The present invention relates to an antenna assembly and a wireless electronic device comprising said antenna assembly.
Electronic wireless devices including mobile telephones, tablets set-top boxes and gateway devices contain an increasing number of electronic components in an increasingly reduced space.
An important functional element of such wireless devices is the antenna for transmission and reception of radio frequency waves. The optimum place for positioning an antenna is at the front of the wireless device. However, the presence of the many other electronic components at the front of a wireless device creates obstacles to the radiation of radio waves and impairs the performance of the antenna. Moreover, in some configurations large areas of ground clearance need to be provided on the circuit board to provide appropriate grounding of the antenna. Because of the presence of the other electronic components it is becoming increasingly difficult to find the required space for ground clearance of antennas at the front side of the circuit board.
The present invention has been devised with the foregoing in mind.
A first aspect of the invention provides an antenna assembly mountable on a circuit board, the antenna assembly comprising: a radiating part; a transmission part for feeding the radiating part, the transmission part comprising a signal feed element and a ground element connectable to the circuit board; wherein the ground element comprises a first ground portion extending in a longitudinal direction alongside the signal feed element and an extension ground portion extending laterally from the first ground portion, the extension ground portion being folded to form a ground plane extending over both the signal feed element and the first ground portion and spaced apart from the signal feed element, the extension ground portion being connectable to a ground connection of the circuit board.
In an embodiment the first ground portion and the extension ground portion are formed as a single grounding unit.
In an embodiment, the signal feed element and the first ground portion extend parallel to one another.
In an embodiment, the signal feed element operates in a microstrip mode.
In an embodiment, the signal feed element is fed by a coplanar waveguide with ground.
In an embodiment the extension ground element is folded to provide a ground plane on each side of the signal feed element.
In an embodiment, a transmission line interface is provided for connecting the signal feed element to the circuit board, wherein an aperture is defined in the extension ground portion at the part of the extension ground portion facing towards the transmission line interface.
In an embodiment, the radiating element comprises an Inverted F Antenna.
In an embodiment, the radiating part comprises a ground element extending from the first ground portion of the transmission part and a signal element extending from the signal feed element of the transmission part and a radiating element extending perpendicularly to the ground element and the signal element.
In an embodiment, the radiating element is folded along its longitudinal axis.
In an embodiment, the radiating element comprises a monopole type antenna
In an embodiment, the extension ground portion is folded along a further axis such that it extends parallel to the ground element and the signal element of the radiating element.
In an embodiment, the ground extension portion is located on an opposite side of the signal feed element and the first ground portion of the transmission part, to the radiating element.
In an embodiment, the ground extension portion is located on the same side of the signal feed element and the first ground portion of the transmission part, as the radiating element.
In an embodiment the radiating element is a monopole. In another embodiment the radiating element is a dipole.
In an embodiment the transmission part is configured to adapt the impedance of the radiating part. For example, the impedance of the radiating part is adapted to match the input impedance of the transmission part. In one embodiment the height of the transmission part is set to a quarter wavelength.
Another aspect of the invention provides an antenna assembly mountable on a circuit board, the antenna assembly comprising: a radiating part; a transmission part for feeding the radiating part, the transmission part comprising a signal feed element and a ground element connectable to the circuit board; wherein: the ground element comprises a first ground portion extending alongside the signal feed element and a ground plane extending over both the signal feed element and the first ground portion and spaced apart from the signal feed element, the ground plane being connectable to a ground connection of the circuit board.
The first ground portion and the ground plane may be formed as a single grounding unit.
A second aspect of the invention provides an electronic communication device comprising a circuit board and an antenna assembly according to any preceding claim mounted on the circuit board, the antenna assembly being mounted such that the a signal feed element and a first ground portion of the transmission part extend away from the surface of the circuit board.
In an embodiment, the circuit board is provided with at least one electronic component at the front of the circuit board and the radiating part is arranged to extend from the transmission part beyond the electronic component to the front of the electronic component and to face outwards from the electronic communication device, the transmission part being disposed behind the electronic component.
In an embodiment, the electronic comprises at least one of a display board, an LED, an infra-red sensor, a control unit, and a USB connector.
In an embodiment, the circuit board comprises a clearance area devoid of electronic components, the clearance area being disposed behind the antenna assembly.
In an embodiment, the electronic communication device is a gateway device or a set top box.
A further aspect of the invention provides an antenna assembly mountable on a circuit board, the antenna assembly comprising: a radiating part; a transmission part for feeding the radiating part, the transmission part comprising a signal feed element and a ground element connectable to the circuit board; wherein the ground element comprises an extension ground element, folded away from the ground element such that it extends from the ground element over the signal feed element and the ground element to form a ground plane spaced apart from the signal feed element and connectable to a ground connection of the circuit board.
Embodiments of the invention will now be described, by way of example only, and with reference to the following drawings in which:
The transmission part 200 comprises a signal feed element in the form of a signal strip 210 for feeding signals from the PCB to the radiating part 100 and a ground element comprising ground strip 220 connectable to a ground connection of the PCB. The signal strip 210 and the ground strip 220 are arranged to extend parallel to one another. The ground strip 220 forms a first ground portion extended by an extension ground portion in the form of extension ground element. The extension ground element extends laterally from one side of the ground strip 220 and is curved through an angle of approximately 180° to form a ground plane 230 parallel to and spaced apart from the main surfaces of the ground strip 220 and the signal element 210. The ground plane 230 is connectable to a ground connection of the PCB. In this configuration the signal strip 210 is in a microstrip mode with a finite ground plane provided by ground plane 230.
An aperture 236 is defined in the ground plane 230 at the part of the ground plane 230 facing the interface between the signal strip 210 and the PCB. This enables electrical contact between the ground plane 230 and the feeding line of the PCB to be avoided. The signal strip 210 is provided with a pin 211 for connecting to a corresponding connection on the signal feeding line of the PCB. The ground strip 220 is provided with a pin 221 for connecting to a corresponding connection on the ground plane of the PCB, and the extension ground plane 230 is provided with a pin 231 for connecting to a corresponding connection on the ground plane of the PCB.
The radiating part 100 comprises a signal strip 110 extending from the signal strip 210 of the transmitting part, and a ground strip 120 extending from the ground strip 220 of the transmitting part. The signal strip 110 and the ground strip 120 are bent at an angle of approximately 90° to the signal strip 210 and the ground strip of the transmitting part. A radiating strip 140 connects the ends of the signal strip 110 and the ground strip 120 to form an IFA type antenna. The radiating strip 140 is folded along its longitudinal axis by an angle of approximately 90°. Such a configuration enables the antenna input impedance matching to be optimized.
The transmission part 200 may also serve as an impedance matching line. The transmission part 200 may adapt the impedance of the antenna part 100 to its input impedance. In one particular embodiment the height of the transmission part may correspond to a quarter wavelength. The height of the transmission part is determined by the length of the signal strip 210 and ground strip 220.
The signal strip 210 and the ground strip 220 of the transmission part 200 of the antenna assembly 10 extend from the surface of the PCB board 300. The radiating part 100 of the antenna assembly 200 is thereby raised a height above the surface of the PCB board 300, the height being dependent upon the length of the signal strip 210 and the ground strip 220 of the transmission part 200. The clearing height enables the radiating part 100 to be disposed above an electronic component fitted on the PCB board 300 in front of the transmission part 200 which would otherwise act as an obstacle to radiation of the radiating strip 140. The extension of the signal strip 110 and the ground strip 120 at a right angle from the signal strip 210 and the ground strip 220 of the transmission part 200 enables the radiating strip 140 to extend beyond the electronic component thereby providing an obstacle free zone in front of the radiating strip 140.
The radiating part 8100 comprises a signal strip 8110 extending from the signal strip 8210 of the transmitting part, and a ground strip 8120 extending from the ground plane 8230 of the transmitting part. The signal strip 8110 and the ground strip 8120 are bent at an angle of approximately 90° to the feed line strip 8210 and the ground plane 8230 of the transmitting part. A radiating strip 8140 connects the ends of the signal strip 8110 and the ground strip 8120 to form an IFA type antenna. The radiating strip 8140 is folded along its longitudinal axis by an angle of approximately 90°.
Embodiments of the invention enable the ground clearance surface area on the PCB to be drastically reduced, freeing more space for the integration of other components. Any obstructions and obstacles placed in the front side of a main board, such as a barrier of LEDS and mechanical push-buttons, a display board or other plastic and metal parts, can be by-passed implementing an antenna assembly according to embodiments of the invention enabling thus an improved radiation performance of the antenna.
Moreover the antenna assembly according to embodiments of the invention can be manufactured at reduced cost, using common manufacturing technologies, for example by stamping process.
In addition an antenna assembly according to embodiments of the invention can be placed not only at the edge of a PCB but towards the inner part of the PCB, close to RF transceiver output, thereby reducing insertion losses by virtue of the transmission line being integrated with the antenna assembly in a single metal part. The integrated transmission line may also serve as an impedance matching line, avoiding the need to provide impedance matching on the main board using printed transmission line or lumped components (inductors, capacitors).
The antenna assembly according to embodiments of the invention may operate as a monopole or a dipole.
Although the present invention has been described hereinabove with reference to specific embodiments, the present invention is not limited to the specific embodiments, and modifications will be apparent to a skilled person in the art which lie within the scope of the present invention.
For instance, while the foregoing examples have been described with respect to a set top box it will be appreciated that the invention may be applied to any other wireless electronic communication device employing an antenna.
Many further modifications and variations will suggest themselves to those versed in the art upon making reference to the foregoing illustrative embodiments, which are given by way of example only and which are not intended to limit the scope of the invention, that being determined solely by the appended claims. In particular the different features from different embodiments may be interchanged, where appropriate.
Number | Date | Country | Kind |
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14306372.5 | Sep 2014 | EP | regional |
14306755.1 | Nov 2014 | EP | regional |