
Technical Notes 
Characteristic Impedance
The Characteristic Impedance of a coaxial transmission line is a function
of the ratio of the inner and outer conductor diameters and the dielectric
constant of the insulating medium.


Voltage Standing Wave Ratio (VSWR)
VSWR is the ratio of the maximum and adjacent minimum wave, expressed
in terms of reflection coefficient.

VWSR is a real number; a value 1.0 implies a perfectly matched load. 
Insertion Loss
The composite Insertion Loss of a transmission line is determined by
the loss associated with the inner and outer conductor, the dielectric medium
and characteristic impedance mismatches.
1. Conductor Loss is a function of transmission line dimensions and
materials.
Where:  CL   Conductor Loss (dB)  L   Conductor length (inches) 
 Characteristic Impedance (Ohms)   Dielectric constant  
D   Inside diameter of the outer conductor (inches)   Dielectric constant  
O   Diameter of the inner conductor (inches)  f   Frequency (Hz) 
2. Dielectric Losses

3. Mismatch Loss is a function of reflected energy due to deviations from the characteristic impedance of the transmission line system