Design Of The 433MHz RF Bidirectioal Amplifier

With the rapid development of mobile communication technology,the requirements of mankind for communication is also growing in the direction of diversifying and developing broadband.Nowadays,wireless local area network has infiltrated all aspects of life,but in many cases,for a specific application,a dedicated wireless network may need to be set up to provide higher quality mobile communication services.Taking into account the existing radio frequency circuit board most of the output power is low,and rarely have the ability to bidirectional transmission and reception,in order to improve a higher quality communication links and a broader network coverage,this paper designed a 433MHz bidirectional amplifier,by increasing the output device Power or bridge to increase the propagation distance.At the same time,433MHz belongs to the ISM(Industrial,Scientific,Medical)frequency band and has been widely used in the field of wireless communications such as walkie-talkies,wireless access control systems and parking control to provide people with conveniences in life.Therefore,the design of 433MHz bidirectional amplifier has a strong practical significance.The main work of this thesis can be summarized as follows:(1)An ATF54143 transistor from Avago Company was used to design a single-stage,low-noise amplifier that stabilizes the transistor by introducing feedback between the drain and the source,ultimately achieving high Gain and low noise.Then,a lumped element coupler is introduced on the basis of a single stage to design a balanced low-noise amplifier in this band.(2)Design a two-stage power amplifier,which driver stage using NXP's MMZ09312B amplifier chip design,the driver amplifier designed with this chip can achieve the gain of 30dB and the output power of 27dBm.After the level of AFT9MS007NT1 transistor design output power up to 5W power amplifier.(3)The power divider,detector circuit,compare circuit and transceiving control circuit are designed and combine them with single-stage low-noise amplifier and driver stage amplifier to finally achieve the design of bidirectional amplifier.In this thesis,ADS2011 software is used to complete the low noise amplifier and power amplifier simulation,design of a successful power divider with HFSS,finally Altium Designer software is used to complete the design of the circuit board then the real processing.Processing test results show that the bidirectional amplifier performance is good.In the transmission chain,the input return loss of more than 10dB,19dB gain can be achieved;in the receive chain,the input return loss up to 14dB,and to achieve 14dB gain.