Physical constants

Here are some physical constants and other data in the MKS system which are useful in microwave engineering.

Sources: NIST website and the CRC Handbook of Chemistry and Physics

Constant	Description	Value	Units
k	Boltzmann's constant	1.38065030E-23	Joule/Kelvin
c	Velocity of light in free space	2.99792458E+08	meters/second
e	Base number of natural logarithms	2.71828183E+00	none
h	Planck's constant	6.62606876E-34	Joule-second
Z0	Impedance of free space	3.76730313E+02	Ohms
0	Permittivity of free space	8.85418782E-12	Farad/meter
me	Electron mass	9.10938188E-31	kilogram
N	Avagadro's constant	6.02214199E+23	mol-1
	Pi	3.14159265E+00	none
q	Electron charge	1.60217646E-19	Coulombs
0	Permeability of free space*	1.25663706E-06	Henry/meter

* exact value is 4x10-7