基于相位重合检测包络特征的相位噪声测量
发布时间：2018-12-13 19:18
【摘要】：本文提出了基于相位重合检测包络特征的相位噪声(简称相噪)测量方法,这是一种全新的测量方法。它的理论基础包括：周期性信号间的相位关系、相位重合检测线路特性和维纳-辛钦定理。利用相位重合检测线路检验参考和被测信号的相位重合点时,由于线路存在一定的分辨率,所以在两信号的相位差小于一定的值时,都会输出重合脉冲。因为参考和被测信号的标称频率相同或者成倍数并带有微小偏差,所以两信号间的相位差变化存在单调性。因此,相位重合检测线路输出的重合脉冲是集中出现的,呈现出一种包络的形状。利用基于相位重合检测的频率测量实验,说明了相位重合检测包络是相对稳定的。同时,包络又存在着细微的变化,这是由相噪引起的,所以可以由包络的变化提取信号的相位抖动信息,从而测得信号的相噪。由参考和被测信号间的相位关系可知,理想的包络是三角形状的。根据采集的实际包络信息,可以推算出理想的包络状况。将采集的包络信息和理想的包络进行比较,可以得到和相位起伏相对应的电压起伏。根据理想包络的电压步进和量化相移分辨率的关系,可以从电压起伏中提取信号的相位抖动。最后,按照维纳-辛钦定理将相位抖动转化为相噪,从而作出相噪曲线。与传统的相噪测量方法相比,基于相位重合检测包络的相噪测量方法有三个特点：第一,这一方法不需要参考和被测信号的频率相同,而传统的测量方法在频率差异较大时会出现无法锁相情况,从而导致无法测量。即使可以测量,锁相过程相当复杂,花费的时间也相当的长。第二,利用重合检测包络提取相位抖动,不需要复杂、高精度的混频电路和锁相电路,线路简单,且成本较低。第三,利用维纳-辛钦定理将相位抖动转化为单边带相噪,理论基础充分。文中详细介绍了相位抖动的提取和转化为单边带相噪的过程,以及相噪测量系统的硬件和软件实现。硬件主要包括信号的整形放大、电平转换以及重合检测。软件主要是基于LabVIEW的相位抖动提取和到相噪的转换。同时,利用这一系统对频率源的相噪进行测量,并将其测量结果和PN8010的进行比较和分析,找出其中的不足,然后进行适当的改进。基于相位重合检测包络的相噪测量系统目前可以反映信号源的相噪的整体趋势,但是无法反映一些细微的特征,一些后期的调整还没有搞清楚原因,有待以后继续研究。
[Abstract]:In this paper, a phase noise measurement method based on phase coincidence detection envelope feature is proposed, which is a new measurement method. Its theoretical basis includes the phase relationship between periodic signals, phase coincidence detection circuit characteristics and Wiener-Sinchinding theorem. When the phase coincidence is used to detect the phase coincidence point of the reference signal and the measured signal, because the line has a certain resolution, when the phase difference of the two signals is less than a certain value, the coincidence pulse will be output. Because the nominal frequency of the reference and the measured signal is the same or multiple with small deviation, the phase difference between the two signals is monotonic. Therefore, the output coincident pulse of phase coincidence detection line is concentrated, showing an envelope shape. The frequency measurement experiment based on phase coincidence detection shows that the envelope of phase coincidence detection is relatively stable. At the same time, there is a slight change in the envelope, which is caused by the phase noise, so the phase jitter information of the signal can be extracted from the change of the envelope, and the phase noise of the signal can be measured. The phase relationship between the reference and the measured signal shows that the ideal envelope is triangular in shape. According to the actual envelope information collected, the ideal envelope condition can be calculated. By comparing the collected envelope information with the ideal envelope, the voltage fluctuation corresponding to the phase fluctuation can be obtained. The phase jitter of the signal can be extracted from the voltage fluctuation according to the relationship between the voltage step of the ideal envelope and the resolution of the quantized phase shift. Finally, the phase jitter is transformed into phase noise according to Wiener-Sinchin theorem, and the phase noise curve is obtained. Compared with the traditional phase noise measurement method, the phase noise measurement method based on phase coincidence detection envelope has three characteristics: first, this method does not need the same frequency of reference and measured signal. However, the traditional measurement methods can not be phase-locked when the frequency difference is large, which leads to undetectable. Even if it can be measured, the phase locking process is complex and takes a considerable amount of time. Secondly, the phase jitter is extracted by using coincidence detection envelope, which does not require complex, high-precision mixing circuit and phase-locked circuit. The circuit is simple and the cost is low. Thirdly, using Wiener-Sinchin theorem to transform phase jitter into single sideband phase noise, the theoretical basis is sufficient. In this paper, the process of phase jitter extraction and transformation into single sideband phase noise, and the hardware and software implementation of phase noise measurement system are introduced in detail. Hardware includes signal shaping and amplification, level conversion and coincidence detection. The software is mainly based on LabVIEW phase jitter extraction and phase noise conversion. At the same time, the system is used to measure the phase noise of the frequency source, and the results of the measurement are compared and analyzed with PN8010 to find out the shortcomings, and then make appropriate improvement. The phase noise measurement system based on phase coincidence detection envelope can reflect the overall trend of phase noise of signal source at present, but it can not reflect some subtle features.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM937.4
本文编号：2377078
[Abstract]:In this paper, a phase noise measurement method based on phase coincidence detection envelope feature is proposed, which is a new measurement method. Its theoretical basis includes the phase relationship between periodic signals, phase coincidence detection circuit characteristics and Wiener-Sinchinding theorem. When the phase coincidence is used to detect the phase coincidence point of the reference signal and the measured signal, because the line has a certain resolution, when the phase difference of the two signals is less than a certain value, the coincidence pulse will be output. Because the nominal frequency of the reference and the measured signal is the same or multiple with small deviation, the phase difference between the two signals is monotonic. Therefore, the output coincident pulse of phase coincidence detection line is concentrated, showing an envelope shape. The frequency measurement experiment based on phase coincidence detection shows that the envelope of phase coincidence detection is relatively stable. At the same time, there is a slight change in the envelope, which is caused by the phase noise, so the phase jitter information of the signal can be extracted from the change of the envelope, and the phase noise of the signal can be measured. The phase relationship between the reference and the measured signal shows that the ideal envelope is triangular in shape. According to the actual envelope information collected, the ideal envelope condition can be calculated. By comparing the collected envelope information with the ideal envelope, the voltage fluctuation corresponding to the phase fluctuation can be obtained. The phase jitter of the signal can be extracted from the voltage fluctuation according to the relationship between the voltage step of the ideal envelope and the resolution of the quantized phase shift. Finally, the phase jitter is transformed into phase noise according to Wiener-Sinchin theorem, and the phase noise curve is obtained. Compared with the traditional phase noise measurement method, the phase noise measurement method based on phase coincidence detection envelope has three characteristics: first, this method does not need the same frequency of reference and measured signal. However, the traditional measurement methods can not be phase-locked when the frequency difference is large, which leads to undetectable. Even if it can be measured, the phase locking process is complex and takes a considerable amount of time. Secondly, the phase jitter is extracted by using coincidence detection envelope, which does not require complex, high-precision mixing circuit and phase-locked circuit. The circuit is simple and the cost is low. Thirdly, using Wiener-Sinchin theorem to transform phase jitter into single sideband phase noise, the theoretical basis is sufficient. In this paper, the process of phase jitter extraction and transformation into single sideband phase noise, and the hardware and software implementation of phase noise measurement system are introduced in detail. Hardware includes signal shaping and amplification, level conversion and coincidence detection. The software is mainly based on LabVIEW phase jitter extraction and phase noise conversion. At the same time, the system is used to measure the phase noise of the frequency source, and the results of the measurement are compared and analyzed with PN8010 to find out the shortcomings, and then make appropriate improvement. The phase noise measurement system based on phase coincidence detection envelope can reflect the overall trend of phase noise of signal source at present, but it can not reflect some subtle features.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM937.4
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