Abstract:
An isolation device includes an upper portion, a lower portion, and an isolation area. At least one of the upper and lower portions is constructed with a flexible shielding material. The isolation device may also include a conduit having one opening in the isolation area and another opening outside the isolation area.

Description:
BACKGROUND  
       [0001]     Isolation devices are used in a variety of applications, including product and quality testing of various electronic devices. The isolation devices shield the electronic devices from interference during the testing process, which allows the test procedure to more accurately reflect device operations.  FIG. 1  is a perspective view of an isolation device according to the prior art. Isolation device  100  includes base  102 , lid  104 , and isolation area  106 . Clasps  108 ,  110  attached lid  104  to base  102  when lid  104  is in the closed position.  
         [0002]     Isolation device  100  is typically made of a rigid metallic material. The rigidity of the metallic material can limit the size and shape of the isolation device  100 . Also, depending on the type of metallic material, its thickness, and the dimensions of isolation device  100 , isolation device  100  can be expensive to manufacture and heavy and cumbersome to use.  
       SUMMARY  
       [0003]     In accordance with the invention, an isolation device includes an upper portion, a lower portion, and an isolation area. At least one of the upper and lower portions is constructed with a flexible shielding material. The isolation device may also include a conduit having one opening in the isolation area and another opening outside the isolation area.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0004]     The invention will best be understood by reference to the following detailed description of embodiments in accordance with the invention when read in conjunction with the accompanying drawings, wherein:  
         [0005]      FIG. 1  is a perspective view of an isolation device according to the prior art;  
         [0006]      FIG. 2  is a perspective view of an isolation device with a lid in an open position in an embodiment in accordance with the invention;  
         [0007]      FIG. 3  is a perspective view of the isolation device of  FIG. 2  with a lid in a closed position;  
         [0008]      FIG. 4  is a side view of the isolation device of  FIG. 2 ;  
         [0009]      FIG. 5  is a cross-sectional view of a clasp used in the isolation device of  FIG. 2 ; and  
         [0010]      FIG. 6  is a plot of RF energy versus frequency for a lid in an open position and a lid in a closed position for the isolation device of  FIG. 2 .  
     
    
     DETAILED DESCRIPTION  
       [0011]     The invention relates to a flexible isolation device that shields EMI sensitive devices from outside interference. The following description is presented to enable one skilled in the art to make and use the invention, and is provided in the context of a patent application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the generic principles herein may be applied to other embodiments. Thus, the invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the appended claims and with the principles and features described herein.  
         [0012]     With reference now to the figures and in particular with reference to  FIG. 2 , there is shown a perspective view of an isolation device with a lid in an open position in an embodiment in accordance with the invention. Isolation device  200  includes base  202 , lid  204 , and isolation area  206 . Device  208  is placed inside isolation area  206  for shielding from outside interference, such as radio frequency (RF) interference and e-field interference. In this embodiment in accordance with the invention, device  208  is implemented as a cellular telephone that employs interference shielding during device testing. In other embodiments in accordance with the invention, device  208  may be implemented as any device requiring shielding from outside interference for any purpose. For example, device  208  may be implemented as a personal digital assistant (PDA) or a notebook computer.  
         [0013]     A flexible shielding material, such as a metallic fabric, is used to construct isolation device  200  in this embodiment in accordance with the invention. One example of a flexible metallic fabric is a pre-fabricated nickel/copper fabric known as FlecTron®, manufactured by the Monsanto Company. In other embodiments in accordance with the invention, isolation device  200  may be assembled with other flexible shielding materials.  
         [0014]     The flexible shielding material allows isolation device  200  to be constructed in any desired configuration. In the  FIG. 2  embodiment, isolation device  200  is constructed in a rectangular-like shape. In other embodiments in accordance with the invention, isolation device  200  may be constructed in any desired shape. Additionally, only base  202  may be constructed with a flexible shielding material and lid  204  with a non-flexible shielding material in other embodiments in accordance with the invention. Alternatively, in yet other embodiments in accordance with the invention, lid  204  may be constructed with a flexible shielding material and base  202  with a non-flexible shielding material.  
         [0015]      FIG. 3  is a perspective view of the isolation device of  FIG. 2  with a lid in a closed position. A clasp  300  attaches lid  204  to base  202 . Cable corridor  302  is a conduit that allows device  208  (see  FIG. 2 ) to be connected to another device (not shown). For example, device  208  may be connected to a testing station by inserting a cable for the testing station into cable corridor  302 . The cable passes through cable corridor  302  to connect to device  208  in isolation area  206 .  
         [0016]     Cable corridor  302  is constructed with the flexible shielding material in this embodiment in accordance with the invention. In other embodiments in accordance with the invention, cable corridor  302  may be implemented with non-flexible shielding materials. The dimensions of cable corridor  302  are determined by each application. In the embodiment of  FIG. 3 , the length of corridor  302  is determined by the waveguide beyond cutoff frequency. The waveguide beyond cutoff frequency causes frequencies less than the cutoff frequency to be attenuated such that the frequencies are not disruptive to device  208  in isolation area  206 .  
         [0017]     Referring now to  FIG. 4 , there is shown a side view of the isolation device of  FIG. 2 . A cable  400  is inserted into cable corridor  302  to connect with a device in the isolation area (not shown). Shielding material surrounds the device when lid  204  is closed and attached to base  202 . In this embodiment in accordance with the invention, base  202 , lid  204 , and cable corridor  302  are formed using a single piece of shielding material. Other embodiments in accordance with the invention may construct shielding device  200  differently.  
         [0018]      FIG. 5  is a cross-sectional view of a clasp used in the shielding device of  FIG. 2 . Clasp  300  includes two magnetic components  502 ,  504 . Magnetic components  502 ,  504  are implemented as flexible magnetic strips in this embodiment in accordance with the invention. Magnetic components  502 ,  504  are placed around the perimeter of the isolation area (not shown). The shielding material of base  202  and lid  204  folds around magnetic components  504  and  502 , respectively. A galvanic connection is created between base  202  and lid  204  when magnetic components  502 ,  504  are aligned to attract each other. In other embodiments in accordance with the invention, different types of clasps or mechanisms that seal lid  204  to base  202  may be used.  
         [0019]     Referring now to  FIG. 6 , there is shown a plot of RF energy versus frequency for a lid in an open position and a lid in a closed position for the shielding device of  FIG. 2 . Plot  600  illustrates the amount of outside interference measured between 800 MHz and 1 GHz frequency when lid  204  is in an open position. As is shown in  FIG. 6 , the amount of interference is relatively high and the plot includes considerable variations in the level of interference. Outside interference negatively impacts devices during certain operations and product testing.  
         [0020]     Plot  602  depicts an amount of outside interference present when lid  204  is in a closed position. As can be seen, the level of interference is reduced and remains relatively constant during the frequency range of 800 MHz to 1 GHz.