Research Of Wideband Wireless Radio Frequency Techniques

With the continuous progress of science and technology, in recent years wireless communication has a fast development. And it has been widely applied in the many fields. As a new generation of wireless LAN standards,802.11ac provides higher signal throughput, while worked with5GHz band, it can provide a wider space and more channels. It can avoid the interfere of wireless surveillance cameras and microwave ovens.The main topic of research in wireless communication system, is RF technology. This paper first introduces the basic theory of RF circuits, including microstrip filter design and simulation of scattering parameters. Then the paper focused on a research project named a design of wireless communication system based on802.11ac stabdards. The system in accordance with802.11ac physical layer index designed to support dual-band2.4GHz and5.7GHz frequency, the bandwidth of the transmitted signal is80MHz. The design includes two parts, one dual-band power amplifier module design, and second RF transceiver module design. The paper first introduce an overall dedign of wireless communication system, and then focuses on the RF part of the hardware circuit,finally integrated with baseband module and test the overall system performance.The paper give a detailed description of the design and implementation of the system hardware circuit, including the selection of the device, the LO leakage suppression, receiver AGC circuit design, image frequency suppression. And do some simulation and debugging works for SAW filters so that the flatness characteristics required to achieve targets. System performance test section introduces the RF module tone tests, including linearity characteristics such as power, gain, dynamic range and nonlinear characteristics such as1dB compression point, third-order intercept point, spirious and so on. Finally, under laboratory conditions integrated RF module and baseband module, test the system’s loopback EVM, and set up environment to build a single input single output system and test EVM value in outdoors wireless environment. Finally we got the basic system test data and it meets the design specifications.