什么是微带线和带状线？
Stripline and microstrip are methods of routing high speed transmission lines on your PCB design. Stripline is a transmission line trace surrounded by dielectric material suspended between two ground planes on internal layers of a printed board. Microstrip routing is a transmission line trace routed on an external layer of the board. Because of this, it is separated from a single ground plane by a dielectric material.
带状线和微带线是PCB设计中高速传输线的布线方法。带状线是由介电材料包围的传输线，介于PCB内层两个接地平面之间。微带线是一种分布于电路板外层的传输线，基于此，微带线通过介电材料与单个接地平面分离。
With the transmission line on the surface layer of the board, microstrip routing has better signal characteristics than stripline. board fabrication is also less expensive with microstrip since the layer structure of one plane and one signal layer makes the manufacturing process simpler. Stripline can be more complex to manufacture because is requires multiple layers to support the embedded trace between two ground planes. However, the width of a controlled impedance trace in stripline is less than an impedance trace in microstrip of the same value. This is because of the second ground plane. These smaller trace widths enable greater densities, which in turn enables a more compact design. The internal layer routing of stripline also reduces EMI and provides better hazard protection.
由于传输线在板子的表层，微带线比带状线有更好的信号特性。在微带线的层结构中，一层信号一层地的结构使得制造过程更加简单，所以制造成本也更低。而带状线结构更加复杂，因为需要多层结构来支持两个接地层之间的嵌入式走线。然而，带状线中受控阻抗走线的宽度要小于微带线中相同阻抗下走线的的宽度。这是因为有第二个接地面的存在。这些更小的走线宽度可以实现更高的密度，从而实现更紧凑的设计。带状线的内层走线设计还会减少EMI并提供更好的风险防护。
Stripline and microstrip have different benefits. The decision of which is the better method should be based on the needs of the design. In a dense high speed design, a mixture of both methods on a multi-layer board is often used to accomplish the design goals.
带状线和微带线各有优势。在选择以何种方式布线时应基于实际的设计需要。在密集的高速设计中，在一个多层板中常混合使用两种走线方法来打到设计目标。
Furthermore, it is extremely important to maintain controlled impedance across the design when routing transmission lines on a high speed design. The layer of the PCB that the transmission line is routed on, the physical characteristics of the transmission line trace, and the characteristics of the dielectric all need to be calculated together in order to give the correct impedance values for the circuit. There are many different impedance calculators with different stripline and microstrip models that are available for making these calculations.
此外，在高速设计中布线传输线时，保持整个设计的受控阻抗极为重要。 传输线布线的PCB层，传输线迹线的物理特性以及电介质的特性都需要一起计算，以便为电路提供正确的阻抗值。 有许多不同的阻抗计算器具有不同的带状线和微带模型，可用于进行这些计算。
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