Integrated Active Antenna Arrays for Millimeter Wave Wireless Communications

9979282Pozar虽然迄今为止部署的绝大多数商业无线系统的特点是使用低于2 GHz的频率和使用低增益天线，但未来许多拟议的高速无线数据网络将使用毫米波频率和高增益天线。例如，运行在23 GHz和38 GHz的点对点无线电(主要用于蜂窝和PCS基站回程业务)、运行在28 GHz的本地多点分配系统(LMDS)，以及运行在20 GHz和30 GHz的Celestri和Teledesic低地球轨道(LEO)卫星系统的地面终端。虽然微带天线技术在过去的15年里已经相当成熟，但一个长期存在的问题是，微带馈线损耗随着天线尺寸和频率呈指数增长，因此不可能使用共面微带馈电网络来构建毫米波高增益的高效微带阵列。这里描述的研究计划建议通过研究尽可能多的关键天线和前端微波电子设备的集成来解决这一问题以及与毫米波无线系统相关的基本问题。我们将利用硅加工、晶片键合和聚合物薄膜方面的最新进展来创造几年前还不可能实现的结构。此外，通过将天线和射频电子学作为一个整体来考虑，我们将能够通过专注于处理高效率阵列所需的组件特性来大大降低成本。建议进行为期三年的研究工作，为未来的无线数据网络和系统开展毫米波天线和射频前端电路的实验和理论研究。我们将研究单一的和半混合的方法。这项研究的一个组成部分涉及开发具有特定几何、配置和特性的HBT功率放大器，该功率放大器将有利于与GaAs衬底上的微带天线元件进行单片集成，以最大限度地减少毫米波频率的馈电损耗。利用最先进的MOCVD技术，我们将在不需要纳米制造技术的情况下，在毫米波范围内开发出具有足够增益的最佳HBT结构。在HBT的制造中，我们将与雷神先进设备中心的研究人员合作，该中心目前正在开发最先进的毫米波设备和集成电路。我们将与雷神公司的研究人员就器件设计(包括外延结构和布局)、工艺序列和具体工艺步骤进行合作。我们相信，他们的经验和专业知识将极大地加强和加快我们在该项目中的HBT技术开发。参与的研究生也将从与我们的行业合作伙伴的互动中受益匪浅。*

9979282PozarWhile the vast majority of commercial wireless systems deployed to date are characterized by the use of frequencies below 2 GHz and the use of low-gain antennas, many of the proposed high-speed wireless data networks of the future will use millimeter wave frequencies and high gain antennas. Examples include point-to-point radios operating at 23 and 38 GHz (largely used for cellular and PCS base station backhaul traffic), local multi-point distribution systems (LMDS) operating at 28 GHz, and ground terminals operating at 20 and 30 GHz for the Celestri and Teledesic low-earth orbit (LEO) satellite systems. Although micro-strip antenna technology has matured considerably over the last 15 years, a persistent problem has been the fact that micro-strip feed line losses increase exponentially with antenna size and with frequency, so that it is impossible to construct an efficient high-gain micro-strip array at millimeter wave frequencies using a coplanar micro-strip feed network. The research plan described here proposes to address this and related fundamental problems associated with millimeter wave wireless systems by studying the integration of as much of the critical antenna and front-end microwave electronics as possible. We will make use of recent advances in silicon machining, wafer bonding and polymer films to create structures that were not possible just a few years ago. In addition, by considering the antenna and RF electronics as a whole unit, we will be able to greatly reduce cost by focusing on processing only the component characteristics that are necessary for high efficiency arrays.A three-year research effort is proposed to carry out experimental and theoretical investigations of millimeter wave antennas and RF front-end circuitry for future wireless data networks and systems. Both monolithic and semi-hybrid approaches will be studied. One component of the research involves the development of HBT power amplifiers with specific geometry, configuration, and characteristics that will be favorable for monolithic integration with micro-strip antenna elements on GaAs substrates to minimize feed losses at millimeter wave frequencies. Using state-of-the-art MOCVD techniques, we will develop optimum HBT structures with sufficient gain in the millimeter wave regime without the requirement of nano-fabrication technology. In fabrication of the HBTs, we will collaborate with researchers at the Raytheon Advanced Device Center where state-of-the-art millimeter wave devices and integrated circuits are presently being developed. We will work with Raytheon researchers on the device design (both epitaxial structure and layout), process sequences, and specific process steps. We believe their experience and expertise will significantly enhance and accelerate our development of HBT technology for this program. Graduate students involved will also benefit greatly from this interaction with our industrial partners.***