Design And Realization Of GSM Double-Network Bidirectional Power Amplifier

GSM double-network bidirectional power amplifier is using in the electronic fencepositioning system which is expanding the coverage of base station electronic fence. Thesystem can be deployed in city or other sensitive areas. The system collects the G networkmobile phone users'feature information to the management center. To use the informationcollision of time and number to find out the suspects. It is necessary to consider merging thetwo networks when the police using GSM network technical investigation.There are three complete machine designs for the GSM double-network bidirectionalpower amplifier. To make sure the two-way (double net) signals can be launched at the sametime and reduce the intermodulation between signals for transmitting and receiving. Toimprove the degree of suppression between the sending and receiving signals, enhance thesensitivity of the receiver signal and achieve high power emission. At the end, we choose themost excellent performance scheme of the orthogonal power combining. This paper focuseson the design of low noise amplifier for uplink signal amplification and high power amplifierfor downlink signal amplification. Using the Agilent's ADS (Advanced Design System 2008)simulation software to simulation the DC operating point, DC bias circuit, stability of thecircuit, input / output matching circuit and the second power splitter circuit for low noiseamplifier. And also simulate the input / output matching circuit and microstrip coupling circuitfor power amplifier. To use an improved temperature compensation circuit in the design of thepower amplifier bias circuit which makes the amplifier get an accurate compensation atquiescent operating point and improves the index of the amplifier. To use AD8314 as thedetector chip in power detection circuit of the power amplifier. compared with the discretediode detector. It can provide a wider dynamic range, higher conversion accuracy and give anaccurately output value. According to the machine design, we developed the product of low-noise amplifier andpower amplifier, and testing after machine connected, the test index meets the userrequirements.