High-frequency household appliance, preferably high-frequency kitchen appliance

Abstract

The invention relates to a high-frequency household appliance (1), preferably a high-frequency kitchen appliance (1), with at least one treatment chamber (11) configured to receive material to be treated with high-frequency energy, and with at least one high-frequency heating module (2) configured to generate the high-frequency energy and deliver it to the treatment chamber (11), wherein the high-frequency heating module (2) comprises at least: • at least one high-frequency signal generator (21) configured to generate the high-frequency energy, and • at least one interface (ANT) to the treatment chamber (11) of a first high-frequency path (23a-23d), preferably one interface (ANT) each to the treatment chamber (11) of several high-frequency paths (23a-23d), which is configured to deliver high-frequency energy to the treatment chamber (11). The high-frequency household appliance (1) is characterized in that the high-frequency heating module (2),preferably at least the first high-frequency path (23a-23d), more preferably several high-frequency paths (23a-23d), and most preferably all high-frequency paths (23a-23d) of the high-frequency heating module (2), further comprising at least: • at least one measuring circuit (UIM, FDIV, ADC) configured to detect at least one parameter of the high-frequency energy, and • at least one safety unit (22) configured to receive the at least one detected parameter from the measuring circuit (UIM, FDIV, ADC) and to evaluate it with regard to compliance with at least one predetermined limit value, wherein the high-frequency heating module (2), preferably the safety unit (22), is configured to operate the high-frequency signal generator (21) depending on the evaluation of the parameter, and preferably to switch off the high-frequency signal generator (21) when a predetermined limit value of the parameter is exceeded.

Description

[0001] The invention relates to a high-frequency household appliance according to the preamble of claim 1.

[0002] It is well known that materials can be heated using microwaves. Microwaves are electromagnetic waves with a frequency of approximately 1 to 300 GHz, meaning wavelengths of approximately 30 cm to 1 mm. Microwaves can cause molecules to vibrate, thereby increasing their temperature. This is used, for example, in microwave ovens to heat or cook food inside the cooking chamber.

[0003] A microwave oven, also called a microwave cooker, typically has an outer casing containing a cooking chamber. The cooking chamber is accessible from the outside through an opening, which can be opened and closed, for example, by means of a hinged door or flap. Display and control elements are also usually provided on the outside, allowing the user to adjust settings such as power and cooking time. A space is formed between the outer casing and the cooking chamber, in which at least one microwave generator is typically located. This generator produces the microwaves and transmits them into the cooking chamber via at least one high-frequency waveguide. While magnetrons were originally used to generate the microwave radiation, electronic circuits such as transistors are now commonly used for this purpose.It is generally known to use a coaxial cable with appropriate coaxial connectors between the RF module (radio frequency module), which acts as a microwave generator, and the cooking chamber of the microwave oven to transmit the RF energy to the interior. The coaxial cable can be integrated with an antenna, i.e., without any additional connectors, and mounted on the interior wall. The antenna can be, for example, a monopole antenna or an inverted F-shaped antenna.

[0004] The RF energy can also be guided into the interior via an RF waveguide (high-frequency waveguide). Typical cross-sections of waveguides can be rectangular or oval, for example. The RF waves travel vertically along such waveguides in the interior wall and pass through, for example, a rectangular or oval window in the wall, thus entering the interior.

[0005] The applicant also discloses a type of kitchen appliance known as a "dialogue oven." A dialogue oven is based on conventional ovens that operate using energy sources such as top and bottom heat or convection, allowing precisely controlled heat to penetrate the food from the outside and slowly work its way into the center. This cooking method, similar to baking, results in the outer layers of the food being heated for a relatively long time and at a high temperature, while the core of the food is heated for a relatively short time and at a lower temperature, as the heat must first spread from the outer layers to the center of the food during the cooking process.

[0006] To accelerate such cooking processes and / or distribute the heat more evenly within the food, conventional ovens have been further developed into the Dialog oven. This oven additionally utilizes electromagnetic waves with varying frequencies in the high-frequency spectrum (HF waves) to heat only the food itself and not its surroundings or the ambient air. This allows for very precise control over the amount of heat applied to the food. This can lead to significantly faster cooking times and improved quality of the final product.

[0007] Devices for supplying high-frequency energy (RF energy) to the operating chamber of a household or kitchen appliance provide a separate RF signal generator for each path or input. This makes it possible to generate RF signals for the paths at different frequencies, which can be desirable for certain heating methods or programs.

[0008] The use of high-frequency energy in the form of electromagnetic waves in appropriate household appliances can offer advantages for their intended use.

[0009] However, such electromagnetic waves of high-frequency energy can pose a risk to the environment surrounding the high-frequency household appliance. They can interfere with other electronic devices. Furthermore, they can endanger the health of living beings, and especially the user of the high-frequency household appliance.

[0010] EP 2 499 505 A1 describes devices and methods for applying electromagnetic energy to a load. The devices and methods can include at least one processor configured to receive information specifying the energy derived from the load for each of a plurality of modulation space elements. The processor can also be configured to associate each of the multiple modulation space elements with a corresponding duration of power application based on the received information. Furthermore, the processor can be configured to control the energy applied to the load such that, for each of the multiple modulation space elements, power is applied to the load for the corresponding duration of power application.

[0011] US 2015 / 271877 A1 discloses a high-frequency household appliance according to the preamble of claim 1.

[0012] The invention thus addresses the problem of creating a high-frequency household appliance of the type described above, such that the protection of the environment from electromagnetic waves of high-frequency energy can be improved or even guaranteed. In particular, the propagation of impermissibly strong high-frequency energy and / or high-frequency energy of impermissible frequencies into the vicinity of the high-frequency household appliance should be reduced or even completely prevented. In particular, compliance with radio frequency and EMC limits should be ensured. This is intended especially for high-frequency kitchen appliances. At the very least, an alternative to known high-frequency household appliances of this type should be created. According to the invention, this problem is solved by a high-frequency household appliance with the features of claim 1. Advantageous embodiments and further developments of the invention are described in the following dependent claims.Thus, the invention relates to a high-frequency household appliance, preferably a high-frequency kitchen appliance, with at least one treatment chamber which is designed to receive a material to be treated with high-frequency energy, and with at least one high-frequency heating module which is designed to generate the high-frequency energy and deliver it into the treatment chamber, wherein the high-frequency heating module comprises at least: . at least one high-frequency signal generator configured to generate high-frequency energy, and at least one transition to the treatment space of a first high-frequency path, preferably one transition to the treatment space of several high-frequency paths, configured to deliver high-frequency energy into the treatment space.

[0013] Such a high-frequency household appliance can be any technical device that can be used in a household for household tasks, whereby the household task can be performed additionally or exclusively by means of high-frequency (HF) energy. The high-frequency energy can be emitted into the treatment room by means of electromagnetic waves to warm or heat the object being treated. Such high-frequency electromagnetic waves can, in particular, have frequencies in the range of approximately 1 to approximately 300 GHz, i.e., wavelengths of approximately 30 cm to approximately 1 mm.

[0014] The implementation can take the form of a household appliance, such as a washing machine, tumble dryer, washer-dryer, or similar device, allowing the high-frequency energy to be used additionally or exclusively for heating water or washing solution, or for drying wet laundry within the washing drum as a treatment chamber. In a high-frequency kitchen appliance, the high-frequency energy can be used additionally or exclusively for cooking food within the cooking chamber as a treatment chamber. Examples of such kitchen appliances include microwave ovens, conventional ovens, combination ovens, or similar appliances.

[0015] Furthermore, the high-frequency heating module, preferably at least the first high-frequency path, particularly preferably several high-frequency paths, most preferably all high-frequency paths, of the high-frequency heating module, further comprises at least: at least one measuring circuit configured to detect at least one parameter of the high-frequency energy, and at least one safety unit configured to receive the at least one detected parameter from the measuring circuit and with regard to the

[0016] to evaluate compliance with at least one predetermined limit value, wherein the high-frequency heating module, preferably the safety unit, is configured to operate the high-frequency signal generator depending on the evaluation of the parameter, preferably to switch off the high-frequency signal generator when a predetermined limit value of the parameter is exceeded.

[0017] According to the invention, high-frequency energy or its electromagnetic wave can be monitored in this way before it is emitted or transmitted into the treatment room via the respective interface. For example, an impermissible frequency of the high-frequency energy can be detected and its propagation into the treatment room prevented. This can serve to protect the environment and, in particular, to ensure compliance with radio frequency and EMC limits.

[0018] To achieve this and to prevent the propagation of high-frequency energy into the treatment room with undesirable or even impermissible characteristics, at least one parameter of the high-frequency energy is detected or determined and evaluated with regard to the fulfillment of criteria or compliance with limit values, as will be described in more detail below using preferred variants. In any case, the safety unit can perform an evaluation of the at least one detected parameter to determine whether this parameter complies with at least one predetermined limit value or fulfills a predetermined criterion. This limit value, or several limit values ​​of one parameter, or one limit value, or several limit values ​​of different parameters, and / or the criterion, or several criteria, can be...can enable an assessment of whether the high-frequency energy, after exiting the treatment room, is desirable or permissible with regard to the corresponding parameter or criterion.

[0019] If an undesired or impermissible characteristic of the high-frequency energy or its electromagnetic wave is detected in this way, the high-frequency heating module, and in particular its safety unit, can react accordingly and modify the operation of the high-frequency signal generator. Specifically, the generation of the undesired or impermissible high-frequency energy or its electromagnetic wave by the high-frequency signal generator can then be prevented. In any case, this can be indicated or communicated to the user in order to carry out or arrange for repair of the high-frequency household appliance. According to the invention, this can improve or even guarantee the protection of the environment from electromagnetic waves of high-frequency energy. In particular, the propagation of impermissibly strong high-frequency energy and / or its electromagnetic wave can be prevented.or high-frequency energy of impermissible frequency into the vicinity of the high-frequency household appliance is reduced or even completely avoided.

[0020] The high-frequency household appliance according to the invention is characterized in that the measuring circuit is designed as a voltage / current measuring circuit to detect the voltage and current of the high-frequency energy, preferably of a high-frequency power amplifier, and the safety unit is designed to obtain the detected voltage and current from the voltage / current measuring circuit, to determine a DC power consumption from this, and to evaluate the determined DC power consumption with regard to compliance with a predetermined limit value. This can represent one way of implementing the aspects of the present invention described above.

[0021] According to one aspect of the invention, the predetermined limit value is based on at least one current operating parameter, preferably the amplitude and / or frequency of the high-frequency energy of the high-frequency heating module, preferably of the high-frequency signal generator. According to the invention, this allows for verification as to whether, during the propagation path of the high-frequency energy generated by the high-frequency signal generator to the treatment room or to a specific point within the propagation path, the high-frequency energy still corresponds to the desired characteristics, or whether an undesired or impermissible change has occurred due to electronic components along the propagation path. This also applies to the high-frequency signal generator itself. In any case, this could be caused by defective electronic components or their incorrect parameterization.

[0022] According to a further aspect of the invention, at least the first high-frequency path, preferably several high-frequency paths, and particularly preferably all high-frequency paths, further comprises at least one high-frequency coupler configured to measure the power of a forward-propagating high-frequency wave of the emitted high-frequency energy, and the safety unit configured to determine an efficiency from the determined DC power consumption and the detected power of the forward-propagating high-frequency wave, and to evaluate the determined efficiency with regard to compliance with a predetermined limit value. This can represent an alternative way of implementing the previously described aspects of the present invention.

[0023] According to a further aspect, which is not part of the claimed invention, the measuring circuit is configured as a frequency divider to detect the frequency of the high-frequency energy, preferably from a high-frequency power amplifier, and the safety unit is configured to obtain the frequency from the frequency divider and evaluate it with regard to compliance with a predetermined limit value, wherein the predetermined limit value is preferably based on the current frequency of the high-frequency signal generator. This can represent an alternative way of implementing the previously described aspects of the present invention.

[0024] According to a further aspect, which is not part of the claimed invention, the measuring circuit is configured as a sampling converter to detect a high-frequency signal sample of the high-frequency energy, preferably from a high-frequency power amplifier, and the safety unit is configured to receive the high-frequency signal sample from the sampling converter and to evaluate it with regard to compliance with at least one predetermined criterion, preferably with regard to compliance with several predetermined criteria, wherein the measuring circuit preferably comprises a high-frequency synthesizer and a high-frequency mixer. This can represent an alternative way of implementing the aspects of the present invention described above.

[0025] According to a further aspect of the invention, at least one high-frequency path, preferably several high-frequency paths, and especially preferably all high-frequency paths, further comprises: at least one first bandpass filter, which is designed to allow only a predetermined frequency range of the high-frequency energy to pass through.

[0026] This allows the frequency range of the high-frequency electromagnetic wave of the corresponding high-frequency path to be limited to a predetermined frequency range.

[0027] According to a further aspect of the invention, at least one high-frequency path, preferably several high-frequency paths, and particularly preferably all high-frequency paths, further comprises at least one second bandpass filter, which is redundant to the first bandpass filter, wherein the second bandpass filter is preferably arranged downstream, and particularly preferably directly downstream, of a phase shifter. The second bandpass filter serves as a safety feature to take over the function of the first bandpass filter if the first bandpass filter malfunctions. This can improve the protection of the environment from undesirable or impermissible characteristics of the high-frequency energy or its electromagnetic wave.

[0028] According to one aspect of the invention, at least the first high-frequency path, preferably several high-frequency paths, and especially preferably all high-frequency paths, further comprises: at least one high-frequency power amplifier, preferably also at least one high-frequency preamplifier, which is designed to amplify the high-frequency energy.

[0029] This allows for power amplification of the high-frequency electromagnetic wave within the high-frequency path or within the high-frequency feed point. This can be done in a single stage or in multiple stages to achieve higher power levels.

[0030] According to a further aspect of the invention, at least the first high-frequency path, preferably several high-frequency paths, and especially preferably all high-frequency paths, further comprises: at least one high-frequency coupler designed to measure a forward-propagating and / or a backward-propagating high-frequency wave of the emitted high-frequency energy, preferably no amplifier is arranged between the high-frequency coupler and the transition.

[0031] In this way, a forward-propagating and / or a reverse-propagating high-frequency wave of the emitted high-frequency energy can be detected, and the detected data can be evaluated to, for example, influence the generation of the high-frequency electromagnetic wave by the high-frequency signal generator and / or other electronic components within the respective high-frequency path. This can increase the design flexibility of the high-frequency electromagnetic wave emitted into the treatment room. Such a high-frequency coupler can be configured, for example, as a 4-port coupler or a 6-port coupler.

[0032] According to a further aspect of the invention, at least the first high-frequency path, preferably several high-frequency paths, and especially preferably all high-frequency paths, further comprises: at least one damping element designed to change the amplitude of the high-frequency energy.

[0033] This allows targeted influence to be exerted on the amplitude of the high-frequency electromagnetic wave along the corresponding high-frequency path.

[0034] According to a further aspect of the invention, at least the first high-frequency path, preferably several high-frequency paths, and especially preferably all high-frequency paths, further comprises: at least one phase shifter designed to change the phase of the high-frequency energy.

[0035] This allows targeted influence to be exerted on the phase of the high-frequency electromagnetic wave along the corresponding high-frequency path.

[0036] According to a further aspect of the invention, at least the first high-frequency path, preferably several high-frequency paths, and especially preferably all high-frequency paths, further comprises: at least one high-frequency insulator designed to block a reverse-propagating high-frequency wave of the emitted high-frequency energy, preferably no amplifier is arranged between the high-frequency isolator and the transition.

[0037] Such a high-frequency isolator can be implemented, for example, using a high-frequency circulator with a high-frequency load resistor. In any case, this protects the electronic components of the corresponding high-frequency path from powerful, reverse-propagating high-frequency waves of the emitted high-frequency energy, thus preventing damage or destruction of the electronic components.

[0038] According to a further aspect of the invention, at least the first high-frequency path, preferably several high-frequency paths, and especially preferably all high-frequency paths, further comprises: at least one harmonic filter designed to block harmonics in a forward-propagating wave of high-frequency energy, preferably no amplifier is arranged between the harmonic filter and the transition.

[0039] This prevents corresponding harmonics in the forward-propagating high-frequency wave of the emitted high-frequency energy.

[0040] According to a further aspect of the invention, the high-frequency heating module has at least one control unit which is designed to to obtain measurement data of a forward-propagating and / or a backward-propagating high-frequency wave of the emitted high-frequency energy, preferably from a high-frequency coupler, and to determine at least an amplitude and / or a phase of a forward-propagating and / or a backward-propagating high-frequency wave of the emitted high-frequency energy from the obtained measurement data.

[0041] The acquisition of the corresponding measurement data can be carried out, for example, using the previously described high-frequency coupler, which may include circuits such as ADCs (Analog Digital Converters) and the like.

[0042] In any case, this method allows for a corresponding influence on the forward-propagating high-frequency wave of the emitted high-frequency energy. Since the amplitude and phase of a high-frequency wave propagating forward and backward at the high-frequency coupler of the respective high-frequency path depend on the high-frequency wave fields in the treatment chamber, these measurement data contain information about the contents of the treatment chamber (e.g., food), the high-frequency wave fields, and the high-frequency energy supply. This information can be used by the heating programs of the control unit to control the frequency of the high-frequency signal generator and, if applicable, the actuators of the respective high-frequency path, such as attenuators and / or phase shifters, thus advantageously regulating the high-frequency energy supply.According to a further aspect of the invention, the control unit is further configured to operate at least the high-frequency signal generator, preferably also at least one attenuator and / or a phase shifter of at least one high-frequency path, preferably several high-frequency paths, and particularly preferably all high-frequency paths, depending on the specific amplitude and / or the specific phase, preferably to change the frequency of the high-frequency energy. This allows a corresponding influence to be exerted on the forward-propagating high-frequency wave of the emitted high-frequency energy.

[0043] A further disclosure is made of a high-frequency heating module, which is not part of the claimed invention, for use in a high-frequency household appliance as described above. This makes it possible to provide a high-frequency heating module for realizing a high-frequency household appliance according to the invention and to utilize its properties and advantages.

[0044] In other words, according to the invention an RF heating module is created in whose RF power amplifiers voltage and / or current measurement circuits (UIM) can be arranged, which enable measurement and monitoring of the DC power consumption(s) of the RF power amplifiers during operation.

[0045] During operation, a safety microcontroller (uC) can regularly measure the DC power consumption (P_DC) of the RF power amplifiers for each path and compare it with DC power consumption values ​​that should be present based on the current operating parameters, such as the amplitude and frequency of the RF signal. If deviations between these values ​​exceed predetermined limits, the safety uC can stop RF generation.

[0046] This prevents the risk of the RF power amplifier entering a self-oscillation state (e.g., due to a component defect), which could generate a strong RF signal at a frequency outside the permissible range. A strong RF wave with the wrong frequency could then enter the treatment room. Since the microwave trap at the treatment room door is typically designed for only a permissible frequency range, an unacceptably high amount of RF energy could escape from the device, potentially exceeding the permissible limits for RF fields.

[0047] However, according to the invention, this situation can be prevented by utilizing the fact that the DC power consumption during self-oscillation deviates significantly from the DC power consumption values ​​that would be expected based on the current operating parameters, such as, in particular, the amplitude and frequency of the RF signal. Such a deviation can be detected as described, and RF generation can be stopped in this case.

[0048] The measurement of DC power consumption values ​​can be simplified to measuring DC current consumption values ​​and assuming known or less frequently or precisely measured DC voltage values.

[0049] Alternatively, according to the invention, the respective powers of the forward-propagating RF waves (P_FWD) of each path can also be determined using RF couplers. This allows an efficiency (EFF) to be calculated for each path from the ratio of P_FWD to P_DC. In this case, the safety microcontroller (uC) can regularly determine the efficiency (EFF) for each path during operation and compare it with efficiency values ​​that should be given based on the current operating parameters, such as P_DC. If deviations between these values ​​exceed predetermined limits, the safety microcontroller can also stop RF generation.

[0050] This also avoids the previously described danger, as the efficiency during self-oscillation deviates significantly from the efficiency values ​​that should be given based on the current operating parameters, such as P_DC. Such a deviation can be detected as described, and RF generation can be stopped in this case as well.

[0051] The circuits on the RF couplers can be designed using filters so that they are relatively effective or sensitive in the permissible RF range and relatively ineffective or insensitive in the impermissible RF range.

[0052] Alternatively, according to the invention, an RF frequency divider can be arranged which divides down the frequency of a signal sample coupled out behind the RF power amplifiers.

[0053] In this case, the safety microcontroller can regularly measure the frequency of the downsampled signal during operation and compare it with the frequency that should be present based on the current setting of the RF signal generator. If deviations between these values ​​exceed predetermined limits, the safety microcontroller can stop RF generation.

[0054] Similarly, the safety microcontroller can regularly measure the period of the divided signal during operation and compare it with the period that should be present based on the frequency currently set on the RF signal generator. If deviations between these values ​​exceed predetermined limits, the safety microcontroller can also stop the RF generation.

[0055] This also prevents the previously described danger, since the frequency or period of the divided signal deviates noticeably from the frequency or period value that should be present based on the frequency currently set on the RF signal generator during self-oscillation. Such a deviation can be detected as described, and RF generation can be stopped in this case.

[0056] Optionally, a frequency-to-voltage converter can be arranged instead of or in addition to the frequency divider.

[0057] Alternatively, according to the invention, an RF converter consisting of an RF synthesizer and an RF mixer can be arranged for monitoring RF generation during operation. This converter downmixes an RF signal sample coupled out after the RF power amplifiers to an intermediate frequency (IF) range. A sampler enables the safety microcontroller (uC) to sample and analyze the IF signal sample. The safety microcontroller can set the RF synthesizer to a frequency within a relatively large RF range, thus enabling the RF conversion of the signal sample to the (relatively small) IF range from a relatively large RF range and, consequently, a successive analysis of a relatively large RF range.

[0058] The safety microcontroller (uC) can now regularly analyze the RF ranges of the signal probe during operation and check them against specific criteria. For example, if a criterion is violated that the signal probe exhibits a level within an expected or plausible range in an RF range permissible for safe operation, the safety uC can stop RF generation. Similarly, if a criterion is met that the signal probe exhibits a level above a threshold in an RF range impermissible for safe operation, the safety uC can also stop RF generation. Finally, if the criterion is violated that the signal probe exhibits a level below a threshold in an RF range impermissible for safe operation, the safety uC will stop RF generation.

[0059] This also prevents the previously described danger, as regular checks of criteria as described above can take place and RF generation can be stopped if necessary.

[0060] Several embodiments of the invention are shown schematically in the drawings and are described in more detail below. It shows Figure 1 is a schematic representation of a high-frequency household appliance according to the invention; Figure 2 is a schematic representation of a high-frequency heating module of the high-frequency household appliance according to a first embodiment; Figure 3 is a schematic representation of a high-frequency heating module of the high-frequency household appliance according to a second embodiment; Figure 4 is a schematic representation of a high-frequency heating module of the high-frequency household appliance according to a third embodiment; and Figure 5 is a schematic representation of a high-frequency heating module of the high-frequency household appliance according to a fourth embodiment.

[0061] A high-frequency household appliance 1 according to the invention is considered using the example of a high-frequency kitchen appliance 1, which can be, for example, a microwave oven 1, a microwave cooker 1, or a Dialog oven 1. The high-frequency kitchen appliance 1 has an outer housing 10, which encloses and protects the components of the high-frequency kitchen appliance 1. Inside the high-frequency kitchen appliance 1, a treatment chamber 11 is provided, which is enclosed or formed by a wall 12. A space 13 is formed between the outer housing 10 and the wall 12 of the treatment chamber 11, which accommodates the electrical and electronic components of the high-frequency kitchen appliance 1. The treatment chamber 11 can be accessed and closed by opening a closure element (not shown), for example, in the form of a door or flap.

[0062] In treatment chamber 11, which can also be referred to as interior space 11, cooking chamber 11, or cavity 11, a cooking process of the high-frequency kitchen appliance 1 can be carried out. For this purpose, with the closure element open, a person (the user) can place food to be cooked or treated into treatment chamber 11 and then close the treatment chamber 11. The cooking process can be carried out solely by the energy of high-frequency electromagnetic waves, as in a microwave oven 1, or additionally, for example, with convection in a Dialog oven 1.

[0063] In any case, the high-frequency energy in the form of high-frequency electromagnetic waves is generated by a high-frequency heating module 2 of the high-frequency kitchen appliance 1, which is essentially located in the space 13. The high-frequency heating module 2 has exactly one high-frequency signal generator 21, which is configured to generate the high-frequency energy for the treatment chamber 11. The high-frequency signal generator 21 is operated by a control unit 20 as a functional microcontroller 20. The generated high-frequency energy is distributed equally to several, for example four, high-frequency paths 23a-23d as high-frequency feeds 23a-23d and delivered to the treatment chamber 11 via the high-frequency paths 23a-23d.Each of the four high-frequency paths 23a-23d has its own transition ANT in the form of an antenna ANT, which extends into treatment room 11 and can thus transmit the respective portion of the high-frequency energy into treatment room 11. This occurs at the frequency at which the high-frequency energy was generated by the high-frequency signal generator 21. Therefore, several high-frequency paths 23a-23d can be implemented with just a single high-frequency signal generator 21.

[0064] The four high-frequency paths 23a-23d are identically designed and each has different electrical or electronic components or assemblies in the following sequence, which modify the high-frequency energy between the high-frequency signal generator 21 and the respective transition ANT to the treatment room 11 and / or possess other properties.

[0065] Each high-frequency path 23a-23d first includes an attenuator PGA, which is configured to change the amplitude of the high-frequency energy. Subsequently, a first bandpass filter BPF is provided for each high-frequency path 23a-23d, which is configured to allow only a predetermined frequency range of the high-frequency energy to pass through. This is followed by a phase shifter PHS, which is configured to change the phase of the high-frequency energy, followed by a second bandpass filter BPF, which is identical to and therefore redundant with the first bandpass filter BPF.

[0066] Next, the high-frequency energy undergoes a two-stage amplification process, first using a high-frequency preamplifier (PRE) and then a high-frequency power amplifier (HPA). This is followed by a high-frequency isolator (ISO), which is designed to block any backward propagation of the output high-frequency energy, thus protecting the high-frequency power amplifier (HPA) and the other preceding electronic components and assemblies.

[0067] A high-frequency coupler (CPL) is then provided, which is designed to measure a forward-propagating and / or a reverse-propagating high-frequency wave of the emitted high-frequency energy. Finally, a harmonic filter (HSF) follows, which is designed to block harmonics in a forward-propagating wave of high-frequency energy.

[0068] Each of the four high-frequency paths 23a-23d has, according to the first embodiment of the Figure 2A voltage / current measurement circuit UIM is also shown as an example of a measurement circuit UIM, FDIV, ADC, which detects the voltage and current of the currently generated high-frequency energy after its exit from the high-frequency power amplifier HPA. The detected voltage and current are transmitted by the voltage / current measurement circuit UIM to a safety unit 22 in the form of a safety microcontroller 22 of the high-frequency heating module 2, which uses this information to determine the DC power consumption of the high-frequency power amplifier HPA. The safety unit 22 also receives the current DC power consumption of the high-frequency signal generator 21, or the corresponding voltage and current values, in order to determine the current DC power consumption of the high-frequency signal generator 21.The safety unit 22 now evaluates the specific DC power consumption with regard to compliance with a predetermined limit value, where this predetermined limit value is the current DC power consumption of the high-frequency signal generator 21.

[0069] If the safety unit 22 detects an exceedance of the predetermined limit value, this is considered impermissible high-frequency energy and the high-frequency signal generator 21 is switched off to protect the environment of the high-frequency kitchen appliance 1 from the impermissible high-frequency energy.

[0070] According to the second embodiment of the Figure 3The existing high-frequency coupler CPL of the high-frequency paths 23a-23d is used to measure the power of a forward-propagating high-frequency wave of the emitted high-frequency energy. The safety unit 22 is configured to determine a current DC power consumption from the detected voltage and current, to determine an efficiency from the determined DC power consumption and the detected power of the forward-propagating high-frequency wave, and to evaluate the determined efficiency with regard to compliance with a predetermined limit value, wherein the predetermined limit value is based on the current DC power consumption of the high-frequency signal generator 21. This may allow for an alternative implementation.

[0071] According to the third embodiment of the Figure 4A frequency divider FDIV is configured as a measuring circuit UIM, FDIV, ADC to detect the frequency of the high-frequency energy at the output of the high-frequency power amplifier HPA. The safety unit 22 is configured to obtain the frequency from the frequency divider FDIV and evaluate it for compliance with a predetermined limit value, where the predetermined limit value is based on the current frequency of the high-frequency signal generator 21. This can enable an alternative implementation.

[0072] According to the fourth embodiment of the Figure 5A sample-and-converter ADC is configured as a measurement circuit UIM, FDIV, ADC to acquire a high-frequency signal sample of the high-frequency energy of the high-frequency power amplifier HPA. The safety unit 22 is configured to receive the high-frequency signal sample from the sample-and-converter ADC and evaluate it for compliance with a predetermined criterion. The measurement circuit UIM, FDIV, ADC also includes a high-frequency synthesizer SYN and a high-frequency mixer MIX. This allows for an alternative implementation. Reference numeral list (part of the description)

[0073] ADC Sampler; Analog-to-Digital Converter ANT Transitions or antennas to the treatment room 11 BPF Bandpass filter CPL High-frequency coupler FDIV Frequency divider HPA High-frequency power amplifier; High-power amplifier HSF Harmonic suppression filter; Harmonic suppression filter ISO High-frequency isolator MIX High-frequency mixer PGA (programmable) attenuator; Programmable gain amplifier PHS Phase shifter PRE High-frequency preamplifier; Pre-amplifier SYN High-frequency synthesizer UIM Voltage / current measuring circuit 1 High-frequency household appliance; high-frequency kitchen appliance; microwave oven; microwave cooker; Dialog oven 10 Outer casing 11 Treatment chamber; interior; cooking chamber; cavity 12 Interior wall 11 13 Space 2 High-frequency heating module 20 Control unit; Function microcontroller 21 High-frequency signal generator 22 Safety unit; Safety microcontroller 23a-23 First to fourth high-frequency path; First to fourth high-frequency feed

Claims

1. High-frequency domestic appliance (1), preferably a high-frequency kitchen appliance (1), comprising at least one treatment chamber (11) which is designed to accommodate an item to be treated with high-frequency energy, and comprising at least one high-frequency heating module (2) which is designed to generate the high-frequency energy and deliver it into the treatment chamber (11), the high-frequency heating module (2) at least having: • at least one high-frequency signal generator (21) which is designed to generate the high-frequency energy, and • at least one transition (ANT) to the treatment chamber (11) of a first high-frequency path (23a-23d), preferably a transition (ANT) to the treatment chamber (11) of a plurality of high-frequency paths (23a-23d), which transition is designed to deliver high-frequency energy into the treatment chamber (11), the high-frequency heating module (2), preferably at least the first high-frequency path (23a-23d), particularly preferably a plurality of high-frequency paths (23a-23d), most particularly preferably all the high-frequency paths (23a-23d), of the high-frequency heating module (2), further having: • at least one measuring circuit (UIM, FDIV, ADC) which is designed to detect at least one parameter of the high-frequency energy, and • at least one safety unit (22) which is designed to receive the at least one detected parameter from the measuring circuit (UIM, FDIV, ADC) and to evaluate it with regard to compliance with at least one predetermined limit value, the high-frequency heating module (2), preferably the safety unit (22), being designed to operate the high-frequency signal generator (21) on the basis of the evaluation of the parameter, preferably to switch off the high-frequency signal generator (21) when a predetermined limit value of the parameter is exceeded, characterised in that the measuring circuit (UIM, FDIV, ADC) is designed as a voltage / current measuring circuit (UIM) for detecting the voltage and current of the high-frequency energy, preferably of a high-frequency power amplifier (HPA), and the safety unit (22) is designed to receive the detected voltage and the detected current from the voltage / current measuring circuit (UIM), to determine a DC power consumption therefrom, and to evaluate the determined DC power consumption with regard to compliance with a predetermined limit value.

2. High-frequency domestic appliance (1) according to claim 1, characterised in that the predetermined limit value is based on at least one current operating parameter, preferably on the amplitude and / or on the frequency of the high-frequency energy, of the high-frequency heating module (2), preferably of the high-frequency signal generator (21).

3. High-frequency domestic appliance (1) according to claim 1 or claim 2, wherein at least the first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all the high-frequency paths (23a-23d), further has at least one high-frequency coupler (CPL) which is designed to measure the power of a forward-propagating high-frequency wave of the emitted high-frequency energy, and the safety unit (22) is designed to determine an efficiency from the determined DC power consumption and the detected power of the forward-propagating high-frequency wave, and to evaluate the determined efficiency with regard to compliance with a predetermined limit value.

4. High-frequency domestic appliance (1) according to any of the preceding claims, characterised in that at least one first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all the high-frequency paths (23a-23d), further comprises: • at least one first bandpass filter (BPF) which is designed to allow only a predetermined frequency range of the high-frequency energy to pass through.

5. High-frequency domestic appliance (1) according to claim 4, characterised in that at least one high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all the high-frequency paths (23a-23d), further comprises at least one second bandpass filter (BPF) which is redundant to the first bandpass filter (BPF), the second bandpass filter (BPF) preferably being arranged behind, particularly preferably directly behind, a phase shifter (PHS).

6. High-frequency domestic appliance (1) according to any of the preceding claims, characterised in that at least the first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all the high-frequency paths (23a-23d), further comprises: • at least one high-frequency power amplifier (HPA), preferably also at least one high-frequency preamplifier (PRE), which is designed to amplify the high-frequency energy.

7. High-frequency domestic appliance (1) according to any of the preceding claims, characterised in that at least the first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all the high-frequency paths (23a-23d), further comprises: • at least one high-frequency coupler (CPL) which is designed to measure a forward-propagating and / or a backward-propagating high-frequency wave of the emitted high-frequency energy, preferably no amplifier (HPA, PRE) being arranged between the high-frequency coupler (CPL) and the transition (ANT).

8. High-frequency domestic appliance (1) according to any of the preceding claims, characterised in that at least the first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all the high-frequency paths (23a-23d), further comprises: • at least one attenuator (PGA) which is designed to change the amplitude of the high-frequency energy.

9. High-frequency domestic appliance (1) according to any of the preceding claims, characterised in that at least the first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all the high-frequency paths (23a-23d), further comprises: • at least one phase shifter (PHS) which is designed to change the phase of the high-frequency energy.

10. High-frequency domestic appliance (1) according to any of the preceding claims, characterised in that at least the first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all the high-frequency paths (23a-23d), further comprises: • at least one high-frequency isolator (ISO) which is designed to block a backward-propagating high-frequency wave of the emitted high-frequency energy, preferably no amplifier (HPA, PRE) being arranged between the high-frequency isolator (ISO) and the transition (ANT).

11. High-frequency domestic appliance (1) according to any of the preceding claims, characterised in that at least the first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all the high-frequency paths (23a-23d), further comprises: • at least one harmonic filter (HSF) which is designed to block harmonics in a forward-propagating wave of the high-frequency energy, preferably no amplifier (HPA, PRE) being arranged between the harmonic filter (HSF) and the transition (ANT).

12. High-frequency domestic appliance (1) according to any of the preceding claims, characterised in that the high-frequency heating module (2) has at least one control unit (20) which is designed to • receive measurement data of a forward-propagating and / or a backward-propagating high-frequency wave of the emitted high-frequency energy, preferably from a high-frequency coupler (CPL), and • determine at least an amplitude and / or a phase of a forward-propagating and / or a backward-propagating high-frequency wave of the emitted high-frequency energy from the measurement data received.

13. High-frequency domestic appliance (1) according to claim 12, characterised in that the control unit (20) is further designed to operate at least the high-frequency signal generator (21), preferably also at least one attenuator (PGA) and / or a phase shifter (PHS) of at least one high-frequency path (23a-23d), preferably of a plurality of high-frequency paths (23a-23d), particularly preferably of all the high-frequency paths (23a-23d), on the basis of the determined amplitude and / or the determined phase, preferably to change the frequency of the high-frequency energy.

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