### Tee Attenuator
___a___ is attenuation in dB<br>
___Z<sub>in</sub>___ is desired input impedance in &#x2126;<br>
___Z<sub>out</sub>___ is desired output impedance in &#x2126;<br>

___L = 10<sup>a/20</sup>___<br>
___A = (L+1) / (L&minus;1)___<br>
___R<sub>2</sub> = 2&middot;&radic;(L &middot; Z<sub>in</sub> &middot; Z<sub>out</sub>) / (L&minus;1)___<br>
___R<sub>1</sub> = Z<sub>in</sub> &middot; A &minus; R<sub>2</sub>___<br>
___R<sub>3</sub> = Z<sub>out</sub> &middot; A &minus; R<sub>2</sub>___