340MHz Wireless Video Transmission System RF Module Design

With the development of digital technology and the popularity of the network, Videotransmission gradually evolved from the traditional single-cable video transmission mode tothe coexistence of wired video transmission with wireless video transmission. Traditionalwired video transmission mainly applied in residential security, building monitoring, factoryproduction line monitoring and so on. In many cases, the wired video transmission isextremely inconvenient, so wireless video transmission become inevitable. In order to meet theemergency command department, department of public safety and disaster relief departmentto the needs of the frequency, Ministry of Industry and Information Technology provide the336-344MHz band frequency for dedicated mobile wireless video transmission system. As animportant part of the wireless video transmission system, the RF module plays an importantrole in promoting the development of wireless emergency communications market.Wireless communication system consists of RF parts (antenna, RF transceiver, etc). andbaseband signal processing parts (A/D conversion, digital signal processing). A RF module isdesigned in this paper, which is between antenna and the baseband signal processing, mainlyfor changing signal frequency band and amplifying signal power. The major work is asfollows:1. Getting a full understanding of the current development status of wireless videotransmission system as well as applications by a large number of data collection and reading.Compare to other wireless video transmission solution, proposing the advantages ofWiMAX-based high-speed digital wireless video transmission system.2. Researching on the IMD3, ACPR, and EVM indexes by calculation and simulation. Putforward a formula about the relationship between IMD3and output power1dB compressionpoint. Get the curve between ACPR and output power1dB compression point throughsimulation. Propose the relationship between EVM and I/Q imbalance, EVM and outputpower1dB compression point. Provide a reference for the design of the RF system.3. Proposing a340MHz band RF system solution, according to the mission statementindicators of RF module design and development requirements. Analyzing system indexes, selecting a reasonable chip solutions and completing the demonstration of the transmissionchannel and receive channel indexes with ADS.4. Completing the circuit design. Debugging and testing circuit indexes and then finallycompleting the design of the RF module.