本文翻译自Microwaves101 | Microwave Rules of Thumb，汇总了一些微波电路中的经验法则（Rules of Thumb），所谓经验法则，就是一些长期总结出来的规律，多数情况下适用，但并不是任何时候都适用，请读者自行斟酌。
The isolation of a Wilkinson is limited to 6 dB better that the return loss of the source match at its common port.Wilkinson功分器的隔离度只比公共端口的回波损耗高6dB。
The split port return loss of a Wilkinson is no better than the return loss that is seen by the Wilkinson at its common port.Wilkinson功分器功分端口的回波损耗不会比其公共端口的回波损耗更好。
An acceptable voltage droop for a power amplifier during pulsed operation is 5%, which will drop the power by a similar amount (5%, or about a quarter of a dB). So for a PHEMT amp operating at 8 volts, you allow a voltage droop of 0.4 volts. Use this rule when you calculate charge storage capacitance!功率放大器脉冲工作期间可接受的电压降落是5%，对应相当的功率降落（5%，大概0.25dB）。因此对于一个8V工作的pHEMT放大器，允许电压降落0.4V。以此计算储能电容的取值！
In order to use silicon as a substrate, you need resistivity at least 100 ohm-cm or the loss is going to eat your lunch.要想用硅当衬底材料，电阻率至少为100Ω·cm，否则损耗会大到把你饭都吃掉！
For microstrip, you can (approximately) cut metal losses in half by doubling the dielectric thickness. For example, going from 10 mil to 20 mil alumina, or two-mil to four-mil GaAs.对于微带电路，介质厚度加倍就可以令金属损耗近似减半，例如厚度10mil的铝基板改为20mil，或者2mil的GaAs改为4mil。
Any microwave semiconductor house that doesn't invest in new technology, is going to go out of business in the long run. By long run, we mean five years.任何微波半导体公司，只要不投资新技术，就一定会在五年之内死掉。
Anyone who designs complex microwave circuits and claims they don't use the optimization function in their EDA software is one of these three things: a liar, an idiot, or a super-genius with IQ 250. You pick which one, then accuse them when they bring this up at their next peer review!任何设计复杂微波电路并且宣称从来不使用EDA软件优化功能的人一定是这三种的一种：骗子、傻子、智商250以上的天才。你选一个，当下次开同业审查（同行评议）遇到这种人这样讲的时候怼他！
When laying out the top layer of a microstrip board many of us do a ground fill. The question is how close to get to the microstrip lines especially since the ground fill function is automated in many layout programs. The answer is to keep >3 line widths away. This insures minimal additional loss and impact to line impedance. Contributed by Tom!在做微波版顶层Layout的时候，很多人都会铺地，问题是应该与微带线保持多大间距，尤其是考虑到很多Layout软件都有自动铺地功能。答案是保持三倍线宽的间距，这可以确保最小的附加损耗和线路阻抗影响。
Different loss mechanisms have different behaviors over frequency. Metal loss is proportional to square-root frequency. Dielectric loss is proportion to frequency. Dielectric conduction loss is constant over frequency.不同的损耗机制随频率具有不同的表现，金属损耗与频率平方根成正比，介质损耗与频率成正比，介质传导损耗随频率保持不变。
When considering the transmission line loss due to dielectric conductivity, if the resistivity of the dielectric is greater than 10,000 Ohm-cm, forget it! That pretty much rules out all substrates except silicon, which can be anywhere from 1 Ohm-cm (very lossy) to 10,000 Ohm-cm (very expensive float-zone silicon). PTFE is 1E18 Ohm cm!考虑介质电导率导致的传输线损耗时，如果介质的电阻率高于10,000Ω·cm，直接忽略！基本上除了硅的所有衬底材料都满足，硅的电阻率从1Ω·cm（损耗很大）到10,000Ω·cm（非常昂贵的高阻硅）都可能。聚四氟乙烯的电阻率是1E18Ω·cm！
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