PCB ANTENNA

Abstract

An antenna (200) comprises an antenna body (212). The antenna body is integrally formed as a part of a PCB (210) and the antenna body is enclosed by metal. The antenna body may be enclosed by printed or plated metal on both top and bottom surfaces of the PCB and by edge plated metal along the circumference of the antenna body.

Claims

1. An antenna comprising an antenna body formed by a Printed Circuit Board, PCB, material, wherein the antenna body is integrally formed as a part of the PCB, and the antenna body is enclosed by printed or plated metal on both top and bottom surfaces of the PCB and by edge plated metal along the circumference of the antenna body.

2. The antenna according to claim 1, wherein the antenna body extends out from an edge of the PCB.

3. The antenna according to claim 1, wherein the antenna body is surrounded by PCB material with an air gap between the majority of the circumference of the antenna body and the surrounding PCB.

4. The antenna according to claim 1, wherein the antenna is configured for any one of Bluetooth, Bluetooth Low Energy, BLE, Global Position System, GPS, Wireless Speaker & Audio, WISA, Zigbee, Z-wave and Wireless Local Area Network, WLAN, applications.

5. The antenna according to claim 1, wherein the antenna body has an F-shape.

6. A Printed Circuit Board, PCB comprising an antenna according to claim 1.

7. A transceiver comprising an antenna according to claim 1.

8. A wireless data acquisition device comprising a transceiver according to claim 7.

9. The wireless data acquisition device according to claim 8 comprising any one of a camera, a Physical Access Control System, PACS, controller, a network video recorder, a home automation device, a data logger.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Examples of embodiments will be described in more detail with reference to attached drawings in which:

[0020] FIG. 1 is a PCB antenna according to prior art;

[0021] FIG. 2a is a top view of a PCB with an antenna according to embodiments herein;

[0022] FIG. 2b is a schematic perspective view of a part of the PCB with the antenna shown in FIG. 2a;

[0023] FIG. 3 is a schematic view illustrating a PCB antenna according to embodiments herein; and

[0024] FIG. 4 is a block diagram illustrating a wireless data acquisition device in which an antenna according to embodiments herein may be implemented.

DETAILED DESCRIPTION

[0025] FIG. 2a is a top view of a PCB 210, where one example embodiment of a PCB antenna 200 is shown. The PCB antenna 200 comprises an antenna body 212 integrally formed as a part of the PCB 210. In this example, the antenna 200 is designed to be a dual band antenna for 2.4 GHz and 5 GHz. The antenna body 212 has an F-shape extending approximately 16 mm out from the edge of the remaining PCB and being about 22 mm across. It should be noted that with another design and choice of shape, the antenna will have other dimensions. The antenna body 212 is cut out from the PCB along a majority of its circumference except at two ends 214, 216, where it extends from the rest of PCB 210. The antenna body 212 is enclosed in or embedded by metal, e.g., copper. This may be done using various processes. According to some embodiments herein, the antenna body 212 is enclosed by plated or printed metal on both top and bottom surfaces of the PCB 210 and by edge plated metal along the circumference of the antenna body 212.

[0026] FIG. 2b shows a perspective view of the antenna body 212. Typically there is already a printed or plated metal layer or metal traces on the top and bottom surface of the PCB, so both top and bottom surfaces 221, 222 of the antenna body 212 are covered by metal. When cutting out the antenna body 212, the cutting edge of the antenna body 212 is exposed to air. To enclose the antenna body 212, the cutting edge of the antenna body 212 may be edge plated by metal, e.g., copper. As shown in FIG. 2b, the edge of the antenna body 212 is plated by metal along the circumference of the antenna body which is separate from the PCB, where the edge marked with 218, 219 is visible. Edge plating the antenna body is a normal process that is done when, e.g., edge plating a via-hole. When the cutting edge is closed by edge plated metal, the antenna body 212 is enclosed by metal. This essentially turns the antenna body 212 into a solid metal part, even though it is integral with the rest of the PCB 210. Therefore, the antenna body 212 becomes a three-dimensional (3D) structure and can achieve three-dimensional exposure to free space, similar to a wire antenna, which means it may have great performance and RF range. Further, in this embodiment, the antenna body 212 extends out from an edge of the PCB 210, as shown in FIGS. 2a and 2b. This has the advantage of providing free space around the antenna body.

[0027] To save space and use available PCB area efficiently, according to some embodiments herein, the antenna body may be arranged on a PCB 310 as shown in FIG. 3. A PCB antenna 300 comprises an antenna body 312. The antenna body 312 is surrounded by PCB material with an air gap 320 between the majority of the circumference of the antenna body 312 and the surrounding PCB 310. The antenna body 312 extends from the rest of the PCB 310 at ends 314, 316. In this way, the antenna body 312 forms a “peninsula” in the PCB 310 with a “moat” around it, and the antenna body 312 is essentially isolated from the rest of PCB 310 and the surrounding PCB 310. Therefore the rest of and the surrounding PCB will not influence the RF properties of the antenna 300. The antenna body 312 is enclosed by metal in the same way as for the antenna body 212 described above and illustrated in FIGS. 2a and 2b. In this embodiment, the antenna body 312 has an inverted F-shape. On the surrounding PCB, some components may be located so that available PCB area is used efficiently. Further, since the antenna body 312 is located inside the PCB and does not extend out from the PCB 310, no extra space is needed for the antenna 300.

[0028] Although the antenna bodies 212, 312 in the two example embodiments have an F-shape and inverted F-shape, the antenna body 212, 312 may be configured to have any kind of shape depending on the type of antenna and space constraints, such as a straight line shape, an L-shape, a meander shape, a meandered inverted F-shape, a circular shape, a curve with wiggles shape, etc.

[0029] The design parameters, e.g., the metal width on the top and bottom surfaces of the antenna body 212, 312, the antenna length, the antenna feed connection etc., which determine the antenna radiation impedance, frequency selectivity, bandwidth and centre frequency, will require the same considerations as a conventional PCB antenna with respective shapes as mentioned above. However, the design of the antenna 200, 300 according to embodiments herein does not need to be tuned or changed and may be applied for various PCBs with different thickness and relative dielectric constant since the antenna body 212, 312 is enclosed by metal and isolated from the rest of PCB. That is, the design considerations are the same as for the normal PCB antenna, but without having to take the varying properties of the PCB material into account.

[0030] Since the antenna 200, 300 according to embodiments herein is integrally formed as a part of the PCB 210, 310, it may be conveniently and directly connected to other components on the PCB 210, 310, such as feeding port, transmission line, impedance matching network, antenna switch, filter, etc. on the same PCB by metal trace, e.g., by the same metal trace on the surface or bottom of the antenna body 212, 312, with no need for extra parts or components. It is also easy to impedance match to target impedance. For a transceiver, the target impedance may, e.g., be 50 Ω.

[0031] The antenna 200, 300 according to embodiments herein may be configured for any one of Bluetooth, BLE, GPS, WISA, Zigbee, Z-wave and WLAN applications, and suitable for 2-10 GHz radio operation frequency.

[0032] The antenna 200, 300 according to embodiments herein is suitable for any wireless communication device, or for any electronic device which needs an antenna. FIG. 4 shows a wireless data acquisition device 400 in which the antenna 200, 300 according to embodiments herein may be implemented. The wireless data acquisition device 400 may be any one of a camera, such as a monitoring camera, a PACS controller, a network video recorder, a home automation device, a data logger etc. The wireless data acquisition device 400 comprises a PCB 410, a transceiver 412 which uses the antenna 200, 300 according to embodiments herein. The wireless data acquisition device 400 may comprise other units, e.g., a memory 420 and a processing unit 430 for information storage and signal processing etc. The memory 420 and processing unit 430 may be located on the same PCB 410 as the antenna 200, 300.

[0033] To summarise, some advantages of the antenna 200, 300 according to embodiments herein include:

[0034] First, the PCB material which forms the antenna body 212, 312 is completely enclosed or surrounded by the metal and therefore will not influence the properties of the antenna.

[0035] Second, the antenna body 212, 312 is essentially isolated from the rest part of PCB and the surrounding PCB, therefore the rest part of the PCB and the surrounding PCB will not influence the properties of the antenna.

[0036] Third, the antenna 200, 300 may be conveniently and directly connected to other components on the same PCB by metal trace without extra parts or components.

[0037] Fourth, the antenna 200, 300 according to embodiments herein can achieve great performance and RF range.

[0038] Fifth, the antenna 200, 300 according to embodiments herein uses fewer parts, takes less space and vertical height.

[0039] Sixth, the antenna 200, 300 according to embodiments herein does not need to be adjusted or changed and may be applied for various PCBs with different thickness and relative dielectric constant.

[0040] Further, no extra manufacturing process is needed to make the antenna 200, 300 according to the embodiments herein, which means no extra cost.

[0041] When using the word “comprise” or “comprising” it shall be interpreted as non-limiting, i.e. meaning “consist at least of”.

[0042] The embodiments herein are not limited to the above described preferred embodiments. Various alternatives, modifications and equivalents may be used. Therefore, the above embodiments should not be taken as limiting the scope of the invention, which is defined by the appending claims.