Printed Electronics Fabrication of Laminated Conductors for Loss Reduction in RF Circuits

印刷电子（PE）不同于传统的减法（例如，蚀刻）制造方法，而不是通过附加地沉积导电或介电（绝缘）材料来制造电路/器件的多种方法之一。这些包括传统的印刷方法，如柔版印刷，以及最近开发的技术，如气溶胶喷射印刷。PE方法制造成本较低，适用于柔性基板。它们还没有在高无线通信（RF）频率下广泛使用。原因是：射频电路通常由印刷在介质基板上的导电金属图案组成。减法制造方法适合于将导电轨道生产为单个厚（相对而言）导电层。但无论导体有多厚，所谓的电磁趋肤效应都会导致电流在导体的薄层内流动。因此，有效电阻（以及由此产生的不必要的功率损耗）大于如果电流可以在导电轨道的更大横截面上传播时的有效电阻（以及由此产生的不必要的功率损耗）。如何实现这一点实际上是在1951年显示，即，而不是一个单一的导电层，应该使用叠层导体组成的非常薄的导电层由极薄的介电材料分开，只是正确的厚度。这种叠层导体的电磁场穿透厚度可以是许多集肤深度，因此电流将流过可用导体横截面的更大部分。这导致功率损耗大大降低。但是减成法不适合制造叠层导体电路。本研究将使用计算电磁学分析来设计层压导体电路，并使用PE柔性版印刷来制造它们，以努力开始使PE制造方法可用于RF电路。一个可能的应用是由一家加拿大公司开发的世界上第一个完全集成的高级头部保护解决方案，用于安全和军事人员。

Printed electronics (PE) differs from conventional subtractive (eg. etching) fabrication methods and is insteadone of a number of methods to fabricate circuits/devices by additively depositing conducting or dielectric(insulating) material. These include traditional printing methods like flexography, and more recently developedtechniques like aerosol-jet printing. PE methods offer lower fabrication costs and are suited to flexiblesubstrates. They have not yet found widespread use at high wireless communications (RF) frequencies. Thereason is this : RF circuits are usually comprised of conducting metallic patterns printed on dielectricsubstrates. Subtractive fabrication methods are suited to produce conducting tracks as single thick (relativelyspeaking) conducting layers. But no matter how thick the conductor is, the so-called electromagnetic skin effectresults in the current flowing within a thin layer of the conductor. Thus the effective resistance (and henceunwanted power losses) is larger than it could be if the current could be made to spread over a larger crosssection of the conducting track. How this can be achieved was in fact shown in 1951, namely that instead of asingle conducting layer one should use laminated conductors comprised of very thin conducting layersseparated by extremely thin dielectric material, of just the correct thicknesses. Electromagnetic fieldpenetration of this laminated conductor can then be many skin depths thick and the currents will as a resultflow over larger portions of the available conductor cross-sections. This results in greatly decreased powerlosses. But subtractive fabrication methods are not suited to making laminated conductor circuits. This researchwill use computational electromagnetics analysis to design laminated conductor circuits, and PE flexography tofabricate them in an effort to start making PE fabrication methods available for RF circuits. One possibleapplication is by a Canadian company developing one of the world's first fully integrated advanced headprotection solutions for security and military personnel.