Study Of The X-band Frequency / Frequency Source Components

Microwave frequency conversion technology is an essential component of the launching and receiving systems of microwave integrated circuits. From microwave communications, radar, remote control, remote sensing, to reconnaissance and electronic countermeasures, as well as many microwave measurement system, it is an indispensable part. In the radar system, the X-band microwave is used for long-range tracking, guidance, mapping, and airborne attacks; In addition, the X-band microwave is also being widely applied in electronic equipments in satellite communications and military defense. As a result, the research of the X-band frequency conversion technology is of great significance.Through the research of PLL frequency source, Broadband frequency multiplier and up-converter, the thesis aims to complete the output of broadband sweeping signal with low spurs and high power flatness. The system has two input signals, both of which are DDS generated sweeping signal. One is narrow-band intermediate-frequency signals with the center frequency of 175 MHz and the bandwidth of 50 MHz, and another is the DDS signal, with the center frequency of 165.3125 MHz, and the bandwidth of 75 MHz. these two signals become S-band intermediate-frequency signals and X-band the vibration signals respectively through up-conversion and multiplication, and then are output through X-band frequency conversion. The output signal has a center frequency of 6 GHz and a bandwidth of±600MHz.The thesis first introduces the development of PLL frequency synthesizer technology, as well as the development of frequency multiplier home and abroad. And then, gives a general introduction to the basic principle, the main characteristics and analyzing methods of PLL frequency source, frequency multiplier and frequency mixer. Thirdly, in order to meet the system index, the thesis puts forward a designing plan and then starts analyzing. The system is divided into four main functional modules in this thesis– the PLL frequency source module that provides the DDS signal internally, the broadband frequency conversion module that outputs the X-band frequency the vibration signal, the S-band up-conversion module that outputs narrow-band intermediate-frequency signal, and the X-band frequency conversion module that generate output needed by the system through up-conversion. The thesis put forward the program design of various subsystems modules, and perfoms a feasibility study. Then, with the design of the program as a guide, the thesis starts a circuit design using related engineering Software with appropriate components. After a great amount of experiments, the design of prototype production system is completed. Finally, the thesis completes the laboratory tests, analyzes experimental results, and puts forward improvement suggestions.The difficulty of the study lies in achieving the output of broadband signal with low spurs and high power flatness. However, the development of the system was finally completed and the index is finally meet through the research and experiments of broadband frequency conversion technology, the meticulous frequency planning, the proper choice of devices, the rigorous analysis and feasibility studies, and the repeated experiments. Results show that the output power is greater than -15 dBm, the spurious suppression is better than 42 dBc, and the output power flatness is better than 4.4 dB.