Patent Publication Number: US-2012034883-A1

Title: Wireless transceiver

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a wireless transceiver for a portable device. 
     2. Description of Related Art 
     Portable devices such as mobile phones, personal digital assistants (PDA) and laptop computers are widely used. Transceivers are installed in such portable devices to receive/send wireless signals. Generally, the transceivers may magnify received wireless signals with an amplifier. However, most transceivers are insensitive to the received wireless signals so that magnitude of the received wireless signals are out of a proper working range of the amplifier. Communication quality of the portable devices may be affected. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Aspects of the present disclosure can be better understood with reference to the following drawings. The components in the various drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding sections throughout the figures. 
         FIG. 1  is a block diagram of one embodiment of a wireless transceiver. 
         FIG. 2  is a measurement diagram of one embodiment of the wireless transceiver of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  a block diagram of one embodiment of a wireless transceiver  100 . The wireless transceiver  100  comprises an antenna  10 , a switch  20 , a first receiver amplifier  30 , and a transceiver module  40 . The antenna  10  connects to the switch  20 . The transceiver module  40  directly connects to the switch  20  at one end, and connects to the switch  20  via the first receiver amplifier  30  at the other. The antenna  10  transmits/receives radio signals. The switch  20  determines if the antenna  10  is in a transmission or reception mode. 
     The transceiver module  40  comprises a transmitter TX, a receiver RX, a second receiver amplifier  41 , and a signal processor  42 . The transmitter TX connects to the switch  20  forming a path for signal transmission from the transmitter TX, through the switch  20 , to the antenna  10 . The second receiver amplifier  42  connects to the first receiver amplifier  30  via the receiver RX at one end, and connects to the signal processor  42  at the other, forming a path for signal reception from the antenna  10 , through the first receiver amplifier  30 , the receiver RX, the second receiver amplifier  30 , to the signal processor  42 . 
     The signal processor  42  further connects to the first receiver amplifier  30  so that the signal processor  42  can adjust one or more working modes of the first receiver amplifier  30  and the second receiver amplifier  41 , according to a comparison of a threshold pre-set in the signal processor  42  with received radio signals (hereinafter “sensitivity”). In the embodiment, the first receiver amplifier  30  and the second receiver amplifier  41  are low noise amplifiers providing a bypass mode and a gain mode, where the bypass mode is a low-gain mode, and the gain mode is a high-gain mode. 
       FIG. 2  is a measurement diagram of one embodiment of the wireless transceiver of  FIG. 1 . When the first receiver amplifier  30  operates in the bypass mode and the second receiver amplifier  41  operates in the bypass mode, the sensitivity of the wireless transceiver  100  is in a first range. Curve S 10  and S 11  represent a maximum and a minimum value of the first range respectively. When the first receiver amplifier  30  operates in the gain mode and the second receiver amplifier  41  operates in the bypass mode, the sensitivity of the wireless transceiver  100  is in a second range. Curves S 20  and S 21  represent a maximum and a minimum value of the second range respectively. When the first receiver amplifier  30  operates in the bypass mode and the second receiver amplifier  41  operates in the gain mode, the sensitivity of the wireless transceiver  100  is in a third range. Curves S 30  and S 31  represent a maximum and a minimum value of the third range respectively. When the first receiver amplifier  30  operates in the gain mode and the second receiver amplifier  41  operates in the gain mode, the sensitivity of the wireless transceiver  100  is in a fourth range. Curve S 40  and S 41  represent a maximum and a minimum value of the fourth range respectively. 
     In the embodiment, the first range overlaps the fourth range, such that an upper boundary of the fourth range exceeds a lower boundary of the first range. A difference of the upper boundary of the fourth range and the lower boundary of the first range is no less than 10 dB. 
     It is understood that the signal processor  42  controls the sensitivity of the wireless transceiver  100  by adjusting the one or more working modes of the first receiver amplifier  30  and the second receiver amplifier  41 . For example, the signal processor  42  alters the sensitivity of the wireless transceiver  100  from the first range to the third range by switching the second receiver amplifier  41  from the bypass mode to the gain mode. In the embodiment, the threshold used to define the sensitivity of the wireless transceiver  100  is half of a sum of S 11  and S 40 . 
     The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one. 
     It is to be further understood that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of structures and functions of various embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the present invention to the full extent, indicated by the broad general meaning of the terms in which the appended claims are expressed.