Abstract:
The present invention provides an automatic detecting device for radio frequency environment used to detect radio frequency noise. The device uses an antenna to receive radio frequency noise and the radio frequency noise is passing a radio frequency comparator and transformed into a voltage signal. Then, the voltage signal passes through an amplifier and is amplified to be an output voltage. If the output voltage exceeds a threshold voltage, it drives a post stage circuit to warn when the radio frequency noise is beyond a normal value.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to an automatic detecting device, and more particularly to an automatic detecting device for radio frequency noise. 
     2. Description of the Prior Art 
     While testing the element of the radio frequency circuit, the detection of manufacturing environment is required to execute. Because manufacturing environment may be affected by the radio frequency noise and the testing might fail, Pass-bin becomes Fail-bin or Fail-bin becomes Pass-bin. Therefore, before production, the ways of using the radio communication devices and the factors which can affect the testing of high frequency elements may usually be restricted. But general detection of manufacturing environment only performs limited protection, such as the indoor noise from the reflection or scattering of Auto Test Equipment (ATE). General detection of manufacturing environment is not effective to detect radio frequency noise around the element under test, and it is difficult to determine whether the radio frequency noise is excess or not, thereby affecting the result of testing the pin. In other words, the detection method of the manufacturing environment described above could reduce the jamming of radio frequency noise, but cannot detect the influence by the noise around the manufacturing environment. 
     For the reason above, it is necessary to provide a method for alerting whether the radio frequency noise is excess or not when manufacturing. During testing Load Board or designing Chip Evaluation Board (EVB), the layout for the antenna is added into the Print Circuit Board (PCB). The antenna is implemented with the testing software to detect the frequency bandwidth, which is easy to generate the noise (such as mobile phone chips) or is usually used by the customers. Since the antenna is close enough to the element under test, and the testing environment between the antenna and the element under test is similar, the antenna can almost detect the environment noise while the element is being tested. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing omission of the prior art, the present invention provides an automatic detecting device for radio frequency environment and method used to detect radio frequency noise. The detecting result of the element under test is correct while the radio frequency noise is not excess, and the detecting result of the element under test is wrong while the radio frequency noise is excess. 
     According to the object, the present invention provides an automatic detecting device for radio frequency environment to detect radio frequency noise. The antenna, especially a Planar Inverted F Antenna, is used to receive the radio frequency noise, the post stage circuit, such as a counter, a Light Emitting Diode (LED) or a buzzer, is used to warn when the radio frequency noise is beyond a normal value. The counter is used to count the numbers of times when the radio frequency noise is excess. If the detecting result indicates that the radio frequency noise is excess, the glittering of the Light Emitting Diode (LED) or the sound of the buzzer could be used to warn when the radio frequency noise is beyond a normal value. 
     According to another object, the present invention provides a method to detect radio frequency noise. First of all, an antenna is used to receive the radio frequency noise, then, a comparator is used to convert the radio frequency noise into voltage signals. After that, the voltage signals are amplified by an amplifier, and then drive the post stage circuit to warn when the radio frequency noise is beyond a normal value. 
     According to the foregoing objects, the present invention provides an automatic detecting device for radio frequency environment and method to detect radio frequency noise. The automatic detecting device for radio frequency environment receives the radio frequency noise by an antenna, converts the input radio frequency signals into voltage signals by a radio frequency comparator, and amplifies the voltage signals by an amplifier (ex, voltage amplifier). If the voltage exceeds a threshold voltage, a post stage circuit would be driven to warn when the radio frequency noise is beyond a normal value. The automatic detecting device for radio frequency environment includes an antenna to receive the radio frequency noise, a radio frequency comparator to output the voltage signal, an amplifier to drive a post stage circuit by amplifying the very low output voltage, and a post stage circuit, such as a counter, a LED warning light or a buzzer, to warn when the radio frequency noise is beyond a normal value. Furthermore, in order to receive omni radio frequency noise, a motor could be installed to make the antenna or the automatic detecting device for radio frequency environment to rotate clockwise or counterclockwise. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an automatic detecting device for radio frequency environment according to an embodiment of the present invention. 
         FIG. 2  is a view illustrating a relationship between input radio frequency signals and output voltages of the radio frequency comparator of the present invention. 
         FIG. 3  is a view illustrating a radio frequency input signals, output signals of the radio frequency comparator and output signals of the amplifier according to an embodiment of the present invention. 
         FIG. 4A  shows an automatic detecting device with a rotating antenna driven by a motor for radio frequency environment according to an embodiment of the present invention. 
         FIG. 4B  shows a rotating automatic detecting device driven by a motor for radio frequency environment according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The detailed description of the present invention will be discussed in the following embodiments, which are not intended to limit the scope of the present invention, but can be adapted for other applications. While drawings are illustrated in details, it is appreciated that the quantity of the disclosed components may be greater or less than that disclosed, except expressly restricting the amount of the components. 
     Based on the operated frequency band 900 MHZ, 1800 MHZ and 2400 MHZ, the antenna, especially Inversed F Antenna (IFA) applied in mobile phones is proper to be used for receiving noise (ex, radio frequency noise) in the present invention. There are three basic types in IFA: 1. Conventional wire element IFA, 2. Planar IFA, and 3. Integrated IFA. Regarding the planar IFA, a big plane is used to substitute the conventional transmission line, so the disadvantage of narrow bandwidth of Conventional wire element IFA is improved. Moreover, the integrated IFA is capable of wide bandwidth, but the antenna directivity character is poor. The antenna pattern of PIFA is better because it is less affected by the ground effect. In short, the PIFA is the best to receive radio frequency noise because its wide bandwidth and better radio frequency receiving character. On the contrary, the conventional wire element IFA and the integrated IFA can also be used to receive radio frequency noise in the present invention. It is not limited in this specification. 
       FIG. 1  shows an automatic detecting device for radio frequency environment according to an embodiment of the present invention. As shown in  FIG. 1 , the automatic detecting device for radio frequency environment  100  includes an antenna  102 , a comparator  104 , an amplifier  106  (ex, voltage amplifier) and a post stage circuit  108 . The antenna  102  is connected to the comparator  104 , the comparator  104  is connected to the amplifier  106 , and the amplifier  106  is connected to the post stage circuit  108 . The post stage circuit  108  includes a counter, a LED or a buzzer. The counter is used to count the numbers of times when the radio frequency noise is excess, and the Light Emitting Diode (LED) will glitters or the buzzer will sound when the radio frequency noise is beyond a normal value. After receiving noise (such as radio frequency noise) by the antenna  102 , the comparator  104  with multi-level output will process the received radio frequency noise, convert it to DC level and output. The comparator  104  is able to output different DC voltages according to the intensity of the received radio frequency signals. It is useful to detect the intensity of the radio frequency signals. Users distinguish whether the radio frequency noise is beyond a normal value by the output of the DC level. The output pins of the comparator  104  are connected to the amplifier  106  which amplifies the output voltage. When the output voltage is beyond a normal value, the amplifier  106  drives the post stage circuit  108  to warn when radio frequency noise is excess. Based on the environment condition or designer&#39;s need, the post stage circuit  108 , such as a counter, a LED or a buzzer, is able to detect the intensity of radio frequency signals and analyze it. Different post stage circuits  108  (such as a counter, a LED or a buzzer) need different drive voltages. Therefore, a resistor  110  is added in the output of the amplifier  106 , and different post stage circuit  108  can be driven by selecting the resistance of the resistor  110 . 
       FIG. 2  illustrates a relationship between input radio frequency signals and output voltages of the radio frequency comparator with multi-level output of the present invention. In  FIG. 2 , AP8313 comparator manufactured by Analog Device Inc. is used as the comparator  104 , and test data herein is also from Analog Device Inc. The comparator  104  demodulates the radio frequency signal, converts it to DC level and outputs. In other words, the function of the comparator  104  is to convert the radio frequency signal to the voltage signal. The antenna  102  for receiving radio frequency signals is connected to the input of the comparator  104 . The amplifier  106  for amplifying voltage signals to drive the post stage circuit  108  is connected to the output of the comparator  104 . As shown in  FIG. 2 , at normal temperature 25° C., the modulus of the output voltage of comparator  104  is approximately larger than 0.6 volt, but approximately smaller than 1.7 volt. While the output voltage  202  converted from radio frequency noise exceeds that range, the error  204  would be 2 or −1.5 decibel substantially. It is showing that the radio frequency noise is beyond a normal value while the modulus of output voltage  202  is higher than 1.7 volt, and the post stage circuit would be driven to warn by the amplifier  106 . Because the output voltage  202  from the comparator  104  is not large enough, it is necessary to add the amplifier  106  to drive the post stage circuit  108 . The output voltage of the comparator  104  is negative, therefore the amplifier  106  is usually an inverse amplifier to convert into positive voltage to drive the post stage circuit  108 . 
       FIG. 3  is a graph which illustrates frequency comparator and output signals of the amplifier according to  FIG. 1 . AP8313 comparator manufactured by Analog Device Inc. is used as the comparator  104 , and test data herein is also from Analog Device Inc. The radio frequency input signal  302  represents power, and decibel (dB) is its unit. As the radio frequency input increases, the output from the comparator  104  (ex, radio frequency comparator) also increases. The voltage of the output signal  304  from the comparator  104  is negative and almost steady. After being processed by the inverse amplifier  106 , an output signal  306  which is positive square wave voltage would be transmitted from the amplifier  106  to drive the post stage circuit  108 . As shown in  FIG. 3 , the radio frequency signal varies with time and environment. As the radio frequency signal is too weak, the output voltage from the amplifier  106  is not large enough to drive the post stage circuit  108 , such as a counter, a LED or a buzzer, and that means the radio frequency noise around the test environment is not beyond a normal value to make the pin test fail. On the contrary, while the radio frequency signal is large, the output voltage from the amplifier  106  would drive the post stage circuit  108  to warn when the radio frequency noise is beyond a normal value. Also shown in  FIG. 3 , the function of the comparator  104  is to convert the received radio frequency noise into a voltage signal and transmit this voltage signal to the inverse amplifier  106  to drive the post stage circuit  108 . Besides, the output voltage of the comparator  104  is negative, and is increased as the radio frequency input signal  302  increases. The output voltage of the comparator  104  is proportional to the radio frequency input signal  302 . The output signal  306  is positive because it is processed by the inverse amplifier  106 . In the embodiments shown in  FIG. 2  &amp;  3 , AP8313 comparator manufactured by Analog Device Inc. is utilized. It is noted that comparator with similar function could be used and not limited. 
       FIG. 4A  shows an automatic detecting device with a rotating antenna driven by a motor for radio frequency environment according to an embodiment of the present invention. The automatic detecting device for radio frequency environment  400  includes an antenna  402 , a comparator  404  (ex, radio frequency comparator), an amplifier  406 , a post stage circuit  408  and a motor  410 . As shown, the antenna  402  is connected to the comparator  404 , the comparator  404  is connected to the amplifier  406 , and the amplifier  406  is connected to the post stage circuit  408 . The post stage circuit  408  includes a counter, a LED or a buzzer. In order to broaden receiving range and not be limited by a single direction while the antenna  402  receives radio frequency noise, a motor  410  is installed and drives the antenna  402  to rotate, and the radio frequency noise would be detected more easily and accurately. In such way, the sensitivity and the accuracy of the present detecting device would be improved. 
       FIG. 4B  shows a rotating automatic detecting device driven by a motor for radio frequency environment according to another embodiment of the present invention. As shown, an antenna  402  is connected to a comparator  404 , the comparator  404  is connected to an amplifier  406 , and the amplifier  406  is connected to a post stage circuit  408 . The post stage circuit  408  includes a counter, a LED or a buzzer. However, the whole detecting device is mounted on a motor  410  and rotated by motor  410 . In such way, the antenna is not fixed but shifting, and the radio frequency noise would be detected more easily to reduce the pin test error. 
     Although specific embodiments have been illustrated and described, it will be appreciated by those skilled in the art that various modifications may be made without departing from the scope of the present invention, which is intended to be limited solely by the appended claims.