The Design Of 433MHz And 868MHz Dual-band Wireless Communication Module

Body area networks for monitoring human physiological information emerged in recent years. It has great potential in telemedicine, community care and modern sports. So people have developed many different wireless sensors for body area networks. These wireless sensors use different communication band. They can't communicate with each other. A dual-band wireless communication module can make sensors communicate in different band. It can improve the compatibility of communication module a lot. When the Jam happened the dual-band wireless communication module can avoid the electromagnetic interference in some band and improve the reliability of wireless communication.In this paper, we first studied communication band, modulation and structure of transceiver to get the overall design. The design use 433 MHz band and 868 MHz band.ADF7020 is used as a wireless transceiver. MSP430 controls the transceiver?Then the hardware circuit of communication module is designed. The hardware circuit includes frequency synthesizer, impedance matching circuit and switching circuit. Based on the completion of the hardware the MCU programming has been designed. It used the clock system, timer interrupt and universal serial interface SPI. By using these functions,the MCU controlled the RF transceiver chip to send and receive data and to switch to different bands. The MCU communicate with transceiver chip by the specified I/O pins.At last the verification and test are completed. The test includes hardware testing, software test and transceiver function test. The test showed that the hardware circuit was right and microcontroller outputted the right clock wave and data wave. The whole communication module can switch to each band and complete the communication in 433 MHz and 868 MHz. The data rate is 10Kbps...