- an introduction or tutorial to the essentials of phase locked loop, PLL frequency synthesizer operation and design. PLL frequency synthesizers are widely used in all forms of radio communications equipment today.
Twisted pair cabling is a type of wiring in which two conductors of a single circuit are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources; for instance, electromagnetic radiation from unshielded twisted pair (UTP) cables, and crosstalk between neighboring pairs.
In the straight cable, all noise current is flowing in the same direction, just like in an ordinary transformer coil. When the cable is twisted, in some parts of the signal lines the direction of the noise current is the opposite from the current in other parts of the cable. Because of this, the resulting noise current is many factors lower than with an ordinary straight cable.