[Elecraft] Art of Electronics

[Jim Brown]

On 4/8/2018 11:45 AM, Kevin Cozens wrote:
> As the frequency goes up it RF design becomes part science and part 
> art, or some might say black magic.

A better way of thinking about it is that as frequency goes up, stray 
(parasitic) elements of components become increasingly significant (that 
is, L and C in a resistor, R and L in a capacitor, R and C in an 
inductor), wiring (including traces on a single layer circuit board) 
first become inductors, then antennas, and their capacitance to other 
circuit elements and their inductive coupling to other wiring becomes 
significant, and traces above a "ground layer" on a circuit board become 
transmission lines. And the TIME it takes for signals to move along 
wires and lines becomes significant. The dielectric properties of 
circuit board become significant. The spacing between circuit traces 
becomes significant.

In other words, all of the things that can often be ignored at lower 
frequencies must be considered at higher frequencies. That's not "art," 
it's not "black magic," its pure science.

73, Jim K9YC