MICROWAVE GENERATOR FOR A MICROWAVE DEVICE AND MICROWAVE DEVICE

Abstract

A microwave generator for a microwave device includes a single component carrier for control components and power components, which includes a continuous carrier material. Two power regions and one control region are provided on the component carrier. In the control region, electrically functional components are arranged on both flat sides of the component carrier, while in the power regions, electrically functional components with at least one power switch are arranged only on an upper flat side, heat sinks being arranged on the lower flat side. An RF substrate is provided in regions on the upper flat side of the power region.

Claims

1. A microwave generator for a microwave device, comprising: a single component carrier for control components and power components of said microwave generator, said component carrier comprising two flat sides; said component carrier further comprises: a continuous carrier material; and at least one power region and at least one control region are provided on said component carrier, wherein: in said control region, electrically functional components are arranged on both said flat sides of said component carrier; in said power region, electrically functional components with at least one power switch are arranged only on a first of said flat sides; and in said power region, heat sinks, cooling means are arranged on a second of said flat sides.

2. The microwave generator according to claim 1, wherein: said component carrier is the only component carrier for electrically functional components for microwave generation of said entire microwave device.

3. The microwave generator according to claim 1, wherein: an RF substrate is arranged on said component carrier.

4. The microwave generator according to claim 3, wherein: said RF substrate is arranged on an upper flat side in said power region, wherein on said upper flat side said power switches are also mounted.

5. The microwave generator according to claim 4, wherein: said power switches are mounted on said RF substrate.

6. The microwave generator according to claim 3, wherein: said RF substrate is fitted sunk in a recess into said upper flat side of said component carrier.

7. The microwave generator according to claim 3, wherein: said RF substrate is fitted flush with a surface of said component carrier.

8. The microwave generator according to claim 1, wherein: in a region directly below one of said power switches, a recess extending fully through said component carrier is provided, wherein a good heat conductor is fitted into said recess, said power switch being arranged on an upper side of said heat conductor, wherein a heat sink or other cooling means are thermally conductively connected to a lower side of the heat conductor.

9. The microwave generator according to claim 8, wherein said good heat conductor comprises copper.

10. The microwave generator according to claim 1, wherein: a first said power region is arranged on one side of said control region, and beside said first power region a second power region is arranged on another side of said control region.

11. The microwave generator according to claim 1, wherein: in said control region, only SMD components are arranged on one said flat side of said component carrier, and only THT components are arranged on said other flat side of said component carrier.

12. The microwave generator according to claim 11, wherein: said SMD components are arranged on an upper one of said flat sides of said component carrier, wherein also power switches of said power region are arranged on said upper side of said component carrier.

13. The microwave generator according to claim 1, wherein: a power measurement, a communication connection and at least one connection for at least one door contact are arranged on said single component carrier.

14. The microwave generator according to claim 1, wherein: a circulator is provided on said component carrier in order to detect fed-back microwaves, said circulator being configured in order, at an input of a drive of said power components, to modify a driving of said power components by feedback in such a way that said power components are not damaged by said fed-back microwaves.

15. The microwave generator according to claim 1, wherein: at least one signal of at least one coupler acts back on at least one oscillator and/or at least one gain of said power switches and/or at least one voltage supply of said power switches, in order to reduce or switch off a microwave incidence into said compartment in an event of an excessively high reflected microwave.

16. A microwave device comprising a microwave generator according to claim 1.

17. The microwave device according to claim 16, said microwave device being a microwave oven.

18. The microwave device according to claim 16, wherein: all interfaces of said microwave generator, or of said component carrier of said microwave generator, are provided in one direction.

19. The microwave device according to claim 18, wherein: all said interfaces are provided in a direction towards a front side of said microwave device.

20. The microwave device according to claim 19, wherein: a connection to a door contact is fed to said microwave generator from said front side of said microwave device.

21. The microwave device according to claim 20, wherein: at least one fan is arranged on a rear side of said component carrier.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0028] Exemplary embodiments of the invention are schematically represented in the drawings and will be explained in more detail below. In the drawings:

[0029] FIG. 1 shows a schematic plan view of a microwave generator according to the invention for a microwave device according to the invention;

[0030] FIG. 2 shows a section through the microwave generator, or its component carrier, of FIG. 1; and

[0031] FIG. 3 shows a highly schematized side view of a microwave device according to the invention in the form of a microwave oven.

DETAILED DESCRIPTION

[0032] FIG. 1 schematically represents a plan view of a microwave generator 11 according to the invention. This microwave generator 11 is, as described above, configured for so to speak two channels, as is known from US 2016/183332 A1. The microwave generator 11 comprises a single continuous component carrier 13, advantageously consisting of a per se conventional circuit board material, such as FR4. This is then processed further according to the invention, as will be explained below.

[0033] The component carrier 31 has an upper flat side 14a and a lower flat side 14b, as can be seen above all in the sectional representation of FIG. 2 along the dot-and-dash line A-A. The component carrier 13 is subdivided into a central control region 16 and, on the left and right thereof, two power regions 17a and 17b. Here, the power region 17a is provided above the control region 16 and the power region 17b is provided underneath.

[0034] A switched-mode power supply 19 is provided in the control region 16, advantageously on the lower side, or on the lower flat side 14b, of the component carrier 13, as can be seen from FIG. 2. In the control region, measurement circuits 21a and 21b are provided on the right of the switched-mode power supply 16, one for each channel. Arranged between them, there is a microcontroller 22 for the entire microwave generator 11, and optionally even for the entire microwave device comprising this microwave generator. Connections 24 for inputs are provided, an upper input 25a being used for the communication, in particular coming from control elements or the like on the microwave device. A central input 25b is provided for the door contacts mentioned in the introduction, and a lower input 25c is a power connection. The latter is connected through as directly as possible to the switched-mode power supply 19 by means of the connections 24.

[0035] On the left thereof, and as directly as possible to the switched-mode power supply 19, oscillators 26a and 26b are provided, again one for each channel. Although these bridge, so to speak, or the central or middle control region 16, they do in fact at least partially belong to the radiofrequency components and therefore to the power regions 17a and 17b. The oscillators 26a and 26b are each connected to an amplifier 29a and 29b. These amplifiers 29a and 29b respectively comprise a power switch 30a and 30b, which can be additionally driven with signals by the microcontroller 22 and supplied with power by the switched-mode power supply 19.

[0036] The amplifiers 29a and 29b, or their power switches 30a and 30b, are connected to isolators 43a and 43b, as are known from the prior art, although each of these may be omitted if there are corresponding switch-off devices. The isolators are connected to couplers 45a and 45b, to the respective RF outputs of which antennas 46a and 46b are connected. This is again known from the prior art. Instead of the antennas 46, which are advantageously configured as waveguides, a coaxial cable could also be connected. This, however, would be required overall only in the event of sizeable distances, but would at the same time be elaborate and functionally disadvantageous because of the longer paths and larger number of connections.

[0037] To the left on the component carrier 13, or on a rearward edge, three fans 47 are provided, advantageously fastened on the component carrier 13 or connected thereto to form a module, for example by conventional fastening brackets or the like. These cool the microwave generator 11, in particular its amplifiers 29 or power switches 30 and the switched-mode power supply 19. A readily preassemblable and readily installable module is thus obtained.

[0038] As can be seen from the regions of the upper flat side 14a of the component carrier 13 which are defined by dots in FIG. 1, the RF substrate mentioned in the introduction may be provided here. For more detailed explanation, reference is made to FIG. 2, which is described below.

[0039] FIG. 2 shows the central control region 16, which has the power region 17a next to it on the left and the power region 17b on the right. In the control region 16, the control components 20a in the form of SMD components are provided on an upper flat side 14a of the component carrier 13. Advantageously, only SMD components are provided here, so that an installation height can be kept relatively small. On a lower flat side 14b of the component carrier 13, further control components 20b are provided, which are configured as so-called THT components with schematically represented connection pins, which extend through through-holes (not represented or explained in detail) in the component carrier 13 and are soldered onto one of the flat sides 14a or 14b. To represent the switched-mode power supply 19, a relatively large THT component is represented here. All the THT components of the control region 16 are arranged on the lower flat side 14b, so that their naturally relatively large installation height is only provided there.

[0040] The aforementioned further constituents of the control region 16, such as measurement circuits 21a and 21b as well as the microcontroller 22, including the connections 24, may also be arranged on the upper flat side 14a of the component carrier 13. This is not represented in detail here. It depends essentially on their design, i.e. whether they are SMD components or THT components. Optionally, the connections 24 may be provided on the lower flat side 14b and connected by means of known through-contacts to the upper flat side 14a. This arrangement would have the advantage that direct through-contacting of the power input 25c to the switched-mode power supply 19 on the lower flat side 14b is then possible. In the installed state, the connections 24 advantageously point toward a front, or front side, of the microwave device so that they, or the entire microwave generator 11, as explained in the introduction, can be contacted more easily.

[0041] In the power regions 17a and 17b, the two channels of the microwave generator 11 are constructed substantially symmetrically. Here, as a particular feature, the arrangement of RF material or RF substrate 33 in recesses 32 in the upper flat side of the component carrier 13 can be seen. It could, however, likewise be applied onto the upper flat side without a recess, i.e. surface-wide. The thickness of the RF substrate 33, or the depth of the recesses 32, may in this case constitute about 40% of the total thickness of the component carrier 13, although it may also be more or less. The introduction of the RF substrate 33 into the recesses 32 may be carried out in a manner known per se, for example by placement, lamination, casting or adhesive bonding of corresponding flat material into previously produced recesses in the component carrier 13. The provision of the RF substrate 33 having very good dielectric properties in this region is used to reduce the emissions where the radiofrequency components are fitted, particularly in the power region.

[0042] The high-quality RF substrate 33 is not required in the region of the microcontroller 22 and of the switched-mode power supply 19, or in the entire control region 16. The RF substrate 33 may, for example, be obtained from the company Rogers. By its incorporation, a kind of hybrid component carrier or hybrid circuit board is provided.

[0043] The power switches 30a and 30b are placed on the RF substrate 33, or lie thereover. Since the heat conduction properties of the RF substrate 33 are not particularly good, a hole 35 through the component carrier 13 in which heat conductors 36a and 36b, so-called thermocoins, are provided, is respectively arranged below the power switches 30. These advantageously consist of copper and conduct the heat from the power switches 30 downward to respective heat sinks 38. These heat sinks 38 are firmly screwed below on the component carrier 13 in a known manner by means of screws 39. RF screening 41 is respectively provided above the power switches. This ensures less emission of spurious signals. Such RF screening 41 may be configured as a kind of cover made of sheet metal, die-casting or similar material. A sheet-metal cover in this case appears particularly advantageous since it can have mounting lugs that can be fitted through holes in the component carrier 13 and subsequently clamp or be interlocked for fastening.

[0044] The representations reveal the compact size advantageously achieved according to the invention, as well as the short connection paths. For example, the distance between the switched-mode power supply 19 and the oscillators 26 and the amplifiers 17, together with the power switches 30, is very short. Even high currents can thus be conducted well, a single switched-mode power supply being sufficient for this.

[0045] The measurement circuits 21 are used to measure the power via the couplers 45. A control loop can therefore be set up via the microcontroller 22 back to the oscillators 26 and the amplifiers 17, in order to keep the power constant and, for example, compensate for temperature drift. In addition, rapid switching off of the amplifiers on the hardware side may be implemented when exceeding the return power to the coupler. By means of this, the circulators can be omitted and the power switches 30 are nevertheless protected.

[0046] In a general configuration of the invention, provision may be made for the switched-mode power supply to be configured in such a way that its output voltage is variable. Power adaptation of the microwave generator 11 can thus be carried out, for example in the event of a poor power input into food to be cooked in the case of a microwave oven according to the invention as the microwave device. Furthermore, rapid reaction or influencing from one channel onto the other is possible by virtue of the compact design of the microwave generator 11. Furthermore, integration of the switched-mode power supply 19 into the microwave generator 11, or on its single component carrier 13, reduces the installation size and saves on material costs and assembly costs, for example by virtue of local capacitors for temporary storage of charge. In addition, perturbing effects can be avoided.

[0047] Tuning of the RF circuit in a power region may be carried out directly on the component carrier 13. To this end, integrated tuning means may be provided, as actually known per se to the person skilled in the art.

[0048] FIG. 3 represents a microwave device according to the invention as a microwave oven 50. The microwave oven 50 comprises a housing 51 having a door 52, which leads into a compartment 54 as the cavity. Above this, the microwave generator 11 according to the invention is arranged in the housing 51. The fans 47 feed air onto a rear side of the housing 51, or are supplied there with fresh air. The microwave generator 11 extends at least partially over the compartment 54. The above-described antennas 46 are directed downwards, or onto the compartment 54.

[0049] Door contacts known per se (not represented in detail here) are provided on the door 52, for example where the door 52 engages in a kind of lock or latch on the housing 51. These door contacts are fed at the input 25b to the connections 24, in accordance with FIG. 1.