WO2008080839A2

WO2008080839A2 - High-frequency sensor and machine tool having a high-frequency sensor

Info

Publication number: WO2008080839A2
Application number: PCT/EP2007/064162
Authority: WO
Inventors: Heiko Braun; Michael Mahler
Original assignee: Robert Bosch Gmbh
Priority date: 2006-12-28
Filing date: 2007-12-19
Publication date: 2008-07-10
Also published as: WO2008080839A3; DE102006062492A1; EP2106320A2

Abstract

The invention relates to a high-frequency sensor, particularly a high-frequency sensor for detecting objects (34) hidden in a medium, comprising at least one antenna (10, 50) for transmitting and/or receiving high-frequency signals (20), particularly signals in a frequency range from 1 to 8 GHz. According to the invention, the at least one antenna (10, 50) is formed on an LTCC substrate (12, 48). The invention further relates to a machine tool, particularly a power tool (18), which is provided for driving a tool by means of boring and/or striking and comprises at least one such high-frequency sensor.

Description

High-frequency sensor and machine tool with a high-frequency sensor

The present invention is based on a high-frequency sensor, in particular a high-frequency position sensor according to the preamble of claim 1.

State of the art

High-frequency sensors, in particular high-frequency sensors for the detection of hidden objects have been known for some time. As high-frequency sensors here sensors or antenna elements such sensors are understood to work in a frequency range of much equal to 1 GHz.

A radar device with a high-frequency sensor is known, for example, from WO 96/19737. With this radar, objects trapped in a wall or in the ground can be detected with high accuracy. So z. B. in holes in a wall, the objects enclosed therein - z. As steel reinforcements, power lines, water pipes and the like - are safe from destruction, should the craftsman precise information about a place, d. H. the path position on the wall surface and the depth in the wall, of the enclosed object are conveyed. A radar device, as also described in WO 96/19737, usually consists of a "front end" - this is a transmitting and receiving unit - and a display device.

The front end disclosed in WO 96/19737 has a shielded space for electrical circuits and two spaces adjoining this space, which are designed as transmitting antenna and receiving antenna. The cavities for the transmitting and receiving antennas are in the form of horns in which radiating elements (eg in the form of wires) are installed. The shielding of the circuit receiving space takes place on the one hand by a mounted on the circuit board for the circuits housing and on the other hand by the Walls of the antenna horns, which are fixed on the opposite side of the circuits of the circuit board. The document WO 96/19737 to be taken execution of the front end of a radar is manufacturing technology relatively expensive because it consists of a variety of items.

From DE 10 104 864 Al a device for transmitting and / or receiving radar beams is known in which on one side of a circuit board at least one antenna and on the other side of the circuit board electrical circuits are arranged and means for electromagnetic shielding of the electrical circuits the at least one antenna are present.

On the antenna-side surface of the printed circuit board of the device of DE 10 104 864 Al is executed in Koplanar- line technology feed network, with which the at least one antenna is contacted, applied, wherein the lying on ground outer conductor of the coplanar line, the antenna-side surface

Covered circuit board so far that this creates the required shielding between the antenna and the electrical circuits.

DE 10 204 568 A1 discloses a radar device for detecting objects enclosed in a wall, which device has a transmitting and receiving device.

Antenna arrangement consisting of at least one cavity with a radiator element arranged therein and a shielded space for electrical

Circuits, wherein the shielded space of the device of DE 10 204

568 Al is formed by a printed circuit board covered by a housing, on whose side facing the interior of the housing, the circuits are applied and on the other side of the antenna assembly is installed. In the apparatus of DE 10 204 568 Al, the housing is formed so that it forms both the shielded space for the circuits and the at least one cavity for the at least one antenna radiating element, wherein the circuit board as a shielding partition between the two spaces in the housing is inserted.

Disclosure of the invention

The invention relates to a high-frequency sensor, in particular a high-frequency sensor for detecting objects hidden in a medium, with at least one antenna for transmitting and / or receiving high-frequency signals, in particular signals in a frequency range from 2 to 8 GHz. In this case, the at least one antenna is formed on a LTCC (Low Temperature Cofired Ceramics) ceramic substrate, wherein LTCCs are ceramic multilayer circuits. By using antennas on LTCC, the size of the antenna can be significantly reduced. LTCC materials have a very high dielectric constant ε _r . This large ε _r and the small layer thicknesses between metal layers, which can be realized, a reduction of the size of the antenna elements in the high frequency range is possible. While currently the antenna technology for high frequency positioning devices in the

UWB (ultra-wide band) range are limited to relatively large antenna dimensions in the range of a few centimeters, the LTCC substrate, the antenna size can be significantly reduced, so that, for example, antenna elements in the frequency range of 2 to 8 GHz with edge lengths less than or equal 1 cm made can be.

Such small antenna sizes provide a number of advantages and new approaches to UWB high frequency localization (Ultra Wide ^ and)

An additional advantage is that such LTCC components can be built up in layer layers, comparable to multilayer boards, and can also be produced like circuit boards.

Since the LTCC components can also contain integrated passive components, such as resistors, capacitors and coils, this opens up further possibilities for integration and space reduction.

By smaller antennas, on the one hand, the size of a corresponding detection device can be reduced, on the other hand is now also the

Use of a whole antenna group in a single device possible.

In addition, the integration of such high-frequency sensors directly in machine tools or adapter elements for machine tools, such as a Staubabsaugevorrichtung, possible. Also in suction aids of vacuum cleaners such antennas and location sensors can be integrated.

The features listed in the dependent claims advantageous developments of the device according to the invention are possible.

Advantageously, the high-frequency components of the transmitting and receiving unit are integrated on or in a semiconductor element (IC) "chip" for short.

Further advantages of the device according to the invention will become apparent from the following description of an embodiment.

drawing

In the drawings, exemplary embodiments of high-frequency sensors according to the invention are shown, which will be explained in more detail in the following description. The figures of the drawing, their description and the

Claims contain numerous features in combinations. A person skilled in the art will also consider these features individually and combine them into further meaningful combinations. In particular, a person skilled in the art will also combine features of different embodiments with each other and thus arrive at further embodiments.

Show it:

1 shows an embodiment of a high-frequency sensor according to the invention with an antenna element on an LTCC substrate in a schematic representation,

2 shows an alternative embodiment of a high-frequency sensor according to the invention with a plurality of antenna elements on a common LTCC substrate in a schematic representation, FIG. 3 shows a typical application situation for a machine tool in a schematic representation,

FIG. 4 shows an alternative application situation for a machine tool in a schematic representation,

FIG. 5 shows an additional component according to the invention for a machine tool with a corresponding high-frequency sensor according to FIG

FIG. 4 in a plan view.

FIG. 1 shows a first exemplary embodiment of a high-frequency sensor according to the invention. The high-frequency sensor according to the exemplary embodiment of FIG. 1 comprises inter alia an antenna element 10 which is mounted on an LTCC

Substrate 12 is formed. (Low Temperature C_ofired C_eramics) LTCCs are multilayer ceramic circuits which, in addition to the integration of, for example, one or more antenna elements, also enable the direct integration of further electronic or electrical components of the high-frequency sensor.

These further electronic components, which can serve, for example, for controlling the antenna elements, are combined schematically in the component 14 in the exemplary embodiment of FIG.

The working frequency range of the antenna or the antennas is typically between 1 and 8 GHz, preferably between 2 and 4 GHz.

The typical length a of an edge of the antenna element 10, which may be formed, for example, as a patch antenna, is in the range of 1 cm and below.

Such a high-frequency sensor can be part of a locating device 16, as is indicated symbolically in FIG. Such a locating device is disclosed, for example, in DE 10 20 5000 A1 and is hereby incorporated in this description, in particular with regard to its structure. FIG. 2 shows an alternative embodiment of a high-frequency sensor according to the invention.

In the device according to FIG. 2, a plurality of antenna elements 10, which may correspond to the antenna element of FIG. 1, are formed on a common LTCC substrate 12.

The typical extension b of an antenna element is 1 cm or significantly lower.

The distance c of the antenna elements 10 to each other is of the order of the size of the antenna elements.

The use of antenna groups in locating devices of the type described in DE 10 204 568 A1, for example, makes it possible to dispense with the hitherto necessary travel path of the devices. In particular, the combination of classical travel and electronic panning characteristics of the antenna array could improve the visibility of trapped objects, especially in corners.

When using antenna groups, there are various approaches. For the sake of simplicity, a linear array as shown in FIG. 2 will be described here. However, the use of an antenna matrix or an antenna star is also possible. Also, a partial occupancy of the matrix, i. an arrangement with different spatial orientation of the individual antennas is possible.

However, the dining options for the relevant antenna groups are always very similar.

The individual antennas are, for example, in a row, as shown in Figure 2, and are also used as individual antennas. Here is then always measured at the place where the respective antenna of the arrangement is located. This corresponds to a device displacement with a fixed measuring distance c according to FIG. 2. Such an application results in a rather coarse grid, which is determined by the antenna distance c. By the simultaneous feeding of the individual antennas 10 with a relative phase difference of the feed signals to each other, a certain directivity of the measuring signal can be achieved and thus the measuring range can be varied. With a fixed adjustment of the phase differences between the antennas, the respective antenna group has always related the same measuring range, for example to the position of the device, for example a locating device, in which a high-frequency sensor is accommodated with a corresponding antenna arrangement. However, if the antennas are varied in their relative phase difference, a change in the measuring range is associated with it. This means that the device must not be moved over the desired measuring range.

This then gives u.a. subsequent operating options for a corresponding locating device.

The measuring device is aligned with an object to be measured, for example a housing wall, and the variable antenna control means that a specific measuring range below the device can now be examined.

Alternatively, the device, as previously customary and described in DE 10 20 5000 Al - fixed with fixed measuring direction of the antenna array - be moved over, for example, a wall. If the meter comes to a place where it can not be moved on, such as a room corner or the like. Can now be used by changing the antenna control a pivoting characteristic of the antenna array to measure the inaccessible or difficult to reach area.

Furthermore, an operating mode is possible in which the locating device is moved over the wall and takes measurements in a relatively coarse spatial grid. In addition, the measuring range can be changed by changing the phase angle of the

Drive signal of the individual antennas are finely varied at each grid point. By this method, the spatial resolution of the meter can be improved.

Furthermore, additional information about trapped objects in the material to be examined can be obtained by adjusting the angle of incidence of the electromagnetic wave emitted by the antennas on the wall by varying the relative phase angle of the antenna elements. As a result, objects are "visible" not only directly from the front but also obliquely from the side.

FIG. 2 shows a machine tool 18 in the form of a drilling machine with a corresponding individual antenna element 50 which is mounted on an LTCC substrate

48 is arranged. The antenna element is operated by a corresponding control electronics 52. In alternative embodiments, an antenna array according to FIG. 2 or an antenna matrix in the machine 168 may also be used.

The electromagnetic high-frequency signal 20, which is radiated by the antenna, can be coupled out, for example, via a so-called polyrod and / or directed via a dielectric lens 22: for decoupling the energy from the antenna 50, which can be designed in particular as a patch antenna, can - depending on the operating frequency of the high-frequency sensor, a dielectric in the form of a plastic part, which is referred to as polyrod, find use. The polyrod is placed over the antenna element. An additional shaping of the directional geometry of the radiator element can be achieved via the housing geometry, or a dielectric lens.

In the exemplary embodiment of FIG. 3, a hole is to be drilled in a wall 28 by means of a drill. In the wall of thickness D is a pipe 34, for example made of a plastic, which should not be drilled as possible.

With the aid of the high-frequency sensor according to the invention, which is integrated in the machine tool, the plastic tube which is hidden in the wall 28 can be detected and, for example, a corresponding warning signal or the direct display of the hidden object in an output unit 54 of the machine tool 18 are reproduced. Alternatively, it is possible to throttle or switch off the machine, if any - especially specifiable

- Minimum distance to the enclosed object is fallen below.

Since, in addition to the enclosed object 34, the wall front side 30 as well as the wall rear side 36 can be detected via reflections of the high-frequency signal 20, a so-called machine tool can also be used with a machine tool according to the invention

Wall breakthrough be prevented. The high-frequency sensor can, for example, determine the wall thickness D and turn off the machine 18, if a wall breakthrough is imminent. A wall breakthrough is characterized in that the drilling depth is equal to or greater than the respective wall thickness.

In the embodiment of Figures 4 and 5, the high-frequency sensor is not integrated in the machine tool itself, but in an additional component 60, which in the embodiment of Figures 4 and 5 is a suction device for the Bohrstaub. Such a suction device can be placed directly on the wall 28 at the drilling point or be connected to the machine tool 18, as symbolized by the connecting element 62 in FIG.

Through an opening 64 in the suction device 60, the drill 66 can be guided, as shown in the plan view of a suction device 60 according to Figure 5. Around the aperture 64, antenna elements 10 are disposed on a common LTCC substrate. Alternatively, each antenna element may be formed on its own on an LTCC substrate. Also, an embodiment with only one antenna element is possible, so that the high-frequency sensor can only decide whether an object is present or not.

The antennas 10 of the antenna group can optionally be operated individually or interconnected as an antenna group. The individual antennas can thus be used as a single element depending on the requirement, for example for determining "enclosed object present, yes or no" or by using in an antenna group, for example in a star or cross arrangement also identify the direction of the enclosed objects.

Other necessary electronics could either in the suction itself, optionally with appropriate display elements or even in the

Be housed drilling machine. Also, the integration of electronic components directly on or in the LTCC substrate is advantageously possible.

The invention is not limited to the embodiments shown in the figures. In particular, the invention is not limited to the type and shape of the machine tool or, the additional component for the machine tool.

Claims

claims

1. high-frequency sensor, in particular a high-frequency sensor for detecting objects hidden in a medium (34), with at least one antenna (10,50) for transmitting and / or receiving high-frequency signals (20), in particular signals in a frequency range of 1 to 8 GHz , characterized in that the at least one antenna (10, 50) is formed on an LTCC substrate (12, 48).

2. High-frequency sensor according to claim 1, characterized in that the at least one antenna (10,50) is a patch antenna.

3. High-frequency sensor according to claim 1, characterized in that the at least one patch antenna has an edge length a of less than or equal to 1 cm.

4. High-frequency sensor according to one of the preceding claims, characterized in that the sensor comprises a plurality of antenna (10,50).

5. High-frequency sensor according to claim 4, characterized in that the plurality of antenna (10,50) on a common LTCC substrate (12,48) is arranged.

6. High-frequency sensor according to one of the preceding claims, characterized in that in or on the LTCC substrate (12,48) electronic components (14), in particular resistors, capacitors or coils are integrated.

7. Machine tool, in particular a power tool (18), which is provided for a drilling and / or beating driving a tool, with at least one high-frequency sensor according to one of the preceding claims.

8. Additional component for use in conjunction with a machine tool, in particular in conjunction with a power tool (18), which is provided for a drilling and / or beating driving a tool (66), characterized in that the additional element (60) at least one high-frequency sensor according to at least one of claims 1 to 6.

9. additional component according to claim 8, characterized in that the additional component is part of a suction device (60).