Tunable RF devices for full duplex communication systems

在传统的通信系统中，FDD（频分双工）系统的收发信道工作在不同的频率上，TDD（时分双工）系统的收发信道工作在不同的时隙上。全双工（FD）的概念允许接收和发送信道以相同的频率同时工作。在同一频率上运行的能力将极大地有利于网络运营商在不需要额外频谱许可的情况下实现双通道容量。然而，实现全双工系统的主要挑战之一是发射功率从发射信道泄漏到接收信道，这可能会完全阻塞接收机的运行。因此，需要实现射频干扰消除电路，以减少发射和接收信道之间的泄漏到可管理的水平。这种电路由可调谐阻抗推进网络、移相器、可调谐延迟线网络和可变衰减器组成。由于干扰本质上是动态的，因此需要可调性，这就要求射频干扰抵消电路能够适应环境的变化。该提案涉及使用新技术，如相变材料（PCM）和绝缘体上硅机电微系统（SOI-MEMS），用于开发创建射频干扰电路所需的各种组件。工业合作伙伴Redline Communications是一家跨国无线通信网络设计和制造商，总部位于安大略省Markham。该项目将帮助培养射频工程和无线通信系统领域的几名研究生和博士后。

In traditional communication systems, the receive and transmit channels operate at different frequencies in Frequency Division Duplex (FDD) systems or at different time slots in Time Division Duplex (TDD) systems. The concept of Full Duplex (FD) allows the receive and transmit channels to operate at the same frequency and at the same time. The ability to operate at the same frequency would immensely benefit network operators to double channel capacity without the need for licensing of additional spectrum. However, one of the major challenges for the realization of full duplex systems is the leakage of the transmit power from the transmit channel to the receive channel, which can completely block the receiver operation. Therefore, a RF interference cancelation circuit needs to be implemented to reduce the leakage between the transmit and receiver channels to a manageable level. Such a circuit consists of a tunable impedance marching network, phase shifters, tunable delay line networks and variable attenuators. Tunability is needed since the interference is dynamic in nature, requiring the RF interference cancelation circuit to be able to adapt to environmental changes. The proposal deals with the use of novel technologies such as Phase Change Materials (PCM) and Silicon on Insulator Electro-Mechanical Micro-Systems (SOI-MEMS) for the development of the various components needed to create the RF interference circuit. The industrial partner, Redline Communications is a multinational wireless communication networks designer and manufacturer headquartered in Markham, Ontario. The project will help to train several graduate students and post-doctoral fellows in the fields of RF engineering and wireless communication systems.