US-12627065-B2 - Apparatus, in particular measuring device having an antenna, for acquiring a consumption quantity

US12627065B2US 12627065 B2US12627065 B2US 12627065B2US-12627065-B2

Abstract

An apparatus, in particular a measuring device, for acquiring a consumption quantity, includes a housing, a circuit board disposed inside the housing, a communication device, and an antenna disposed on the circuit board. The communication device is adapted to transmit data at a given carrier frequency between the apparatus and an external device via the antenna. A dielectric with changeable permittivity with respect to the carrier frequency is disposed inside the housing. The circuit board and/or a metallic or metal-containing shielding device is disposed between the dielectric and the antenna and/or a minimum distance of the antenna from the dielectric is at least 30% or at least 50% of a maximum diameter of the interior of the housing.

Inventors

Simon Schröter
Michael Sigl
Jean-Bruno Togni

Assignees

DIEHL METERING SYSTEMS GMBH
Diehl Metering S.A.S

Dates

Publication Date: 20260512
Application Date: 20240411
Priority Date: 20230512

Claims (18)

1 . An apparatus or measuring device for acquiring a consumption quantity, the apparatus comprising: a housing having an interior with a maximum diameter; a circuit board disposed inside said housing; an antenna disposed at or on said circuit board; a communication device adapted to transmit data at a given carrier frequency between the apparatus and an external device via said antenna; a dielectric disposed inside said housing, said dielectric having a permittivity influencing a range or efficiency of said antenna relative to the given carrier frequency; and at least one of: said circuit board or a metallic or metal-containing shielding device being disposed between said dielectric and said antenna, or a minimum distance being provided from said antenna to said dielectric, said minimum distance being at least 30% of said maximum diameter.
2 . The apparatus according to claim 1 , wherein said minimum distance is at least 50% of said maximum diameter.
3 . The apparatus according to claim 1 , wherein said dielectric is a drying agent.
4 . The apparatus according to claim 1 , wherein said permittivity of said dielectric relative to the carrier frequency changes by at least 50% over a given operating time period of the apparatus.
5 . The apparatus according to claim 4 , wherein said permittivity of said dielectric relative to the carrier frequency changes at least one of: as a result of ageing of said dielectric, or until said dielectric becomes saturated with water.
6 . The apparatus according to claim 5 , wherein said dielectric becomes saturated with water as a result of at least one of adsorption or chemical binding of water.
7 . The apparatus according to claim 1 , wherein said dielectric is disposed at a distance of at least 2 mm from edges of said circuit board.
8 . The apparatus according to claim 1 , wherein said dielectric is disposed at a distance of at least 10 mm from edges of said circuit board.
9 . The apparatus according to claim 1 , wherein: said circuit board has mutually opposite first and second edges; said antenna is disposed on said circuit board between said first edge and said second edge; said antenna is disposed closer to said first edge than to said second edge; and said dielectric is disposed closer to said second edge than to said first edge.
10 . The apparatus according to claim 1 , which further comprises a metallic or metal-containing component disposed between said dielectric and at least one edge of said circuit board.
11 . The apparatus according to claim 10 , wherein at least one of said shielding device or said metallic or metal-containing component is an electrical component of the apparatus.
12 . The apparatus according to claim 10 , wherein at least one of said shielding device or said metallic or metal-containing component is an energy store for providing energy for at least one of said communication device or at least one component for acquiring measurement data.
13 . The apparatus according to claim 1 , wherein at least one of said shielding device or said metallic or metal-containing component is or includes at least one of a wire mesh, or a metal sheet, or metallic threads, or particles in a matrix material, or a metal-coated carrier material.
14 . The apparatus according to claim 13 , wherein said metal sheet is perforated.
15 . The apparatus according to claim 1 , which further comprises: a cuboidal holding volume receiving said dielectric; and at least one of said shielding device, or said circuit board, or said metallic or metal-containing component delimiting said cuboidal holding volume on at least two or at least three or at least four or at least five or six side faces of said cuboidal holding volume.
16 . The apparatus according to claim 15 , which further comprises: a cuboidal holding volume receiving said dielectric; at least one of said shielding device, or said circuit board, or said metallic or metal-containing component delimiting said cuboidal holding volume on at least two or at least three or at least four or at least five or six side faces of said cuboidal holding volume; a closing device having a closed position closing said recess or a further side face of said holding volume; said closing device being movable or pivotable relative to said recess or said holding volume from said closed position into an open position for freeing an opening of said recess or of said holding volume; and said dielectric configured to be at least one of introduced into or removed from said recess or said holding volume through said opening.
17 . The apparatus according to claim 1 , wherein: said housing has an inner surface; said housing includes a recess having a base formed by said inner surface and a rim formed by said inner surface; said base is spaced further apart from said circuit board than said a rim; and said dielectric is held in said recess.
18 . The apparatus according to claim 1 , which further comprises: a further circuit board; said dielectric being disposed between said circuit board and said further circuit board and said dielectric having sides; said circuit board and said further circuit board each having a respective conducting surface; and a connecting device being disposed on at least one of said sides of said dielectric and connected to said conducting surfaces of said circuit board and said further circuit board.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the priority, under 35 U.S.C. § 119, of German Patent Application DE 10 2023 112 588.5, filed May 12, 2023; the prior application is herewith incorporated by reference in its entirety. FIELD AND BACKGROUND OF THE INVENTION The invention relates to an apparatus, in particular a measuring device for acquiring a consumption quantity, having a housing, a circuit board disposed inside the housing, a communication device, and an antenna disposed at or on the circuit board, wherein the communication device is adapted to transmit data at a given carrier frequency between the apparatus and an external device via the antenna, and a dielectric with changeable permittivity with respect to the carrier frequency is disposed inside the housing. The electronics of measuring devices for acquiring a consumption quantity, for example of water, electricity and heat meters, must frequently be protected from environmental influences and in particular from moisture. One possible method for achieving that is to encapsulate the electronics or to close the housing by using potting compound. However, that makes maintenance of the measuring device more difficult. European Patent EP 3 550 272 B1, corresponding to U.S. Pat. Nos. 11,619,529 and 11,644,352, for example, discloses the use of a drying agent for moisture protection in corresponding measuring devices, the drying agent being able to absorb moisture that penetrates the housing. As a result, it can be possible to dispense with encapsulation of the electronics or of the housing. However, it has been recognized within the scope of tests that, although the use of drying agent in a measuring device is unproblematic for communication with the measuring device in the case of the use of relatively high carrier frequencies of, for example, 868 MHz in the UHF band, in the case of the use of lower carrier frequencies, for example at 169 MHz in the VHF band, the use of a drying agent in the housing can have the result that the communication range decreases over the operating time and/or that, after a certain operating time, a higher energy consumption of the communication device results. SUMMARY OF THE INVENTION It is accordingly an object of the invention to provide an apparatus, in particular a measuring device having an antenna, for acquiring a consumption quantity, that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type, which occur in particular when lower-frequency carrier frequencies are used for communication, when using a drying agent in an apparatus provided with a communication device. With the foregoing and other objects in view there is provided, in accordance with the invention, an apparatus of the type mentioned at the beginning, wherein on the one hand the circuit board and/or a metallic and/or metal-containing shielding device is disposed between the dielectric and the antenna, and/or on the other hand the minimum distance of the antenna from the dielectric is at least 30% or at least 50% of the maximum diameter of the interior of the housing. It has been recognized within the scope of the invention that the presence of a dielectric in the vicinity of the antenna used for communication can influence the properties of the antenna, for example the impedance and resonant frequency thereof. While the presence of a dielectric with constant or at least approximately constant permittivity in respect of the carrier frequency can be taken into consideration in the configuration of the communication device or of the antenna, so that an optimum transmission amplitude or efficiency can be achieved, this is not possible in the case where the permittivity of the dielectric changes significantly over time. The permittivity is also referred to as the dielectric constant. In the case of drying agents, the permittivity can change considerably as a result of the absorption of water. In the dry state, conventional drying agents have a relative dielectric constant of between 3 and 10. Water has a relative dielectric constant of approximately 80. Saturation of conventional drying agents typically results in a water content of about 20%. Thus, the water absorption leads to an increase in the dielectric constant or permittivity by about 150% of the permittivity in the dry state. This generally leads to significant detuning of the resonant frequency of the antenna and thus, depending on the bandwidth of the antenna, frequently to a significantly lower range or efficiency. If the apparatus is, for example, a smart meter consumption meter, the installation space available for the antenna is generally rather small. As a result, the maximum usable overall height of the antenna can be limited, for example, to 5 cm or even to 3 cm. Therefore, the usable antennae in the UHF and VHF band are electrically small antennae. At high carrier frequencies of, for example, 868 MHz, or in the UHF band,