Impedance matching pads use a resistive design to achieve the impedance change. Impedance matching transformers use a reactive design (often with a wire-wound toroid) to achieve the impedance change.

3) What are the pros and cons of impedance matching transformer versus impedance matching pads?

Matching Transformer Pros	Matching Pad Pros
Low insertion loss	Wide frequency band (and works at DC)
-	High power capabilities
Matching Transformer Cons	Matching Pad Cons
Narrow frequency band	High insertion loss
Low power	-

4) What are feedthru terminations?

A 50 Ohm feedthru termination is used to connect 50 Ohm RF cable to the high impedance inputs of test instruments (oscilloscope) and maintain proper impedance loading of the RF cable.