network of two single-resistor capacitors, having two capacitors in the feedback loop, each capacitor connected to ground via a resistor.

[0278] The resonant circuit 272, together with the capacitor element 274, provides power from the output voltage U. OUT To input voltage U IN The transistor T (e.g., FET) is configured for inverting operation, thereby providing another 180° phase shift and voltage gain. This results in a phase shift across the load capacitor C. L The resonance or near-resonance oscillation of electrodes 130 and 135 and the voltage U amplified compared to the DC power supply voltage. L When near resonant operation, the resonant circuit 272 behaves inductively, exhibiting a high Q factor. Furthermore, the feedback loop 270 is impedance-matched to the transistor T with an impedance of approximately 500mΩ to 8Ω, preferably approximately 2Ω, to provide high gain, thereby causing a gain across the load capacitor C. L The increased voltage. Moreover, preferably, this gain is achieved without using additional voltage or current amplification passive components (such as tapped inductors or transformers located in the circuit forming feedback loop 270), because such passive components are difficult and detrimental to operate and design at frequencies greater than 50 MHz. Preferably, the impedance of the resonant circuit 272 and the capacitor C2 is matched to the impedance of the transistor T; more preferably, the resonant circuit 272 and the transistor T are substantially impedance matched.

[0279] The combination of capacitor C1, the feedback loop with resonant circuit 272, and capacitor element 274 can also be described as generating a bandpass filter or a Pi or π network with a 180° phase shift. In the illustrated embodiment, the resonant circuit 272 of the feedback loop 270 is not connected to ground but is suspended, with its ends at each capacitor C1 and C2. This eliminates the direct ground connection at either end of the resonant circuit 272, thereby reducing the effects of stray elements and ground for more predictable operation.

[0280] At the operating frequency, including the load capacitor C L The resonant circuit 272 acts as an inductive load providing the first 90° phase shift (also known as a quarter-wavelength phase shift), and the capacitive element 274, which includes a high-quality factor capacitor C2 connected to ground, provides the second 90° phase shift or quarter-wavelength phase shift.

[0281] The oscillator circuit 350 can be described or characterized as a Pierce oscillator circuit with a modified feedback loop 270, wherein the physical quartz element is replaced by a quartz analog or quartz electrical equivalent circuit to provide inverted feedback to the switching unit 260, which also operates in inverted mode. In some embodiments, the oscillator circuit 272 can be configured based on other resonant feedback loop oscillator circuits, such as, but not limited to, using a Colpitts or Hartley type oscillator (using an inverting transistor T).

[0282] Figures 5A to 5F illustrate how variations of the parallel resonator circuit PRC can be used to derive a quartz analog or quartz equivalent circuit, which can be used as exemplary and non-limiting embodiments of the resonant circuit 272. The quartz analog or quartz equivalent circuit can have parallel resonance at a given frequency. This can be viewed as a circuit with two branches, one representing mechanical oscillation and the other representing electrical behavior, as shown in Figures 5A and 5B. The mechanical oscillation is caused by a load capacitor C. L and inductor L TOT The first branch is represented by [the first branch]. The electrical oscillation is formed by [a component] arranged in parallel with the first branch, having a capacitor C. E The second branch is represented. This configuration causes two capacitors C to... L and C E The series connection (visible around the loop formed by the two branches) makes capacitor C E This will reduce the total capacitance of the equivalent circuit. Furthermore, this circuit provides an inductive phase shift of approximately 90° within a defined frequency range.

[0283] Referring now to Figure 5C, one branch of the parallel resonator circuit PRC includes an inductor L connected in series with the first branch. TOT and load capacitor C LAs shown in Figure 5D, it can be achieved by using L TOT Decomposed into load capacitor C L Two inductors, L1 and L2, on either side are used to improve this branch, providing a decomposed inductor or decomposed coil design as well as across the load capacitor C. L voltage U L A more symmetrical application of the capacitor C improves the dielectric heating efficiency. To provide parallel resonance, due to the capacitor C... E For capacitor C L The minimum capacitance effect, the capacitor C of the second branch E An inductor (as shown in Figure 5F) can be used as a replacement.

[0284] In a non-limiting example starting with the decomposed inductors L1 and L2 of the resonant circuit 272 in Figure 5D, inductors L1 and L2 can be magnetically coupled to form a mutual inductance M, thereby forming a parallel circuit branch or a second branch of the resonant circuit 272, as shown in Figure 5E. Mutual magnetic coupling can be achieved by bringing the two inductors L1 and L2 close together, aligning the winding axes of the coils; or by using mutual magnetic cores; or both. This has the advantages of providing a parallel resonator circuit PRC without using additional wires for the second branch, and without requiring additional windings or separate magnetic cores for the second parallel-arranged inductors. This also allows for and facilitates the inductive coupling and voltage U of the two inductors L1 and L2. L At load capacitor C L A balanced, symmetrical arrangement. Two branches (where the first branch L1-C) L -L2 and L with inductor L E The second branch (representing the symmetry of two mutual inductance values) in either direction contributes to the load capacitor C. L The symmetrical balance of the voltage on the electrodes thus reduces the voltage across the load capacitor C. L The loss generated at the point. This principle of decomposing the inductor can also be called decomposing the coil resonator.

[0285] The resonant circuit 272 can also be implemented as shown in Figure 5F, where the mutual inductance M (seen twice due to reciprocity) is provided by a separate inductive element (e.g., inductor L). E )replace.

[0286] The values ​​of the components in this resonant circuit 272 are preferably selected within the following exemplary and non-limiting ranges. TOT It can be in the range of 10nH to 50nH, more preferably between 15nH and 40nH, which is equivalent to L1 plus L2, L E It can be in the range of 7nH to 30nH, more preferably between 10nH and 20nH, and the load capacitor C LThe value can be between 0.5 pF and 5 pF, more preferably between 1 pF and 3 pF.

[0287] The resonant circuit 272 can be configured to provide another type of tank circuit with a 90° phase shift over a given frequency range. In one embodiment, the resonant circuit 272 can be implemented as a series resonant circuit having a load capacitor C connected in series with one or more inductive elements. L It is configured to provide an inductive response or a 90° phase shift within a given frequency range suitable for dielectric heating.

[0288] In order to load capacitor C L The required dielectric losses are generated in the process, necessitating high frequencies. The dielectric losses will be related to the dielectric losses applied to the load capacitor C. L The frequency of the alternating voltage (in this case, the oscillation frequency f of the oscillating circuit). s The switching frequency f increases slightly proportionally. However, higher switching frequencies f s This causes significant switching losses in transistor T. When using very high switching frequencies (e.g., 1 GHz or higher), expensive circuit design is necessary to make the circuit operational (e.g., GaN transistors, such as GHz-type circuit designs).

[0289] To compensate for the lower switching frequency, the load capacitor C can be bypassed. L Provides a higher oscillation AC voltage U L (e.g., measured by RMS or peak voltage) to deliver the necessary power to the load capacitor C L When it is necessary to increase the switching frequency f s With increasing the load capacitor C L To achieve a balance between the voltages on the load capacitor C, which may include the aerosol forming matrix 110, in order to increase the heating power (and thus increase the load capacitor C). L Dielectric loss P in L At this time, increasing the voltage has a stronger effect on the heating power than increasing the frequency, because voltage and power have a quadratic relationship. Load capacitor C L The dielectric loss also depends on the distance between the two electrodes 130 and 135, which affects the electric field strength E across the aerosol-forming matrix 110. F .

[0290] As an example, Figure 20 illustrates the depiction of a given dielectric loss P. L And for a given geometry / arrangement of electrodes E1 and E2, schematic diagrams of various curves showing switching losses versus electric field strength and transistor cost, with non-restrictive and non-exclusive values. The figure illustrates the changes in switching frequency f with... s Increasing the switching frequency f reduces efficiency; to ensure operability, the switching frequency f should be increased.s The price of transistors increases exponentially, and also with the switching frequency f. s Increasing the electric field strength decreases it.

[0291] For mobile, portable designs of human-operated dielectric heaters, serious concerns exist regarding voltage insulation and potential dielectric breakdown due to contamination of the matrix material S of the aerosol-forming matrix 110 and its generally heterogeneous nature. Therefore, for handheld and human-operated portable devices, there are safety considerations regarding the switching frequency f. S and electric field strength E F The operating range. The electric field strength depends on the field applied to capacitor C. L voltage U L (i.e., the voltage intensity of the alternating voltage) and the maximum distance d between the first electrode 130 and the second electrode 135.

[0292] Preferably, the switching frequency f s To limit it to a certain range, first ensure that it crosses the load capacitor C. L Sufficient power loss P L Furthermore, it avoids excessive switching losses. Limit the switching frequency f. s The value of f allows for the use of simple circuit designs, such as, but not limited to, LDMOS or other standard transistors used in RF circuits. Preferably, the switching frequency f... s The frequency range should be between 100MHz and 1.2GHz, more preferably between 150MHz and 1GHz, and even more preferably between 200MHz and 900MHz. Meanwhile, considering impurities and heterogeneous matrix design, the use of thin electrodes (e.g., but not limited to 1mm-10mm) that can be positioned close to each other, potential exposure to or close proximity to the human body, and potential improper human manipulation, the load capacitor C should be... L The maximum electric field strength between the electrodes is limited to a reasonable value that allows for simple electrical insulation materials and design. Preferably, the average electric field strength across the electrodes of the load capacitor is at most 120 V / mm, more preferably at most 100 V / mm, and even more preferably at most 80 V / mm.

[0293] Preferably, under nominal heating operation (excluding the start-up or heating phase, which may be less efficient and lasts less than 30 seconds), the heating efficiency should be at least 60% (desired power loss P). L Compared to all other losses, other losses can include switching losses of transistor T, losses caused by the bias circuit and choke, inductor-resistance losses of inductors L1 and L2, capacitive-resistance losses from capacitors C1 and C2, and resistive losses of electrodes E1 and E2 and the circuit. As an example, the total power could be 10W, while the effective power or heating loss P...L The power should be 6W or higher, where non-heating losses or other heating losses in the matrix 110 not caused by the first electrode 130 and the second electrode 135 are 4W or less. Power losses exceeding 6-7W are undesirable for handheld devices, and more preferably less than 5W under nominal heating conditions or other operations that may last for more than 30 seconds.

[0294] In order to achieve the input voltage U IN With output voltage U OUT With appropriate anti-phase effect and a 180° phase shift in feedback loop 270, oscillator circuit 350 must remain within the frequency operating range where the behavior of feedback loop 270 is highly inductive. In examples including parallel resonant circuits (PRCs), the series resonant frequency f SER (Resonant frequency) is relatively close to the parallel resonant frequency f PAR (Also known as the anti-resonant frequency). If the oscillation (switching) frequency f of the PRC... S Exceeding the parallel resonant frequency f PAR In this case, feedback loop 270 will operate capacitively and will not provide the necessary phase reversal to feedback loop 270. Furthermore, the equivalent impedance of the circuit will increase to an excessive level for efficient dielectric heating because it does not provide the necessary gain.

[0295] The oscillation in feedback loop 270 will naturally approach the parallel resonant frequency of resonant circuit 272. However, the delay line D... L The addition of [a certain element] can introduce a limitation that restricts the oscillation frequency to below the parallel resonant frequency f. PAR A slight time delay. Figure 6 shows the frequency analyzer curves of the exemplary resonant circuit 272, specifically the curves of the parallel resonant circuit PRC, which show the oscillation (switching) frequency f. S (It exhibits series resonance at 855MHz and parallel resonance at 1.246GHz), the relationship between the phase shift across the PRC (with a relatively flat 90° frequency response between the two resonant frequencies) and the effective impedance of the PRC. More specifically, as can be seen from Figure 6, at the parallel resonant frequency f... PAR Previously, the 90° phase shift began to decrease. At the parallel resonant frequency f... PAR Subsequently, the phase shift response drops below 0°, exhibiting capacitive behavior, and the impedance becomes very high, for example, 2.4kΩ. The ideal operating frequency range is closer to the series resonant frequency f. SER The phase shift remains 90°, and the impedance response is low, preferably less than 2Ω, more preferably less than 1Ω. The parallel resonant frequency f... PAR It can be higher than 1GHz, for example, from 1GHz to 1.5GHz, while the actual switching frequency f SIt can be below 1 GHz, and this lower switching frequency f S By delay line D L cause.

[0296] Ideally, the oscillation (switching) frequency f S It should be set below the parallel resonant frequency f. PAR But higher than the series resonant frequency f SER This is to ensure that two conditions are met: firstly, (i) the resonant circuit behaves inductively to provide a 90° phase shift, and secondly, (ii) the impedance of the resonant circuit (and therefore feedback loop 270) is low, as illustrated in Figure 6. For example, feedback loop 270 is at the oscillation (switching) frequency f of the oscillating circuit. S The resulting impedance can be in the range of approximately 100mΩ to 2Ω. Preferably, the delay line D... L Configured to make the oscillation (switching) frequency f S Distance from series resonant frequency f SER The parallel resonant frequency f of the distance PAR More recently, this maintains a low resonant circuit impedance when operating within a frequency range that provides a 90° phase shift. This is achieved by delay line D. L The resulting time delay needs to be relatively short because the series resonance and parallel resonance of the parallel oscillating circuit PRC are close to each other relative to the total frequency range. Preferably, the delay line D... L The resulting delay acting on feedback loop 270 should be at the parallel resonant frequency f. PAR The period is between 5% and 35%, provided that the above two conditions (i) and (ii) are met. In the embodiment, the delay line D... L The resulting delay acting on feedback loop 270 at the parallel resonant frequency f PAR The period and series resonant frequency f SER The difference between the periods is within 35% to 90%, provided that conditions (i) and (ii) above are met, more preferably within 50% to 85%. For example, taking the illustration in Figure 6 as a non-limiting numerical example, assume the parallel resonant frequency f PAR It is 1.25 GHz, therefore has a period of 800 picoseconds, and a series resonant frequency f. SER The frequency is 855MHz, and therefore has a period of 1169ps, so f PAR and f SER There is a difference of 369 ps between their periods. This is due to the delay line D. L The resulting time delay can be within the above range, for example, f. PAR with f SERThe period difference between them is 70%, which is 258 ps, thus ensuring that the feedback loop 270 has the desired inductive behavior and low impedance necessary to provide high gain anti-phase feedback.

[0297] Preferably, the delay line D L A zigzag conductive element is implemented to exhibit inductive behavior, for example, a zigzag element having two (2) to twelve (12) zigzag branches, more preferably three (3) to eight (8) zigzag branches. Such an implementation exhibits minimal stray inductive and capacitive behavior. Various delay line structures can be used to provide the desired functionality, such as Ω-shaped coils, single planar coils, flat inductors, wavy lines, zigzag lines, or sawtooth lines. It is also possible to provide the desired delay line functionality through specific transmission line designs. For example, it is possible for delay line D... L The physical components are implemented as conductors in a printed circuit board, for example, as a microstrip patch antenna. In some embodiments, a low-pass filter can be used as a delay line D. L However, this will affect the shape of the oscillating voltage, while the delay line D, which provides a short time delay through the inductive effect, will... L This will not affect the waveform. In the embodiment shown in Figure 4, the delay line D L It is placed between the feedback loop output of the resonant circuit 272 and the capacitor element 274, but other arrangements are also possible.

[0298] Figures 7A-C are equidistant illustrations of a decomposed coil resonator with mutual inductive coupling in the oscillating circuits of Figures 2-4 according to embodiments of the present disclosure. In the example of Figure 7A, the two inductors L1 and L2 are each formed as a single winding, such as a single toroidal coil. The central axes of the windings of each coil are substantially coincident with each other, and the planes formed by each single-winding inductor are parallel to each other and also very close to each other. This establishes mutual inductance between inductors L1 and L2 without the need for a magnetic core M. C If necessary, this can be achieved by adding a magnetic core M that passes through or at least partially passes through each winding of L1 and L2. C To further increase the mutual inductance M to achieve the desired inductance level, the distance between the two planes arranging the windings can be increased to minimize the capacitive effect between them. Preferably, the windings of inductors L1 and L2 are wound in the same direction around a coincident winding central axis, or in the presence of core M... C In the case of core M C Alternatively, they can be wound around a central axis. In this way, the magnetic flux generated by both coils L1 and L2 is enhanced, rather than canceled out. In other words, the two inductors L1 and L2 are positioned around the magnetic core M. C Alternatively, a continuous winding coil around the central axis of the winding without using a core, wherein two winding regions form two inductor coils L1 and L2.

[0299] Figure 7B shows an alternative decomposed coil resonator arrangement, in which an Ω-shaped loop is used instead of a full-length loop for L1 and L2. Other winding shapes are also possible while providing essentially the same functionality.

[0300] In some instances, it is possible to use inductor coils L1, L2 with smaller diameters, but with a number of loops or turns. Preferably, the number of turns in each inductor coil L1, L2 is no more than five (5), preferably less than three (3) turns, and preferably no more than one (1) turn. To further reduce the capacitive coupling between L1 and L2, the inductors L1, L2 of the decomposed coil resonator of FIG7B are arranged as planar coils of Ω shape, single-winding or double-winding coils, both on the same surface or plane, and therefore not aligned parallel to each other. This is desirable because the capacitive effect between the two inductors L1 and L2 can provide undesirable additional dielectric losses. In this embodiment, through core M C The magnetic coupling is achieved via a U-shaped core, in which each leg passes through the center of each planar coil L1, L2.

[0301] Both Figures 7A and 7B show an embodiment of the resonant circuit 272 as a complete parallel resonant circuit PRC, formed by the second branch created by the mutual inductance M between inductors L1 and L2.

[0302] It is also possible that this can be achieved through simple proximity of the two inductor coils L1 and L2, without the use of a magnetic core M. C (As shown in Figure 7C), or by winding the coils of inductors L1 and L2 together, a mutual inductance M between L1 and L2 is generated. The electrode arrangement in Figure 7C includes parallel electrode plates E1 and E2 with curved edges to reduce hot spots in the electric field formed around the boundaries of the electrode plates.

[0303] Figures 7A and 7B show an electrode arrangement including a pair of parallel-aligned electrode plates 130, 135; however, other electrode arrangements are also possible.

[0304] Figures 8A-D are schematic illustrations of a flat, interdigitated electrode arrangement for the oscillating circuits of Figures 2-4 according to embodiments of the present disclosure. Using interdigitated electrodes allows for more uniform electric field generation, which can be used to avoid hot spots in the aerosol formation matrix. Figure 8A shows an electrode arrangement including two electrodes. The first electrode includes one or more extensions, and the second electrode includes corresponding one or more recesses for receiving one or more extensions of the first electrode. In some other instances, both the first and second electrodes each include a combination of extensions and recesses configured to align with corresponding recesses and extensions in an opposing electrode.

[0305] Figures 8B and 8C show an electrode arrangement including multiple electrodes for each polarity, wherein each electrode is positioned adjacent to an electrode of the opposite polarity.

[0306] However, the shape and geometry of the electrode can vary, and it is preferred that the edges and corners of the electrode are rounded, for example, having a radius in the range of about 0.15 mm to 2.5 mm, in order to “soften” the peak of the electric field at the edges and corners.

[0307] As shown in Figure 8D, it is possible to fabricate an interdigitated electrode arrangement for a one-sided flat aerosol forming matrix 110. However, dielectric heating can be improved by providing a second electrode arrangement identical to that shown in Figure 8D on the opposite side of the aerosol forming matrix 110. The electrodes of the second electrode arrangement can be configured to be aligned with the electrodes of the first electrode arrangement having opposite polarities.

[0308] Alternatively, as shown in FIG9, the interdigitated electrode arrangement may include a first electrode and a second electrode, which are configured to intersect each other around a cylindrical axis to form a tubular structure. In this embodiment, there are two pairs of three-finger electrodes. Preferably, the tubular structure may have a diameter between 5 mm and 9 mm. The tangential distance between electrodes of opposite polarities may be between 0.5 mm and 3 mm, preferably between 0.7 mm and 2.2 mm.

[0309] Figure 10 illustrates an embodiment in which the distance between electrodes of opposite polarity varies between different regions of the electrode arrangement. This can facilitate modification of the electric field intensity in different regions of the electrode arrangement, thereby modifying the heating power delivered to different regions of the aerosol forming matrix 110 heated using the electrode arrangement to provide segmented, zoned, or partial heating.

[0310] Figures 11A-B show equidistant and schematic illustrations of tubular interdigitated electrode arrangements for the oscillating circuits of Figures 2 and 3, configured to dielectrically heat an aerosol-forming matrix 110 positioned within a central cavity formed by the electrode arrangement. The electrode arrangements in Figures 11A-B comprise a series of axially aligned electrode strips positioned adjacent to electrode strips of opposite polarity. In such an embodiment, the aerosol-forming matrix 110 is not directly positioned between the opposing electrodes, but is still heated by the presence of an alternating electric field in its vicinity. Stronger and more uniform heating of the aerosol-forming matrix 110 can be achieved using the electrode arrangement shown in Figure 11B, which is configured such that the electric field across the aerosol-forming matrix 110 between the opposing polarity electrodes is strongest. Figures 11C-D illustrate how multiple electrode portions from the electrode arrangements of Figures 11A-B can be electrically connected to achieve an interdigitated configuration.

[0311] Figures 12a-c illustrate alternative electrode arrangements for dielectrically heating a liquid aerosol forming matrix, serving as both a heater assembly and a wicking element. The arrangement in Figure 12a includes a reservoir containing the liquid aerosol forming matrix 110 and multiple electrode plates positioned adjacent to electrode plates of opposite polarity. This arrangement functions by dielectrically heating the liquid aerosol forming matrix located between adjacent electrodes through an alternating electric field generated across the adjacent electrode plates. The distance between adjacent electrode plates can be selected such that the channel between adjacent electrode plates has a capillary effect that draws the liquid aerosol forming matrix into the channel. Figures 12b-c illustrate similar electrode arrangements using an array of interlocking electrode needles instead of electrode plates. Blades, tabs, strips, or cylinders can also be used instead of needles. As better seen in Figure 12c, the interlocking electrode needle array is configured such that adjacent electrode needles have opposite polarities. Such electrode arrangements are particularly suitable for providing uniform heating of the aerosol forming matrix and avoiding localized overheating of the aerosol forming matrix, which can lead to the formation of poor-quality aerosols. Similar to the embodiment in Figure 12a, the distance between adjacent electrode needles in the electrode array can be selected such that the region between adjacent electrode needles has a capillary effect, thereby drawing the liquid aerosol forming matrix into the electrode array.

[0312] Figure 13 is a schematic illustration of a control system utilizing a temperature sensing system to control the power delivered to the aerosol forming matrix 110 based on the detected aerosol forming matrix temperature. The control system includes a controller configured to receive aerosol forming matrix temperature data from the temperature sensing device. If the controller determines that the aerosol forming matrix temperature exceeds a predetermined upper limit threshold, the controller uses a DC / DC cutoff to cut off power to the oscillation circuit, allowing a fixed and variable temperature to be delivered to the aerosol forming matrix.

[0313] In an alternative embodiment, the controller may be configured to use pulse width modulation (PWM) to change the switching duty cycle of the oscillating circuit pulses based on the measured or estimated temperature.

[0314] As an alternative to cutting off the power supply to the oscillating circuit, the bias voltage of the switching unit can be manipulated to keep the transistor outside the oscillation range. The bias voltage or DC voltage, or the DC supply voltage, can be increased or decreased to increase or decrease the voltage delivered to the load capacitor C. L The heating power is adjusted until the measured temperature of the aerosol-forming matrix reaches the target temperature or is within the target temperature range.

[0315] In an alternative embodiment, the feedback loop of the oscillating circuit can be interrupted, for example, by electrical or mechanical means.

[0316] In some embodiments, the control system is configured to control the power delivered to the aerosol-forming matrix in two phases: a first phase in which the temperature of the aerosol-forming matrix rises slowly as quickly as possible (referred to as the warming phase or preheating phase), and a second phase in which the aerosol-forming matrix is ​​maintained at the target aerosolization temperature (referred to as the target heating phase).

[0317] The first stage is performed by maximizing the DC power supply voltage to, for example, 10V to 12V. Once the target aerosolization temperature is reached, for example, between 80°C and 365°C, preferably between 180°C and 320°C, and more preferably between 180°C and 220°C, the heating power is reduced by lowering the power supply voltage to, for example, a lower value of approximately 6.4V to 7.6V. During the gradual rise time of the first stage of temperature control, the total power consumption can be 10W-15W, preferably with an efficiency of at least 65%, and the temperature can be controlled to 180°C-220°C upon reaching the aerosolization temperature of the aerosol forming agent, for example, to achieve constant aerosol delivery over a given process duration.

[0318] During the aerosolization of the aerosol-forming matrix, the DC power supply current typically changes because the dielectric constant of the aerosol-forming matrix decreases. Therefore, the dielectric constant can be used as a value to indicate the temperature of the aerosol-forming matrix.

[0319] In some embodiments, an artificial intelligence network is used to determine the temperature of the aerosol-forming matrix based on one or more of the heating chamber temperature, DC power supply voltage, or DC power supply current.

[0320] Figure 14 shows a block diagram of a control system utilizing a power sensing system for controlling the power delivered to the aerosol forming matrix 110 based on detected power consumption values ​​(DC power supply current, DC power supply voltage, or both). In some instances, the microprocessor 2030 may further receive a temperature signal from the resonant circuit 272. Specifically, this figure illustrates the self-oscillating circuit of Figure 3A in an exemplary application environment. A power supply 2020 supplies power to the oscillating circuit and is connected to the switching unit 260, particularly via a DC / DC converter 2010. The microprocessor 2030 receives signals indicating power, current, and / or voltage provided by the DC / DC converter 2010 or the power supply 2020. In one example, the power sensing system includes a shunt connected between the switching unit 260 and the power supply 2020 (power source), particularly between the switching unit 260 and the DC / DC converter 2010, to derive a voltage indicating the DC power supply current. In some instances, the power sensing system also includes a voltage sensor to measure the voltage across the shunt and feed the result, indicating the DC power supply current, to the microprocessor 2030. The microprocessor 2030 outputs control signals to the DC / DC converter 2010.

[0321] When the controller determines that the aerosol-forming matrix is ​​depleted, it disables the heating operation. For example, the controller uses a DC / DC cutoff to disconnect power to the oscillation circuit, preventing further power supply to the oscillation circuit and causing its amplitude to decrease slowly, thereby causing the temperature delivered to the aerosol-forming matrix to drop continuously. Alternatively, the bias voltage can be shifted to place the switching unit 260 outside the range where the bias or DC voltage oscillates, or the DC power supply voltage can be increased or decreased to thereby reduce the load capacitor C. L The heating power at that point. As an alternative, it would be possible to disable the resonant feedback loop FL by means of electrical or mechanical methods. For example, the circuit could be mechanically interrupted, magnetized, etc.

[0322] Figure 15 is a more detailed block diagram of a control system that utilizes a power sensing system to determine a depletion level according to an embodiment of the present disclosure. The microprocessor 2030 can use the determined depletion level DL to enable heating operation only when the depletion level DL is below a threshold. As used in the embodiments, the threshold indicates the maximum depletion level at which the aerosol-forming matrix is ​​depleted. The minimum depletion level (approximately DL = 0%) indicates the initial state of the aerosol-forming matrix 110, i.e., before the matrix is ​​heated.

[0323] Typically, when an aerosol-forming matrix, for example, comprising tobacco-based materials and aerosol-forming materials, is subjected to heating, the load capacitor C of the aerosol-forming matrix is ​​maintained. LThe dielectric constant will decrease. This is because tobacco materials have a lower dielectric constant compared to, conversely, liquid or gel-like aerosol-forming materials (e.g., a mixture between polypropylene glycol (PPG) and glycerol), and liquid or gel-like aerosol-forming materials will evaporate or aerosolize. PPG has a dielectric constant of 14-20, while glycerol has a dielectric constant of 42.5. Heating and depletion of the aerosol-forming matrix cause a decrease in dielectric constant and therefore, a decrease in the load capacitance C. L The change in resonant frequency caused by the decrease in capacitance, because of the load capacitor C L It is the part of the resonant circuit that oscillates at the resonant frequency.

[0324] The frequency change measured from complete matrix consumption to the maximum depletion level is between 3% and 25%, preferably between 5% and 20%, and particularly between 7% and 15%. This can be increased by using liquid fillers or aerosolizers or materials (e.g., water, PPG, glycerol) with significantly higher dielectric constants than tobacco materials in the matrix.

[0325] In particular, the increase in the dissipation level DL and the resonant frequency indicates a decrease in the dielectric constant of the matrix and thus a decrease in the capacity of the dielectric heating element due to the decrease in the proportion of aerosol forming material.

[0326] The change in resonant frequency is then related to the load capacitor C. L The power loss is proportional to the amount of electricity consumed. Therefore, it is possible to measure power consumption to provide an indication of the reduction in the matrix. In this regard, it is possible (e.g., at the plant level) to simply use a frequency sensor for calibration purposes to correlate different power consumption patterns (e.g., the DC power supply current fed from the power supply of the calibration device) with the oscillation frequency. Subsequently, the aerosol generating device itself may no longer need to have a frequency sensor or frequency sensing system.

[0327] Therefore, based on the previously performed frequency measurements and calibrations, a mapping function MF as shown in Figure 15 can be generated and pre-stored at the aerosol generation device, making it possible to use power consumption values ​​(DC power supply current, DC power supply voltage, or both) as parameters indicating matrix depletion.

[0328] Figure 16 is a schematic illustration of a control system utilizing a frequency sensing system according to an embodiment of the present disclosure, the control system being used to control the power delivered to an aerosol-forming matrix based on the frequency of an alternating electric field detected across an electrode assembly. The system includes a resonant cavity (or resonator, e.g., a quarter-wavelength resonator) having a peak resonant frequency higher than the switching frequency of the oscillating feedback loop. The resonant cavity is fabricated, for example, by using impurities or mechanical defects to provide a wide range of frequency responses exhibiting variation between different frequencies, such that the operating range of frequencies is covered by the resonant response. In one embodiment, the resonator includes a quarter-wavelength coaxial cavity resonator with an inner conductor. The resonator includes an insulator doped with impurities. The resonator is located within a load capacitor C. L At a location within the generated electric field, for example, at the load capacitor C L The outer area or the area of ​​the heating chamber that will not obstruct the formation of the aerosol matrix.

[0329] The resonator is connected to the rectifier via a direct electrical coupler to generate a DC signal. The generated DC signal is fed to a resistor / impedance for measurement by a voltage measuring device. The voltage measurement is transmitted to a controller / microprocessor for calibration / further processing. In particular, the system can be used as a calibration system to generate the mapping function MF as discussed with respect to Figure 15.

[0330] In an alternative embodiment, the system may utilize one or more of a resonant antenna, microstrip, and waveguide for high-frequency sensing.

[0331] Figure 18 is a schematic illustration of a control system that uses a power sensing system to determine the dissipation level DL based on the frequency of the alternating electric field detected across the electrode assembly, according to an embodiment of the present disclosure.

[0332] Compared to the embodiment discussed with respect to Figure 15, the system includes a frequency detection unit FD to derive the frequency from the load capacitor C. L The frequency of the alternating electric field is generated and detected by the power sensing system. The derived frequency is then fed into a pre-stored mapping function MF, which maps the derived frequency, in particular the resonant frequency of the oscillator circuit 150, to the dissipation level DL.

[0333] The microprocessor 2030 can use a determined depletion level DL to enable heating operation only when the depletion level DL is below a threshold. As used in the embodiments, the threshold indicates the maximum depletion level at which the aerosol-forming matrix is ​​depleted. The minimum depletion level (approximately DL = 0%) indicates the initial state of the aerosol-forming matrix 110, i.e., before the matrix is ​​subjected to heating.

[0334] The system can utilize one or more of the following for high-frequency sensing: resonant antenna, microstrip, and waveguide.

[0335] It should be understood that the embodiments described above are merely exemplary embodiments, and various other embodiments according to this disclosure are also conceivable.

[0336] Figure 19 is a schematic illustration of a method for dielectrically heating an aerosol forming matrix 110 according to an embodiment of the present disclosure. The method is performed in an exemplary application environment by an aerosol generating apparatus 120 having the self-oscillating circuit of Figure 3A and the control system of Figure 14. However, the method is not limited to using the control system of Figure 14. In an alternative embodiment, the control system of Figure 15 may be used instead. The method includes the following steps: in a first step, power, particularly DC power, is supplied from a power supply device 2020 (power supply) to an oscillating circuit 150 of the aerosol generating apparatus 120, the oscillating circuit 150 including a switching unit 260, and a feedback loop 270 of the oscillating circuit 150 including a load capacitor C arranged for heating the aerosol forming matrix 110. L (Dielectric heating element).

[0337] In the second step, the load capacitor C is measured. L The electrical parameters associated with the capacitance and based on said electrical parameters.

[0338] In the third step, the properties of the aerosol-forming matrix 110 are determined. In this example, electrical parameters include power consumption values ​​drawn from the power supply device 2020 and measured as explained with respect to Figure 14, specifically the DC power supply current. The determined properties of the matrix include the dissipation level DL of the aerosol-forming matrix 110, which is determined by mapping the measured DC power supply current (or power consumption value, or DC power supply voltage, or DC voltage at the DC / DC converter 2010) to the dissipation level using the mapping function MF shown in Figure 15. In an alternative example, the dissipation level is determined by mapping the load capacitor C across the load capacitor C using the mapping function MF shown in Figure 18. L The frequency of the alternating electric field detected by the electrodes (see Figure 16) is mapped to the dissipation level to determine the method.

[0339] In the fourth step, the aerosol generating device 120 performs actions based on the determined properties of the matrix. When the depletion level exceeds a threshold indicating that the aerosol forming matrix 110 is nearly empty, the actions may include at least one of shutting off heating, slowing down heating, and instructing the user that the aerosol forming matrix 110 is considered empty.

[0340] For the purposes of this specification and the appended claims, unless otherwise stated, all figures representing quantities, quantities, percentages, etc., should be understood to be modified by the term "about" in all cases. Furthermore, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges that may or may not be specifically listed herein. Therefore, in this context, the figure A is understood to be 5% of A ± A.

Claims

1. An aerosol generating apparatus for dielectrically heating an aerosol-forming matrix of an aerosol-forming article, the aerosol generating apparatus comprising: power supply; And an oscillation circuit, the oscillation circuit comprising: a switching unit; a resonant oscillation feedback circuit connected between the input and output of the switching unit, the resonant oscillation feedback circuit including a dielectric heating element arranged for dielectrically heating the substrate; wherein, in operation, electrical parameters associated with the capacitance of the dielectric heating element are measured to determine the properties of the substrate.

2. The aerosol generating apparatus according to the preceding claim, wherein the aerosol generating apparatus further comprises a power sensing system for detecting a power consumption value drawn from the power source, wherein the power consumption value is used as the electrical parameter associated with the capacitance of the dielectric heating element.

3. The aerosol generating apparatus according to claim 2, wherein the power consumption value indicates the power supply current drawn from the power source, particularly the DC power supply current.

4. The aerosol generating apparatus according to any one of the preceding claims, wherein the oscillation frequency of the oscillation circuit is in the range of 10 MHz to 100 GHz, preferably between 100 MHz and 1.5 GHz, and particularly between 200 MHz and 900 MHz.

5. The aerosol generating apparatus according to any one of the preceding claims, wherein the electrical parameter is a value indicating the relative permittivity of the material forming the matrix, and wherein the determined properties of the matrix include the attenuation of the matrix, wherein the aerosol generating apparatus further comprises a data processor, wherein the data processor is configured to determine the attenuation level of the matrix based on a relationship with the oscillation frequency of the oscillation circuit.

6. The aerosol generating apparatus according to the preceding claim, wherein the frequency variation from complete matrix consumption to the maximum depletion level is between 3% and 25%, preferably between 5% and 20%, and particularly between 7% and 15%.

7. The aerosol generating apparatus according to claim 5 or claim 6, wherein the relationship includes a mapping function MF that maps parameters associated with the oscillation frequency of the oscillation circuit to a predefined or predetermined attenuation level.

8. The aerosol generating apparatus according to the preceding claim, wherein the parameters include a power consumption value, preferably a DC power supply current drawn from the power source.

9. A system comprising: Aerosol-generating products, including aerosol-forming matrices; And an aerosol generating apparatus according to any one of the preceding claims for electrically heating the aerosol forming matrix.

10. The system according to the preceding claim, wherein the aerosol forming matrix comprises a solid material.

11. A method for electrically heating an aerosol-forming matrix of an aerosol-forming article using an aerosol generating apparatus, the method comprising the following steps: Power is supplied from a power source to an oscillating circuit of the aerosol generating device. The oscillating circuit includes: a switching unit; a resonant oscillation feedback circuit connected between the input and output of the switching unit, the resonant oscillation feedback circuit including a dielectric heating element arranged for heating the matrix; and measuring electrical parameters associated with the capacitance of the dielectric heating element to determine the properties of the matrix.

12. The method according to the preceding claim further comprises determining the properties of the matrix, wherein the determination includes mapping measured electrical parameters to the properties of the matrix by means of a mapping function preferably pre-stored on the aerosol generating device, and wherein the electrical parameters include a power consumption value drawn from the power source, preferably a DC power supply current, and wherein the determined properties of the matrix include the level of depletion of the matrix.

13. A method for calibrating an aerosol generating device, the method comprising the following steps: Power is supplied from a power source to an oscillating circuit of the aerosol generating apparatus. The oscillating circuit includes a switching unit and a resonant oscillation feedback circuit, which includes two opposing electrodes for heating an aerosol forming matrix, wherein the matrix is ​​located between the two opposing electrodes. The frequency of the electric field between the electrodes is measured, the measured frequency is correlated with the supplied power, and the obtained relationship is stored in a mapping function of the aerosol generating apparatus.

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