Abstract:
A headset for a mobile communication terminal is disclosed. The headset comprises a main body and a RF module printed circuit board (PCB) housed within it. A microphone is also housed within the main body and connected to the RF module PCB. A guide piece housing an antenna, which is connected to the RF module PCB, is connected to the main body on one end and has an opening on the second end. Finally, a speaker is connected to the main body opposite the guide piece.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   Pursuant to 35 U.S.C. § 119(a), this application claims the benefit of earlier filing date and right of priority to the Korean Patent Application No. 2002-20245, filed on Apr. 4, 2002, the content of which is hereby incorporated by reference in its entirety. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a headset used for a mobile communication terminal and, more particularly, to a compact and portable antenna mounted inside a communication headset. 
   2. Description of the Background Art 
   In general, a radio earphone-microphone for a mobile communication terminal, or the like, is connected to the terminal by way of a wire. Korea Patent Application No. 2000-38718, dated Jul. 6, 2000, discloses a conventional radio earphone-microphone that includes a parent device connected to a mobile communication terminal and a child device wirelessly connected to the parent device. A transmission antenna and a reception antenna are installed inside a support bar in the child device. 
   The transmission and the reception antenna are installed close to the inside of the support bar. The transmission power flows from the transmission antenna to the reception antenna, resulting in performance degradation of the overall system due to interference between the transmission antenna and the reception antenna. 
   Distortion and performance degradation also occur when a microphone is installed at an end portion of the antenna, because a voice signal generated by the microphone is transmitted as a module by using an electric wire passing around the antenna. This results in reception being deteriorated due to a back current of the signal and interference. Furthermore, due to an impedance change, the antenna may not function properly. 
     FIG. 1  is a perspective view of a chip design with the antenna installed on a radio frequency (RF) module. Antenna  104  is mounted as an integrated circuit on a printed circuit board (PCB)  102  of a module of a mobile communication terminal. That is, in this structure, a dipole or a helical antenna is mounted on the surface of the PCB  102  by using a dielectric substance having a high dielectric constant. The dielectric constant of the dielectric substance is very high to provide for a very short wavelength and thus, a compact terminal. Due to the high dielectric constant, a power loss takes place. Also, the transmission characteristics and the gain of the antenna can be degraded. 
     FIG. 2  is a perspective view of a print-type monopole antenna installed on a PCB module of a mobile communication terminal. A monopole antenna  108  printed on the module PCB  106  is inexpensive. However, since a certain distance should be maintained from a ground plane, and since the dielectric constant of the substrate is small, module integration is difficult. Moreover, if the antenna is positioned close to the RF module, it would be susceptible to noise generated from the module. As such, the transmission properties of the antenna are degraded. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to an antenna mounted inside a preferably wireless headset for a mobile terminal. 
   Additional features and advantages of the invention will be set forth in the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
   To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, an antenna mounted inside a headset for a mobile communication terminal comprises a main body having first and second ends and a RF module printed circuit board (PCB) housed within the main body. A microphone is also housed within the main body and is connected to the RF module PCB. The antenna further comprises a guide piece having first and second ends, wherein the first end is secured to the second end of the main body. An opening is situated on the second end of the guide piece. An antenna is housed within the guide piece and connected to the RF module PCB. Additionally, a speaker is connected to the first end of the main body. 
   According to one aspect of the present invention, the antenna further comprises a support structure that rests against a user&#39;s face to maintain a certain distance between the guide piece and the user&#39;s face when the headset is worn by the user. The speaker is sized to fit the human ear. 
   According to one aspect of the invention, the guide piece may be hollow and cylindrical in shape configured to house the antenna. Also, the guide piece may be elongated or telescopic in construction so that the opening may be extended to the user&#39;s mouth when the headset is worn by the user. The guide piece may be connected to the RF module PCB to form a power feed. Finally, the guide piece may be made of flexible material or a portion of the guide piece may be corrugated to conform to moving in multiple directions. 
   According to another aspect of the present invention, the antenna may have a monolithic construction and may be of a monopole-type. Also, the antenna may comprise a first antenna, which is at least partially cylindrical in shape and mounted on the RF module PCB, and one or more second antenna parts, which are at least partially cylindrical in shape and connected to the first antenna part by a coaxial cable. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. 
       FIG. 1  is a perspective view of an antenna installed in an RF module; 
       FIG. 2  is a perspective view of another embodiment of an antenna installed in an RF module; 
       FIG. 3  is a perspective view of a wireless headset for a mobile communication terminal with an antenna installed therein, in accordance with one embodiment of the invention; 
       FIG. 4  is a partial cross-sectional view of the wireless headset of  FIG. 3 ; 
       FIG. 5  is a cross-sectional view of an antenna installation structure in accordance with an embodiment of the invention; 
       FIG. 6  is an enlarged cross-sectional view of circled portion ‘A’ of  FIG. 4 , showing the antenna installation structure in accordance with an embodiment of the invention; 
       FIG. 7  is a perspective view of an antenna in accordance with another embodiment of the invention; 
       FIGS. 8-12  are perspective views of the antenna in accordance with one or more embodiments of the invention. 
   

   Features, elements, and aspects of the invention that are referenced by the same numerals in different figures represent the same, equivalent, or similar features, elements, or aspects in accordance with one or more embodiments. Reference will now be made in detail to one or more embodiments of the invention, examples of which are illustrated in the accompanying drawings. 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIGS. 3-4 , a radio earphone-microphone headset in accordance with one embodiment of the present invention comprises a main body  4  having an RF module printed circuit board (PCB)  2 ; a speaker  6  installed at one end of the main body  4 ; a microphone  8  installed at the other end of the main body  4  enclosed in a support  14 ; a guide pipe  10  downwardly extended from the support  14  for guiding sound to the microphone  8 ; and an antenna  12  installed inside the guide pipe  10  and connected to the PCB  2 . 
   The main body  4  includes sufficient space for mounting the RF module PCB  2  therein. The speaker  6  is sized so as to fit in the human ear. A support  14  houses microphone  8  and is designed to rest against human face so as to provide a distance between the face and the headset when worn. 
   The guide pipe  10  is preferably cylindrical in shape and is hollow so as to serve as a passage to transmit the voice of a user to the microphone  8 . The guide pipe  10  is sufficiently long to extend within the proximity of the user&#39;s mouth when the headset is worn by the user. In one embodiment, the guide pipe  10  has a telescopic construction and can be extended to a desired position, so that opening  16  located at the terminal portion of guide pipe  10  can be positioned with the proximity of the user&#39;s mouth. 
   Referring to  FIGS. 5 and 6 , the antenna  12  is preferably cylindrical in shape for insertion into the hollow space provided in the guide pipe  10 . One end of the guide pipe  10  is mounted on the RF module PCB  2  to form a power feed  18 . The power feed point  18  is positioned close to the microphone  8 , so that antenna  12  can be easily installed by being directly mounted on the RF module PCB  2 . 
   The dimensions of the antenna  12  are configured to minimize interference with a voice signal passing the guide pipe  10 . Antenna  12  is monolithic in accordance with one or more embodiments of the invention and is preferably of a monopole type. Maximum current distribution for the antenna  12  is at the power feed point  18 . Current distribution diminishes toward the terminal point of the antenna as the current flows further away from power feed point  18 . 
   Referring to  FIG. 7 , an antenna  22  in accordance with a second embodiment of the invention has a partially cylindrical shape. Antenna  22  may be fully or partially inserted into the hollow portion of the guide pipe  10  in a manner that it would not interfere with flow of voice signals passing through guide pipe  10  as much as possible. 
   Referring to  FIG. 8 , an antenna  24  in accordance with another embodiment of the present invention is inserted into an adjustable guide  10 , so that when the guide pipe  10  is bent, the antenna can also change shape accordingly. Namely, a corrugated portion  26  is provided at a portion of the antenna  24  so that when the guide pipe  10  is bent from side to side the antenna can change shape accordingly. 
   Referring to  FIG. 9 , an antenna  30 , in accordance with another embodiment of the invention comprises: a first antenna member  34  in preferably a cylindrical form mounted on the RF module PCB  2 , and a second antenna member  36  in preferably cylindrical form connected to the first antenna member  34  by, for example, a coaxial cable  32 . A power feed is provided between the first antenna member  34  and the second antenna member  36 . Antenna  30 , in accordance with one embodiment, is a monopole-type antenna divided into two parts. The monopole-type antenna  30  has same radiation characteristics and gain of a dipole-type antenna, but has a simpler power feed method than that of the dipole type antenna. 
   Current distribution of the antenna  30  is such that the current is maximized at a portion where the first antenna member  34  and the second antenna member  36  are connected. Current distribution diminishes toward the distal ends of the first and second antenna members  34  and  36 . In certain embodiments, the monopole-type antenna  30  may be divided into more than two parts, that are connected by the coaxial cable  32 . 
   Referring to  FIG. 10 , an antenna  40 , in accordance with another embodiment of the present invention comprises: a partially cylindrical first antenna member  42  mounted on the RF module PCB, and a second partially cylindrical antenna member  44  connected to the first antenna member  42  by a coaxial cable  46 . 
   Referring to  FIG. 11 , an antenna  50  in accordance with another embodiment of the invention comprises: a hollow cylindrical antenna member  52  mounted on the RF module PCB, and an elongated second cylindrical antenna member  54  connected to the first antenna member  52  by a coaxial cable  56 . In some embodiments, antenna member  54  has a smaller diameter than the antenna member  52 . A power feed is provided between the first antenna member  52  and the second antenna member  54 . 
   Referring to  FIG. 12 , an antenna  60  in accordance to another embodiment of the invention may be divided into more than two sections connected by a coaxial cable  64 . A first section has a corrugated portion  62 , as shown. In accordance with one aspect of the invention, an end portion of the antenna is mounted on the RF module PCB for a power feed. 
   As such, an antenna for a wireless communication device, in accordance with one or more embodiments, is provided. The reception and transmission efficiency of the antenna is improved due to the provided design. 
   Although particular embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the appended claims are to encompass within their scope all changes, modifications and equivalents that fall within the true scope of the invention.