Ultra-compact broadband LTE IoT metal stamping antenna for water meter

Abstract

The invention relates to an ultra-compact broadband LTE IoT metal stamped antenna for a water meter. An antenna device may include an antenna and a plastic substrate that may support two or more different metal structures for the antenna, where the antenna includes a pattern of quarter-wavelength antenna structures that is curved to fit a limited area and proximate to a metal component, and slotted to achieve transmitter radiation power at a broadband frequency. The antenna arrangement may also include a radiating element mounted over the ground plane and having a plurality of branches over the ground plane to achieve broadband frequencies. The antenna arrangement may also include a parasitic element that improves a resonant frequency in a high frequency band.

Description

[0001] Cross Reference to Related Patent Applications

[0002] This patent application claims priority to Indian Provisional Patent Application No. 202411034421, filed April 30, 2024, which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] Embodiments relate generally to devices for transmitting or receiving electromagnetic waves, including antennas used in communications, wireless networks, and other applications. Embodiments also relate to antennas used with battery-powered devices such as water meters. Embodiments also relate to wideband antennas. Embodiments also relate to metering devices, such as water meters equipped with wireless communication devices and systems that support multiple frequency bands. BACKGROUND

[0004] Long Term Evolution Category Narrow Band Internet of Things (LTE CAT NB1) has become the preferred Low Power Wide Area Network (LPWAN) solution for battery-powered devices, especially in applications such as water metering. This preference stems from its wide coverage, secure and reliable communication, and extremely low battery consumption, among other characteristics.

[0005] Water meters equipped with Narrow Band Internet of Things (NBIoT) as the communication technology need to support multiple frequency bands, which can vary depending on the network provider (operator) and geographical location. To ensure seamless NBIoT wireless connectivity at any available site, global NBIoT bands must be supported.

[0006] It is critical for the efficiency and reliability of maintaining wireless connectivity that the transmitter radiated power (TRP) needs to be at least 18 dBm in all frequency bands, including B1 (2100), B3 (1800), B5 (850), B8 (900), B20 (800), and B28 (700).

[0007] However, achieving the required antenna radiated performance is a significant challenge, limited by water meter installation. The maximum overall height of the water meter, as well as the close proximity to other active or metallic components such as LCD, NFC module, and battery, all contribute to the limitation. Notably, lower frequencies require a larger antenna height, which often exceeds the size allowed for water meter installation, especially for the B28 (700 MHz) band.

[0008] Furthermore, the electronics of the water meter are often encapsulated or potted to protect them from harsh environmental conditions, which further compounds the difficulty of achieving the required radiated performance.

[0009] Large scale manufacturing can cause variability in antenna performance due to differences in antenna metal structure during assembly. Additionally, potting material can degrade antenna radio frequency (RF) connector performance, which exacerbates the challenge of maintaining a stable and reliable connection. SUMMARY

[0010] The following summary is provided to facilitate an understanding of some features of the embodiments disclosed herein and is not intended to be a complete description. A full appreciation of various aspects of the embodiments disclosed herein can be gained by taking the description, claims, drawings, and abstract as a whole.

[0011] Accordingly, one aspect of an embodiment is to provide an improved wideband antenna usable with battery powered devices such as water meters.

[0012] Another aspect of an embodiment is to provide an improved wideband antenna.

[0013] Yet another aspect of an embodiment is to provide a planar inverted-F antenna (PIFA) quarter wavelength LTE IoT antenna.

[0014] The above aspects and other objects can now be achieved in the manner described herein. An antenna apparatus can include an antenna and a plastic substrate supporting at least two different metal structures for the antenna, wherein the antenna includes a quarter wavelength antenna structure pattern that is bent to fit a limited area and close to a metal component and is slotted to achieve transmitter radiated power at a wideband frequency, a radiating element mounted above a ground layer and having multiple branches above the ground layer to achieve a wideband frequency, and a parasitic element that improves resonant frequencies in a high frequency band.

[0015] One embodiment of the antenna apparatus can include a feed leg and a shorting pin.

[0016] In one embodiment of the antenna apparatus, the feed leg can support a first branch of the radiating element above the ground layer and can electrically couple the first branch to an RF feed port and an impedance matching network.

[0017] In one embodiment of the antenna apparatus, the shorting pin can support a second branch of the radiating element above the ground layer and can electrically couple the second branch to a printed circuit board.

[0018] In one embodiment of the antenna apparatus, the plastic substrate can control antenna radiation performance variation of large scale manufacturing.

[0019] In one embodiment of the antenna apparatus, the antenna can be directly connected to an RF feed port of an element RF connector to address performance issues caused by potting material.

[0020] In one embodiment of the antenna device, the antenna can be partially potted to protect the electronics from harsh environmental conditions.

[0021] In one embodiment, an antenna device can include an antenna and a plastic substrate supporting at least two different metal structures for the antenna, wherein the antenna includes a quarter wavelength antenna structure pattern that is curved to fit a limited area and close to metal components and slotted to achieve transmitter radiated power at a wideband frequency; and a radiating element mounted above a ground layer and having multiple branches above the ground layer to achieve the wideband frequency.

[0022] In one embodiment, a method of operating an antenna device can involve achieving transmitter radiated power at a wideband frequency with an antenna and a plastic substrate supporting at least two different metal structures for the antenna, wherein the antenna includes a quarter wavelength antenna structure pattern that is curved to fit a limited area and close to metal components and slotted to achieve the transmitter radiated power at the wideband frequency; with a radiating element mounted above a ground layer and having multiple branches above the ground layer to achieve the wideband frequency; and with a parasitic element associated with the antenna device to improve resonant frequencies in a high frequency band. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings illustrate the present application and, together with the detailed description, serve to explain the principles of the present application, wherein like reference characters designate like or functionally similar elements throughout the several views, and in which:

[0024] Figure 1 illustrates a front perspective view of an antenna that can radiate in NBIOT bands B3, B8, B20 according to one embodiment;

[0025] Figure 2 illustrates a front perspective view of another antenna that can radiate in NBIOT bands B3, B28 according to one embodiment;

[0026] Figure 3 illustrates a view of an antenna positioned above a PCB ground layer as Figure 1 depicted according to one embodiment;

[0027] Figure 4 illustrates a view of an antenna positioned above a PCB ground layer as Figure 2 depicted according to one embodiment;

[0028] Figure 5 illustrates a view of an antenna positioned above a PCB ground layer asFigure 1 a perspective view of an antenna assembly including an antenna device disposed on a printed circuit board in association with a communication module.

[0029] Figure 6 an antenna assembly according to one embodiment is illustrated as Figure 2 a perspective view of an antenna assembly including an antenna device disposed on a printed circuit board in association with a communication module.

[0030] In the drawings described below, like or similar elements are referred to using the same reference designators. DETAILED DESCRIPTION

[0031] The specific values and configurations discussed in these non-limiting examples can be varied, and are cited by way of example only, and are not intended to limit the scope of the application.

[0032] The subject matter will now be described more fully with reference to the accompanying drawings, which form a part of this specification, and in which illustrative embodiments are shown by way of example, and in which:

[0033] Throughout this specification and the claims, unless the context dictates otherwise, the term "comprise" and variations of the term, such as "comprising" and "comprises", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. Similarly, unless the context dictates otherwise, the term "comprise" and variations of the term, such as "comprising" and "comprises", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. Also, as used in this specification and the claims, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. Similarly, the terms "another" and "an additional" are used interchangeably and mean "one or more than one." Also, the term "plurality" means "two or more than two."

[0034] Generally, the terminology can be understood at least in part from usage of the terms in the context in which they are used. For example, the terms such as "and", "or", or "and / or" as used herein can include a variety of meanings that can depend at least in part upon the context in which such terms are used. Typically, "or" if used to associate a list, such as A, B, or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B or C, here used in the exclusive sense. In addition, the term "one or more" or "at least one" as used herein, can be used to describe any feature, structure, or characteristic in the singular or can be used to describe combinations of features, structures or characteristics. Similarly, terms such as "one," "a," or "the" again are intended to be construed to deliver either a singular or plural usage, at least in part, depending on the context in which such terms are used. Furthermore, the term "based on" can be understood as not necessarily intended to convey an exclusive set of factors, but rather can allow for existence of additional factors not necessarily expressly described, again at least in part, depending on the context in which such term is used. Also, as used herein, the term "at least one of' can mean "one or more of." For example, "at least one of a widget" can mean "one or more widgets."

[0035] The disclosed embodiments relate to two different types of LTE IoT antennas that have the same physical size, can be specifically tailored for water meters, and are capable of supporting frequency bands ranging from 700 MHz to 2100 MHz. These antennas can utilize a metal stamped radiating component attached to a plastic substrate. The plastic substrate serves a dual purpose of providing structural support to the antenna and helping to manage antenna radiation performance variations during mass production.

[0036] Both antennas can employ a standardized plastic substrate, form factor, and connector pin, facilitating compatibility with the same housing and printed circuit board assembly (PCBA). The antenna design employs a two-point electrical coupling system to connect the RF feed port and ground. To prevent water ingress to the internal electronics, a portion of the feed leg extends below the potting material, while the rest remains above the potting material along with the radiating element to meet the required radiation performance standards.

[0037] The mechanical structure of the antennas can be designed with a unique polarization configuration to ensure omnidirectional radiation performance across a wide spectrum of frequencies, from low to high bands. The antennas are attached to the electronic PCB with a simple process of just two-point soldering and press-fitting, enabling a streamlined assembly for mass production.

[0038] Furthermore, the plastic structure of the antenna is carefully designed to support the radiating elements, minimizing variations and ensuring a robust placement on the PCB through multiple ribs. In addition, the design of the antenna embodiments discussed herein can allow for efficient flow of potting material during encapsulation, thereby enhancing protection of the internal electronics.

[0039] Figure 1 A front perspective view of an antenna device 100 that can be implemented according to one embodiment is illustrated. As Figure 1 The depicted antenna device 100 can be implemented as a Narrow Band Internet of Things (NBIOT or NBIoT) device or together with it. The antenna device 100 can comprise a parasitic element 102 and a high frequency radiator 104. Furthermore, the antenna device 100 can be designed to comprise a low frequency radiator 110. The antenna device 100 can further comprise an RF feed line or feed leg 106 and a shorting pin 108.

[0040] In some embodiments, the antenna device 100 can be implemented as a PIFA quarter wavelength antenna to operate as a main radiating patch in NBIOT bands B1 (2100), B3 (1800), B5 (850), B8 (900), B20 (800), B28 (700) with two different lengths: about 110 mm (A+B+C+D+E+F+G+H) for 800 Mhz to 2100 Mhz; and about 120 mm (A+B+C+D+E+F+G+H) for 700 Mhz. It is noted that the slot L, M, Q and the radiating element length P as Figure 1 shown can be derived to improve return loss for the resonant frequencies in the high frequency bands. The position of the RF feed point or feed leg 106 and the shorting plate (ground) or ground leg 108 can be derived to achieve the best results. In addition, the parasitic element 102 can be used to fine-tune the resonant frequencies in the high frequency bands. The parasitic element 102 can be implemented as a passive component that is located in the vicinity of the active radiating element, thereby influencing the antenna performance without the need for a direct electrical connection to the feed line.

[0041] It is noted that, as used herein, the acronym PIFA stands for “Planar Inverted-F Antenna”, which is a type of antenna that can be used in wireless communication devices, such as, for example, mobile phones and other portable electronic devices or field devices. In a PIFA antenna, the radiating element can be implemented as a thin planar structure with a certain shape that resembles the letter “F”. The antenna device 100 (and similarly, the antenna device 101 as Figure 2 shown) can be designed to operate in quarter wavelength, which means that its physical length is about a quarter of the wavelength of the electromagnetic waves it is intended to transmit or receive.

[0042] The "inverted" in the name refers to the antenna being mounted above the ground plane, while "planar" indicates that the antenna lies within a single plane. This design makes PIFA antennas compact, suitable for integration into the limited space available in modern electronic devices. PIFA antennas are known for their high efficiency, low profile, and relatively wide bandwidth.

[0043] Figure 2 A view illustrating an antenna device 101 that can be implemented according to another embodiment is shown. The depicted antenna device 101 is similar to antenna device 100, but with some minor differences. For example, antenna device 101 includes a radiating element comprising a low-frequency radiator 111, which can be configured in an arrangement different from that of low-frequency radiator 110. Figure 1 In the example implementation shown, antenna device 100 may be an NBIOT B3 / B8 / B20 type antenna, while in other cases... Figure 1 In the illustrated example embodiment, antenna device 101 may be an NBIOT B3 / B28 type antenna. For example... Figure 2 Other components of the described implementation scheme are as follows: Figure 1 The components of the illustrated implementation are similar.

[0044] Figure 3 An example is given based on an implementation scheme, such as... Figure 1 This is a view of the antenna assembly 100 located above the PCB ground plane. Figure 3 As shown, the antenna device 100 may also include a plastic substrate 122 and a metal-formed antenna 124. The plastic substrate 122 provides structural support for the antenna device 100 and also manages variations in antenna radiation performance, such as during mass production. The structure of the plastic substrate 122 can be carefully designed to support the radiating elements, thereby minimizing variations, and is secured to the printed circuit board PCB 132 by multiple ribs.

[0045] Figure 4 An example is given based on an implementation scheme, such as... Figure 2 A view depicting the antenna assembly 101 located above the PCB ground plane. (See diagram.) Figure 4 The implementation scheme shown is similar to that of... Figure 3 The illustrated implementation is similar, but the configuration of the metal-formed antenna 124 differs. The antenna assembly 101 can be located and fixed to the PCB 132. Figure 4 The diagram also shows the power supply leg 106 and the short-circuit pin 108.

[0046] Figure 5A perspective view of an antenna assembly 130 is illustrated according to one embodiment, which includes the antenna device 100 along with other metallic components such as a liquid crystal display (LCD) 133, which are disposed together on a printed circuit board 132.

[0047] Figure 6 A perspective view of an antenna assembly 131 is illustrated according to one embodiment, which includes the antenna device 101 along with other metallic components such as an LCD 133, which are disposed on a printed circuit board 132.

[0048] The antenna device 100 and the antenna device 101 demonstrate that precise design considerations such as parasitic elements, resonator length, and introduction of feed points can optimize performance across a range of frequencies. By leveraging the compactness and high efficiency of PIFA technology, the antenna device 101 and the antenna device 101 provide a solution that balances performance, size, and bandwidth requirements, making them well-suited for integration into water meters, ultimately facilitating seamless connectivity in the Internet of Things (IoT) ecosystem.

[0049] Each of the antenna device 100 and 101 is well-suited for integration into a water meter. For example, each of the antenna device 100 and 101 can be designed to be compact and low profile, making them well-suited for installation within the typically cramped confines of a water meter housing. This compact size ensures that they can be easily integrated without adding to the bulk of the water meter.

[0050] Planar inverted-F antennas (PIFAs) are particularly known for their high efficiency in terms of signal transmission and reception. This high efficiency is critical to ensuring the reliability of communication metering devices, where accurate data transmission is necessary for metering and monitoring purposes.

[0051] While designed for narrowband Internet of Things (NBIoT) applications, PIFAs can still provide a relatively wide bandwidth compared to other antenna types. This characteristic enables the antenna to support communication across different frequency bands, which can be necessary for the variety of communication protocols used in metering systems.

[0052] The antenna device 100 and the antenna device 101 can be specifically designed to operate across multiple frequency bands, including those commonly used in NBIoT applications. This flexibility enables it to deploy water metering systems globally, ensuring compatibility with country-specific NBIOT frequency bands.

[0053] As described herein with respect to different embodiments, the introduction of parasitic elements such as the parasitic element 102, along with precise design considerations, allows for fine-tuning of the resonant frequency. This capability is beneficial for optimizing the performance of the antenna across a specific frequency band, while ensuring optimal signal reception and transmission in metering applications (or other applications and devices).

[0054] The subtle differences between the antenna arrangements 100 and 101, such as the arrangement of the low frequency radiators, enable flexibility in design and deployment. This flexibility enables the antenna configuration to be tailored to the specific needs and constraints of different water metering systems.

[0055] Each of the antenna arrangements 100 and 101 can provide a combination of compact size, high efficiency, wide bandwidth, frequency band support, fine tuning capability, and flexibility that makes it well suited for integration into water meters, thereby facilitating reliable and efficient communication in metering and monitoring applications.

[0056] The wideband antenna devices 100 and 101 can be implemented as low-cost wideband antennas with a number of important features. Each of the antenna arrangements 100 and 101 can include a ground layer on a PCB and a plastic substrate made of PC or ABS to support two different metal antenna structures. The wideband antenna devices 100 and 101 can also each include a metal radiating element that can be constructed from, for example, stainless steel or any other metal and can be mounted onto the plastic substrate by, for example, heat staking. Each of the antenna arrangements 100 and 101 can be implemented with a quarter- wavelength antenna structure that is bent to fit into a limited space and slotted to achieve a total radiated power (TRP) of, for example, 18 dBm covering a wideband LTE NB IoT frequency range of, for example, 700 MHz to 2100 MHz.

[0057] Each of the antenna arrangements 100 and 101 includes a wideband antenna arrangement and can include a main radiating element that is above the ground layer and has multiple branches, which can help achieve wideband frequencies. In addition, each of the antenna arrangements 100 and 101 can include a parasitic element that can improve the resonant frequency in a high band of, for example, 1.75 GHz (B3). A feed leg can connect the radiating element to an RF feed port and an impedance matching network, while a shorting pin can connect it to the PCB ground layer.

[0058] The plastic substrate can help control antenna radiation performance variations during mass production. The wideband antenna devices 100 and 101 can be easily assembled with two-point soldering and press-fitting, thereby eliminating the need for RF connectors and related performance issues caused by potting material. The wideband antenna devices 100 and 101 can also be implemented in a way that involves partial potting. That is, the antenna mounting pins can be partially potted to protect the associated radio components and other electronics from harsh environments while maintaining superior radiation performance.

[0059] Based on the foregoing, it can be appreciated that a number of embodiments are disclosed herein, including preferred embodiments and alternative embodiments. For example, in one embodiment, an antenna device can be implemented that can include: an antenna and a plastic substrate that can support at least two different metal structures for the antenna, where the antenna can include a quarter wavelength antenna structure pattern that is curved to fit a limited area and close to metal components and is slotted to achieve transmitter radiated power at wideband frequencies; a radiating element that is mounted above a ground plane and has multiple branches above the ground plane to achieve wideband frequencies; and a parasitic element that can improve resonant frequencies in a high frequency band.

[0060] One embodiment of the antenna device can also include a feed leg and a shorting pin.

[0061] In one embodiment of the antenna device, the feed leg can support a first branch of the radiating element above the ground plane and can electrically couple the first branch to an RF feed port and an impedance matching network.

[0062] In one embodiment of the antenna device, the shorting pin can support a second branch of the radiating element above the ground plane and can electrically couple the second branch to a printed circuit board.

[0063] In one embodiment of the antenna device, the plastic substrate can control antenna radiation performance variations for mass production.

[0064] In one embodiment of the antenna device, the antenna can be directly connected to an RF feed port of an element RF connector to resolve performance issues caused by potting material.

[0065] In one embodiment of the antenna device, the antenna can be partially potted to protect electronics from harsh environmental conditions.

[0066] In one embodiment, an antenna device can include: an antenna and a plastic substrate that supports at least two different metal structures for the antenna, where the antenna includes a quarter wavelength antenna structure pattern that is curved to fit a limited area and close to metal components and is slotted to achieve transmitter radiated power at wideband frequencies; and a radiating element that is mounted above a ground plane and has multiple branches above the ground plane to achieve wideband frequencies.

[0067] In one embodiment, a method of operating an antenna device can involve: achieving transmitter radiated power at a wideband frequency with an antenna and a plastic substrate supporting at least two different metal structures for the antenna, wherein the antenna includes a quarter wavelength antenna structure pattern that is curved to fit a limited area and close to metal components and is slotted to achieve the transmitter radiated power at the wideband frequency; utilizing a radiating element mounted above a ground plane and having multiple branches above the ground plane to achieve the wideband frequency; and utilizing a parasitic element associated with the antenna device to improve resonant frequencies in a high frequency band.

[0068] In some embodiments, the above-mentioned step or operation of utilizing a radiating element mounted above a ground plane and having multiple branches above the ground plane to achieve a wideband frequency can also involve: utilizing the radiating element mounted above the ground plane and having multiple branches above the ground plane to achieve the wideband frequency with a total radiated power of at least 18 dBm in the NBIOT frequency band.

[0069] It should be understood that the variations disclosed above, as well as other features and functions, or alternatives thereof, can be desirably combined into many other different systems or applications. It should also be understood that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein can be subsequently made by others and that such alternatives, modifications, variations or improvements are also intended to be encompassed by the following claims.

Claims

1. An antenna device, the antenna device comprising: an antenna and a plastic substrate supporting at least two different metal structures for the antenna, wherein the antenna comprises a quarter wavelength antenna structure pattern, the pattern is curved to fit a limited area and close to metal components, and is slotted to achieve transmitter radiated power at wideband frequencies; a radiating element mounted above a ground plane and having multiple branches above the ground plane to achieve wideband frequencies; and a parasitic element that improves resonant frequencies in a high frequency band.

2. The antenna device of claim 1, further comprising a feed leg.

3. The antenna device of claim 1, further comprising a shorting pin.

4. The antenna device of claim 1, further comprising a feed leg supporting a first branch of the radiating element above a ground plane and electrically coupling the first branch to an RF feed port and an impedance matching network.

5. The antenna device of claim 1, further comprising a shorting pin supporting a second branch of the radiating element above a ground plane and electrically coupling the second branch to a printed circuit board.

6. The antenna device of claim 1, wherein the plastic substrate controls antenna radiation performance variations for mass production.

7. The antenna device of claim 1, further comprising an antenna that resolves performance issues caused by potting material with an RF feed port connected directly to an element RF connector.

8. The antenna device of claim 1, further comprising an antenna that is partially potted to protect electronics from harsh environmental conditions.

9. The antenna device of claim 1, further comprising: a feed leg supporting a first branch of the radiating element above a ground plane and electrically coupling the first branch to an RF feed port and an impedance matching network; and a shorting pin supporting a second branch of the radiating element above a ground plane and electrically coupling the second branch to a printed circuit board.

10. The antenna device of claim 9, wherein the plastic substrate controls antenna radiation performance. ​ ​

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