Communication device with embedded antenna

A communication device with an embedded antenna includes a printed circuit board and an embedded antenna including at least one radiating unit, at least one feeding unit, where each feeding unit is coupled to a corresponding one of the at least one radiating unit and the printed circuit board, and a connecting unit coupled to the at least one radiating unit including a first connecting portion and a second connecting portion. The connecting unit and the at least one radiating unit form a loop structure such that the embedded antenna is capable of covering one side of the printed circuit board.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. 119 from TAIWAN Application No. 098135751 filed on Oct. 22, 2009, the contents of which are incorporated herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a communication device with an embedded antenna, and more particularly, to a communication device with an embedded antenna capable of covering a printed circuit board of the communication device and going through the surface mount technology procedure with the printed circuit board.

2. Description of the Prior Art

Wireless communication network is a dominant channel for communication and data transmission in modern society. Wireless communication devices, such as cell-phones, PDAs, and wireless USB dongles, have become more and more popular and are developed toward minimization. Also, the manufacture process of the wireless communication device is simplified to decrease the cost and enhance the productivity. In the composition of a wireless communication device, besides a printed circuit board, an antenna is another unit with larger volume, in which field an embedded antenna formed by metal plates have become one of the mainstream, to facilitate the flexibility of appearance of the wireless communication device and meet the need for portability at the same time.

Electronic units connect to the printed circuit board through the automatic surface mount technology procedure. However, the embedded antenna of the prior art is not a surface mounted unit, and hence cannot be assembled through the surface mount technology procedure, but through an additional assembling process instead. There are two assembling methods of the embedded antenna of the prior art. One is manually welding the antenna onto the printed circuit board after the surface mount technology procedure is performed to the printed circuit board; the other is installing the antenna on the shell of the wireless communication device such that the antenna contacting the contact spring on the printed circuit board. The above two assembling methods of the embedded antenna cost more, and the manual assembling process easily causes instability of antenna characteristics. In addition, the total height of wireless communication devices formed according to the above assembling methods are roughly determined by the height of printed circuit board plus the height of embedded antenna, hence only limited amount of height can be saved.

From the above, the embedded antenna according to the prior art needs additional assembling process, and thereof results in an increase of the production cost of the wireless communication device. It must be improved to reach the goal of minimization and high productivity.

SUMMARY OF THE INVENTION

It is therefore a primary objective of the claimed invention to provide a communication device with an embedded antenna.

The present invention discloses a communication device with an embedded antenna comprising a printed circuit board and an embedded antenna, which comprises at least one radiating unit, at least one feeding unit, wherein each feeding unit is coupled to one of the at least one radiating unit and the printed circuit board, and a connecting unit, coupled to the at least one radiating unit, comprising a first connecting portion and a second connecting portion. The connecting unit and the at least one radiating unit form a loop structure such that the embedded antenna is capable of covering one side of the printed circuit board.

DETAILED DESCRIPTION

Please refer toFIG. 1.FIG. 1is a schematic diagram of a communication device10according to an embodiment of the present invention. The communication device10can be a cell-phone, a PDA, or a wireless USB dongle, and comprises a printed circuit board11and an embedded antenna12. The printed circuit board11is used to realize the functionalities of the communication device10, which may comprise a radio frequency (RF) circuit, a modulation/demodulation circuit, etc., according to system requirements. The embedded antenna12is an antenna compatible of the 2T2R system, by which the communication device10realizes the application of two transmitters and two receivers. In addition, inFIG. 1, the printed circuit board11and the embedded antenna12are not yet combined. It can be referred toFIG. 2A,FIG. 2B, andFIG. 3for detailed descriptions.

First,FIGS. 2A and 2Bare the top view and the bottom view of printed circuit board11ofFIG. 1respectively. The top layer and the bottom layer of the printed circuit board11are the placing areas of electronic units of communication device10, while a ground plane located in one of multiple layers of the printed circuit board11. On one side of the top layer and the bottom layer of the printed circuit board11metal areas A-D are placed, marked by oblique lines. The metal areas A-D are copper exposure areas, not covered with insulating paint in the manufacture process of printed circuit board11, wherein the metal areas A and B are the feeding points of signals. The metal areas C and D are located in the top layer and the bottom layer of the printed circuit board11respectively, and the metal areas A and B are located in the same layer with the metal area C. Next, please refer toFIG. 1andFIG. 3at the same time.FIG. 3is a plan expanded view of the embedded antenna12. The embedded antenna12is the combination of two planner inverted-F antennas (PIFA), formed by metal plates, which comprise radiating units120A and120B, feeding units122A and122B, a connecting unit124, fixing units130and132, and blocking units134and136.

The radiating unit120A and120B are utilized for radiating the RF signals generated from the circuits on printed circuit board11to air, and receiving RF signals of different frequencies from air. The radiating unit120A is apart from the radiating unit120B by more than a distance w, the length of one side of printed circuit board11. Please note that the shape of both radiating unit120A and120B shown inFIG. 1is merely an embodiment of the present invention, the present invention is not limited to the shape of both radiating units120A and120B. The feeding unit122A is coupled to the radiating unit120A, and comprises a blocking portion F1; the feeding unit122B is coupled to the radiating unit120B, and comprises a blocking portion F2; the blocking portion F1and the blocking portion F2are fillisters formed through the pressing in the manufacture process of the embedded antenna12. The feeding unit122A and the feeding unit122B are used for feeding the RF signals generated from circuits on the printed circuit board11to the radiating unit120A and radiating unit120B respectively, and passing the RF signals received by the radiating unit120A and the radiating unit120B to the circuits on the printed circuit board11.

The connecting unit124comprises a connecting portion126and a connecting portion128. Two ends of the connecting portion126are coupled to the radiating unit120A and120B respectively, wherein one end comprises a blocking portion F3and the other end comprises a blocking portion F4. Two ends of the connecting portion128are also coupled to the radiating unit120A and120B, wherein one end comprises a blocking portion F5and the other end comprises a blocking portion F6. The connecting portion126, the connecting portion128, the radiating unit120A and the radiating unit120B form a loop structure. The connecting portion126and the connecting portion128are parallel and apart by at least a distance H equal to the height of the printed circuit board11, making the loop structure capable of covering one side of the printed circuit board11in a tolerable range of manufacturing errors.

The fixing unit130is coupled to the connecting portion126, and is in the same plane with the connecting portion126. The fixing unit132is coupled to the connecting portion128, and is in the same plane with the connecting portion128. Please note that the embedded antenna12is a planner inverted-F antenna (PIFA), therefore, at least one of the fixing unit130and the fixing unit132must be coupled to the ground plane of the printed circuit board11. The blocking unit134and the blocking unit136are both coupled between the connecting portion126and the connecting portion128, and are utilized for positioning. The plane of the blocking unit134and the blocking unit136is perpendicular to the plane of the connecting portion126or the connecting portion128. When the embedded antenna112covers one side of the printed circuit board11, due to the existence of the blocking unit130and the blocking unit132, the printed circuit board11is unlikely to deviate from a predetermined position; thereof, the feeding unit122A and the feeding unit122B are capable of connecting with the metal area A and the metal area B of the printed circuit board11in a precise location, respectively. Also, the fixing unit130and the fixing unit132can also connect with the metal area C and the metal area D of the printed circuit board11in a precise location, respectively. At least one of the metal area C and the metal area D is coupled to the ground plane of the printed circuit board11.

Moreover, the blocking portions F1and F2of the feeding units122A and122B, and the blocking portions F3, F4, F5, and F6of the connecting portions126and128are also utilized for positioning, to keep the radiating unit120A and120B apart from the printed circuit board11by a distance G, for avoiding the interference caused from the noise of the periphery ground plane of the printed circuit board11to affect the RF signals transmitted by the radiating unit120A and120B. Please note here, the objectives of the blocking portions F1-F6are used to keep the printed circuit board11a distance apart from the radiating units120A and120B. In another example, the above blocking units are coupled to the connecting portions, for aligning the at least one feeding unit with at least one metal area of the printed circuit board when the embedded antenna covers one side of the printed circuit board. Physical forms of the blocking portions F1-F6are not limited in the present invention; that is, it can be fillisters as illustrated inFIG. 1or dimples also formed in the manufacture process of the embedded antenna12, in other embodiments of the present invention.

Therefore, the loop structure, formed by the connecting unit124, the radiating unit120A, and the radiating unit120B, together with the blocking unit134and the blocking unit136, constitute a cap-like structure, making the embedded antenna12capable of covering one side of the printed circuit board11. After performing the solder paste printing process of the surface mount technology procedure on the printed circuit board11, the embedded antenna12is mounted on the printed circuit board11by an assembling step. Next, the automatic component placement procedure is performed on the printed circuit board11with the embedded antenna12. Last, the embedded antenna12and the printed circuit board11pass the reflow process together. As a result, the feeding unit122A and the feeding unit122B are fixed and electrically connected onto the metal area A and the metal area B of the printed circuit board11respectively, and the fixing unit130and the fixing unit132are also fixed to the metal area C and the metal area D respectively. In other words, the embedded antenna12is fixed onto the printed circuit board11through the surface mount technology procedure.

In brief, according to the design of the embedded antenna12inFIG. 1, only one step needs to be added to the assembling process of the communication device10, i.e. making the embedded antenna12covering one side of the printed circuit board11before the automatic component placement procedure, and it resembles assembling two antennas at the same time. The prior art embedded antenna compatible of the 2T2R communication device must be manually welded twice; by contrast, the assembling process of the embedded antenna12of the communication device10is simpler. In the meanwhile, it decreases the possible errors caused by manual welding, and excessively enhances the yield rate. In addition, it can be shown inFIG. 1that the embedded antenna12combines, as a cap, with the printed circuit board11, so that the radiating unit120A and the radiating unit120B of the embedded antenna12are located in the both sides of the printed circuit board11. Therefore, the height of the communication device10is mainly determined based on the embedded antenna12. For example, if the height of the embedded antenna12is 4 millimeters and the height of the printed circuit board11is 2 millimeters, the total height of the communication device10, shells not included, would be 4 millimeters, wherein the height of the printed circuit board11is overlapped and absorbed by the height of the embedded antenna12and is hence involved. Under the same conditions, the total height of the prior art communication device is the height of the printed circuit board plus the height of the embedded antenna, which equals 6 millimeters. By contrast, the embodiment according to the present invention minimizes the height of the communication device, which is an advantage for appearance of communication device.

In addition, it can be shown inFIG. 3that the embedded antenna12can be manufactured in a monolithic way. All units of embedded antenna12are in fact formed by a single integrated bent metal plate. As a result of the monolithic antenna, the connecting portion128is further divided into128L and128R; the fixing unit132is also divided into132L and132R, which are all electrically connected to the metal area C of the printed circuit board11through the surface mount technology procedure. Please note that the communication device10is merely an embodiment according to the present invention, and can be varied and modified accordingly by those skilled in the art. The monolithic embedded antenna12illustrated inFIG. 3is merely one realization of the antenna12for simplifying the production process, and the present invention is not limited to it. The embedded antenna12can also be formed by assembling a plurality of metal plates. In the embodiments according to the present invention, the forms, the numbers, and the locations of radiating units, fixing units, blocking units and fillister blocking portions of embedded antenna12can all be designed and modified to fit the system requirements.

Please refer toFIG. 4toFIG. 7, which are schematic diagrams of communication devices40,50,60, and70according to embodiments of the present invention. Each communication device is a variation embodiment of the communication device10ofFIG. 1, and is also formed by assembling a printed circuit board and an embedded antenna. The functionalities and connecting relations of units of the communication devices40,50,60and70can be derived based onFIG. 1and the above descriptions, and are not detailed narrated herein. Hereinafter, only the differences will be depicted. InFIG. 4, the embedded antenna of the communication device40does not include a blocking unit. Before performing the automatic component placement procedure of the surface mount technology procedure to the printed circuit board, a fixture can be used to replace the blocking unit, making the embedded antenna cover the printed circuit board and a feeding unit422A, a feeding unit422B, and a fixing unit430of the embedded antenna can connect with the corresponding metal areas of the printed circuit board in precise positions. Therefore, the surface mount technology procedure can be performed to assemble the embedded antenna on the printed circuit board without an additional manual welding step. Moreover, there is only one fixing unit of the embedded antenna of the communication device40, since the feeding unit422A and the feeding unit422B are not only the feeding point of signals, but also providers of the fixed function, i.e. they connect with the printed circuit board by solder paste.

InFIG. 5, a printed circuit board51of the communication device50is different from the printed circuit board11of the communication device10. The ground plane of the printed circuit board51is a predetermined distance apart from both sides of the printed circuit board51, equals the distance G inFIG. 1; the width of the printed circuit board51, W′, is larger than the width of the printed circuit board11, W. In other words, there is a clearance area around the sides of the printed circuit board51. An embedded antenna52of the communication device50comprises merely one fixing unit and one blocking unit, such as a fixing unit530and a blocking unit534inFIG. 5. No fillister blocking portion is set on the feeding unit and the connecting portion because the distance G, by which the ground plane of the printed circuit board51is apart from the sides of the printed circuit board51, is long enough to avoid the interference caused from the noise on the ground plane to affect the RF signals transmitted by the radiating units of the embedded antenna, and hence no fillister blocking portion is needed to keep the printed circuit board51and the radiating units of the embedded antenna apart. In addition, by adequately designing the size and location of the blocking unit534, even the embedded antenna52comprises only one blocking unit, the functionality of positioning the printed circuit board51can also be fulfilled.

In the above embodiments, the embedded antennas take the antennas compatible in the 2T2R system as examples, whereas in practice, the number of antenna of present invention is not limited to specific one; it can be only one or upward two. For example, inFIG. 6, an embedded antenna62is a single planar inverted-F antenna. In spite that the embedded antenna62comprises merely a radiating unit620, a connecting portion626and a connecting portion628of a connecting unit624of the embedded antenna62together with a radiating unit620still form a loop structure, and further form a cap-like structure with blocking units634and636. Therefore, the embedded antenna62is capable of covering one side of a printed circuit board61of the communication device60, and then the automatic component placement procedure and the reflow procedure of the surface mount technology procedure are performed on the printed circuit board61with the embedded antenna62. Those skilled in the art can make alternations and modifications to the embedded antenna62according to the above embodiment, such as reducing the number of fixing unit or blocking unit to one, or altering the design of the ground plane of printed circuit board and canceling the fillister blocking portions, and is not narrated herein.

Please note that the embedded antennas inFIG. 1toFIG. 6take planar inverted-F antenna antennas as examples, however, the embedded antenna of the embodiment according to the present invention is not limited to the planar inverted-F antenna, monopole antenna, or antenna of other types are also included. For example, inFIG. 7, an embedded antenna72of the communication device70is the combination of two monopole antennas, and the form of radiating units720A and720B of the embedded antenna72is different from the form of the radiating units120A and120B inFIG. 1. In addition, since the embedded antenna72is the combination of monopole antennas, fixing units of the embedded antenna72need not to connect to the ground plane of printed circuit board. Those skilled in the art can make alternations and modifications to the embedded antenna72according to the above embodiment, and is not narrated herein.

To sum up, in the communication devices of embodiments according to the present invention, the printed circuit boards are designed corresponding to the embedded antenna, hence, only one step needs to be added to the assembling process of the communication device, i.e. making the embedded antenna cover one side of the printed circuit board before the automatic component placement procedure, so that the automatic component placement procedure and the reflow procedure are performed on the printed circuit board with the embedded antenna. Therefore, the high assembling cost and the instability of antenna characteristics owing to the manual welding process in the assembling process of the prior art communication device can be avoided. In addition, the embedded antennas of embodiments according to the present invention not only are easier to assemble, but also enable overlaps in the space occupied by the embedded antennas and the printed circuit boards to get minimized heights of the communication devices.