一种载波对消提高相位调制度的新技术

Novel Technique for Enhancing Modulation Depth through Carrier Cancellation

用连续波雷达测量运动目标或振动目标经常会遇到调相波的解调问题。对于无外向辐射的封闭系统,结合微波马赫-曾德尔干涉仪和灵敏高效的相位调制器,设计了一种简洁有效的技术架构,实现了载波对消。高效相位调制器提高了对振动的响应,干涉仪不但可以有效压制载波,而且极大压制了微波源的相位噪声,包括难以处理的1/f噪声。该技术适用于各种频段,可有效延伸到射频,用集中参数系统处理,这样,更加有利于调相传感器的优化和电路实现。文中给出了高效相位调制器和干涉仪系统的原理分析,验证方案和同轴系统的实验结果。该原理也适用于微带电路和集成化电路。

The demodulation of phase modulated(PM)waves is often encountered when CW radar is used to detect weak vibrating or moving objects.For closed system without outwards radiation,a compact and efficient technical architecture is designed by combining a microwave Mach-Zehnder interferometer with a sensitive phase modulator,which forms a carrier cancellation system.The sensitive phase modulator enhances the response to vibrations,while the interferometer not only cancels the carrier wave,but also reduces the phase noise of the microwave source itself even 1/f noise which is hard to deal with.This technology is suitable for different frequency bands from microwave to radio frequency where the system may be handled as lumped circuits.It will be beneficial to system optimization and realization.The principle analysis of the efficient phase modulator,the interferometer systems,verifying scheme and the demonstration of a coaxial system are presented in this paper.The basic principle is available for microstrip circuit and integrated circuit as well.