SBIR Phase I: MHz Strip-Line Transformer for Switching Power Supplies

小行星9561627 这个小型企业创新研究（SBIR）第一阶段项目开发用于MHz和更高频率的开关电源的无芯变压器。 集成电路的小型化并没有伴随着其电源尺寸的类似减小。 虽然高频操作总是与较小的能量存储组件相关联，但较小的电力变压器受到增加的铁芯和欧姆损耗以及较高频率下的寄生效应的限制。 一个新的概念是一个Transformer没有铁氧体磁芯，并组成了一个级联的印刷带状线的多层结构。 其思想是通过电磁波通过波导结构（传输线）存储和传输能量。 这些Transformer结构的重要特征是波导波长量级的带状线长度和由带状线特性阻抗确定的匝数比。 带状线的相位常数和线阻抗作为各种参数的函数，将通过计算机辅助设计（CAD）方法来确定。 实际的设计问题将得到解决，包括最大可能的电压比与约束的设备的尺寸，可能的低损耗材料与高介电常数或磁导率的波长减少，带宽增强的方法，和带状线的几何形状的最佳使用的平面表面。 其他设计问题将包括功率处理和散热能力。 变压器在功率处理电路中是重要的，这是在所有常见的电器，手机，电视机，录像机，计算机等所需的尺寸和重量的减少和速度的提高需要新的电源转换器的开关频率在兆赫和更大的范围。 在这个范围内缺乏令人满意的电子电力变压器可能是值得商业化的。

9561627 Castaneda This Small Business Innovation Research (SBIR) Phase I project develops coreless transformers in switching power supplies for Mhz and greater frequencies. The miniaturization of integrated circuits has not been accompanied by a similar reduction in the size of their power supplies. Although high-frequency operation has always been associated with smaller energy storage components, smaller power transformers are limited by increasing core and ohmic losses and by parasitic effects at higher frequencies. A new concept is a transformer without ferrite core and consisting of a cascade of printed striplines on multilayer structures. The idea is to store and transfer energy by electromagnetic waves through waveguiding structures (transmission lines). Important features of these transformer structures are stripline lengths on the order of the guide wavelength and a turns-ratio determined by the stripline characteristic impedance. Phase constants and line impedance of the striplines, as a function of various parameters, will be determined by Computer Aided Design (CAD) methods. Practical design issues will be addressed including maximum possible voltage ratio obtainable with the constraint of the device's dimensions, possible low-loss materials with high permitivity or permeability for wavelength reduction, a bandwidth enhancement method, and the geometrical shape of the stripline for the best use of the planar surface. Other design issues will include power handling and heat dissipation capabilities. Transformers are important in power processing circuits, which are required in all common electric appliances, cellular phones, television sets, VCRs, computers, etc. Size and weight reduction and speed enhancements require new power converters with switching frequencies in the Mhz and greater range. An absence of satisfactory electronics power transformers in this range may be worthwhile commercially.