微小型多频点Ka测控应答机的设计与实现

发布时间：2018-10-08 14:08

【摘要】：微小卫星研发周期短、成本低,是卫星发展的新趋势。经济的快速增长对微小卫星提出了多任务化、功能灵活性高的要求。多频点的配置是解决多任务的首要选择。我国成功发射的小卫星大多工作于S/X频段,不适合深空领域的探索,且在有限的频段资源下,高频段测控应答机的研究有重要意义。本文在研究现有应答机设计方案的基础上,提出S-Ka拓扑型测控应答机设计方案,基于超外差原理和多步变频法分别设计并实现接收链路和发射链路。接收链路为二级下变频结构,发射链路为三级上变频结构。首先,在确定链路结构方案的基础上,完成器件选型和参数匹配,并对链路增益进行预算。接收链路可实现60dBm的动态范围;发射链路输出功率在10dBm以上,功率不足可由软件补偿。其次,通过遥控和程控方式实现频率软件可调节。配置过程中,保持基带板锁相环频点不变,改变前端PLL配置字实现2GHz频带范围内的频率改变,步进是1MHz。因锁相环频率分辨率带来的频偏以软件方式补偿。然后,实现应答机软件闭环功率控制。在环境温度改变时,保证输出功率不波动。最后,继承原有X测控应答机的基带算法并加以改进,实现数字域载波跟踪环。并实现软件设计的多频率配置和闭环功率控制。实验室环境硬件链路测试结果表明,本课题设计的Ka测控应答机,实现了预期指标需求。接收信号在29GHz~31GHz范围内以1MHz步进可调;发射信号在19GHz~21GHz范围内以1MHz步进可调。收发信号相互间不存在干扰接收信号动态范围60dB。19GHz、20GHz、20.999GHz三个发射频点的整机测试结果表明,发射信号在100MHz带宽内的最大杂散为-50dBm,相位噪声均优于-85dBc@10kH,输出功率保持在10dBm以上。应答机总功耗小于12W,满足性能指标。
[Abstract]:Small satellite research and development cycle is short, low cost, is a new trend of satellite development. The rapid economic growth has put forward the requirement of multitasking and high functional flexibility for microsatellites. The configuration of multi-frequency points is the first choice to solve multi-task. Most of the small satellites successfully launched in China work in the S / X band, which is not suitable for the exploration of the deep space field, and the research of the high frequency range TT & C transponder is of great significance under the limited frequency band resources. Based on the research of the existing transponder design scheme, this paper presents a design scheme of S-Ka topology measurement and control transponder. Based on the principle of superheterodyne and the method of multi-step frequency conversion, the receiving link and transmitting link are designed and implemented respectively. The receiving link is a two-stage downconversion structure, and the transmission link is a three-stage up-conversion structure. Firstly, on the basis of determining the link structure, the device selection and parameter matching are completed, and the link gain is estimated. The receiving link can realize the dynamic range of 60dBm, and the output power of the transmission link is above 10dBm, and the insufficient power can be compensated by software. Secondly, the frequency software can be adjusted by remote control and program control. In the process of configuration, the frequency points of the baseband PLL are kept unchanged, and the front-end PLL configuration word is changed to realize the frequency change in the range of 2GHz frequency band. The step is 1MHz. The frequency offset caused by the frequency resolution of PLL is compensated by software. Then, the closed-loop power control of transponder software is realized. Ensure that the output power does not fluctuate when the ambient temperature changes. Finally, the base band algorithm of X measurement and control transponder is inherited and improved to realize the digital domain carrier tracking loop. The multi-frequency configuration and closed-loop power control of the software are realized. The results of the hardware link test in the laboratory environment show that the Ka measurement and control transponder designed in this paper has achieved the expected requirements. The received signal is stepwise adjustable by 1MHz in the range of 29GHz~31GHz and the transmitted signal is stepwise adjustable by 1MHz in the range of 19GHz~21GHz. There is no interference between the received and received signals. The test results show that the maximum spurious of the transmitted signal in the 100MHz bandwidth is -50dBm, the phase noise is better than -85dBcr 10kH, and the output power is kept above 10dBm, the dynamic range of the received signal is 60dB.19GHz 20GHz and 20.999GHz. The results show that the maximum spurious of the transmitted signal in the 100MHz bandwidth is -50dBm, the phase noise is better than -85dBcr 10kH. The total power consumption of transponder is less than 12 W, which meets the performance index.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN927.2

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