Study Of Hybrid Integration Frequency Source Of 24GHz FMCW

Along with the more developed algorithm and chip devices, and gradually opened frequency band of Civilian radar in recent years, radar has been getting more and more applications in many fields, such as target recognition, flight navigation, ship and automotive anti-collision. Because of its advantages of high resolution, simple algorithm, all-weather work and small size, microwave and millimeterwave FMCW radar has received more and more attention. As the core of radar anti-collision system, FMCW frequency source has been widely studied. And the research of FMCW frequency source on miniaturization, low power consumption and high performance has important engineering significance and social value.Starting from the research of FMCW frequency source developments at home and abroad, this paper introduces the common plan of FMCW frequency source. And then this paper analyses their principle and compares their advantages and disadvantages. On this basis, according to the requirements of system indicators, this paper provides K-band FMCW frequency source programs by the design method of DDS driving PLL directly. Taking into account the low cost and miniaturization design, program selects DDS chip with the performance of low consumption and low cost. The program takes use of five harmonic of oscillator as the reference frequency of DDS, avoiding the multiplier, amplify and filter link of oscillator, and selects the PLL chip integrated VCO to replace the traditional PLL at the same time. The final test results can indicate that it can meet the basic subject index requirements. K-band FMCW frequency source can output 23.76~24GHz FMCW frequency signals, with good phase noise which is better than-70dBc/Hz@10KHz. The output signal power is 12 dBm, and its in-band flatness is less than 2dB with its spurious suppression higher than 45 dBc. The frequency source achieve the purpose of low power consumption and miniaturization, with 2.8W DC power consumption and 58×53×19mm3 circuit dimension.After the completion of the frequency source, this paper has designed transceiver front-end integrated micro-strip array antenna and down-converter based on the FMCW frequency source, and used transceiver front-end to verify the ranging function. In order to achieve the purpose of power reasonable distribution and cost down, the program selects down-converter chip with harmonic mixing function. The antenna uses transceiver double antenna, which has better isolation degree, and uses planar micro-strip array antenna with conformal cavity surface to reduce the volume of the system. Micro-strip array antenna azimuth Angle is 7 degrees, and the elevation is 28 degrees, with sidelobe suppression 16 db. It has the good direction, and its design size is 103×66×0.508mm3.Restricted by experimental conditions, this article carries on the close ranging experiment(3m, 4m, 5m, 7m, 8m, 9m).The experimental results show that this system can realize the target distance measurement, and the measurement accuracy is better.