Jiang Yuzheng, Li Jing, Yan Miaoxia, Tian Cheng, Pei Li, Ning TiGang
Appl Opt. 2024 Apr 20;63(12):3334-3342. doi: 10.1364/AO.510858.
A channelized multi-frequency measurement system based on asymmetric double sideband detection is proposed. In this scheme, the sub-modulators of the dual-parallel Mach-Zehnder modulator are utilized for optical frequency comb (OFC) generation and under-test signal modulation. Subsequently, a sawtooth wave voltage is applied to the main modulator to introduce frequency shift to the modulated signals, breaking the symmetry between the RF signals and the OFC. The coupled signal is then divided into upper and lower sidebands for frequency down-conversion. By calibrating the measurement results of the two sidebands with each other, the frequency of the signal can be accurately measured. Simulation is preformed to realize multi-frequency measurement of microwave signals with measurement error less than 2 MHz in the range of 2.2-20 GHz. It is also found that the proposal can solve the problem of frequency ambiguity.
提出了一种基于非对称双边带检测的信道化多频测量系统。在该方案中，双并行马赫-曾德尔调制器的子调制器用于产生光频梳（OFC）和调制被测信号。随后，向主调制器施加锯齿波电压，以引入调制信号的频移，打破射频信号与光频梳之间的对称性。然后将耦合信号分为上下边带进行频率下变频。通过相互校准两个边带的测量结果，可以精确测量信号的频率。进行了仿真，以实现对2.2 - 20 GHz范围内微波信号的多频测量，测量误差小于2 MHz。还发现该方案可以解决频率模糊问题。
