Kumar Deepak, Mondal Saikat, Deng Yiming, Chahal Premjeet
Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824, USA.
Micromachines (Basel). 2020 Nov 27;11(12):1043. doi: 10.3390/mi11121043.
In this paper, an efficient passive wireless harmonic communication system is proposed for the real-time monitoring of the pressurized pipelines. A pressure sensor is fabricated using the additive manufacturing technique and a harmonic radio frequency (RF) tag is designed to operate at the fundamental frequency () of 2 GHz that shifts the phase of the back reflected RF signal according to the applied pressure ranging from 0 to 20 psi. A power efficient phase modulation with virtually no losses is achieved using a hybrid coupler-based phase shifter that efficiently reflect back the incoming signal using an end coupled reactive impedance element/sensor. The phase delay introduced by the reactive element gets doubled with the second harmonic communication, which increases the sensitivity by a factor of two. The concept of harmonic backscattering is exploited to reduce the effects of multi-path interference and self jamming, as well as improving the signal-to-noise ratio (SNR).
本文提出了一种用于实时监测压力管道的高效无源无线谐波通信系统。采用增材制造技术制造压力传感器，并设计了一种谐波射频（RF）标签，使其在2 GHz的基频下工作，该标签根据0至20 psi的施加压力改变背向反射RF信号的相位。使用基于混合耦合器的移相器实现了几乎无损耗的高效功率相位调制，该移相器使用端耦合电抗阻抗元件/传感器有效地将入射信号反射回去。电抗元件引入的相位延迟在二次谐波通信时加倍，从而使灵敏度提高了两倍。利用谐波反向散射的概念来减少多径干扰和自干扰的影响，并提高信噪比（SNR）。
