Design Of L-Band Signal Generator Integrated 500-watt High-power Circuit

Frequency generator is an important part in wireless communication, its capability will directly affect the performance of communications equipment. Meanwhile, a test circuit which can produce 500 watts of high-power and high-heat is needed to test airborne frequency generator performance. To detect whether the equipment will work in heat radiation and electromagnetic radiation, the airborne frequency generator has to be put next to the 500-watt high-power test circuit, and verificate the feasibility of the design of airborne frequency generator.In this paper, the various frequency synthesis method and signal integrity are summarized firstly, then elaborate the impedance matching technology based on the width of the signal return path and transient analysis method of unequal length lossy multiconductor transmission lines based on FDTD method. Subsequently, introduce the basic principles of the Direct Digital Synthesis (DDS) and the Phase-Locked Loop (PLL). Then, the design method of L-Band frequency generator by DDS incentives PLL and integrated 500-watt high-power circuit are given. Based on the above work, according to the system requirements, complete the schematic design. Meanwhile, by use the proposed methods to analysis the signal integrity of the system. By optimize the circuit layout and routing, the L-Band signal generator and the 500-watt high-power circuits are integrated in one printed circuit board. Finally, by using the microcontroller AT89S52, complete software debugging of the chip control code transmise, frequency output adjustable and temperature real-time detection.After repeated testing, realized the L-Band singanl frequency output and 500-watt power adjustable, and successfully integrated them in one printed circuit board, complete feasibility verification of airborn L-Band signal generator. Eventually, the project passed the acceptance.