As it is known, the measurement of wave impedance of printed circuit boards (PCB) can be executed either directly on the printed-circuit board (if the parameters of the PCB make it possible to carry out such measurement), or on a test coupon, which must be specially prepared for such purpose. The Test coupon can be located directly on the printed-circuit board (if size of PCB allows this arrangement), or it is carry out at an separate board, if it cannot be placed at the PCB. In the second case, the test coupon is placed, as a rule, on the same PCB panel, where main printed circuit board is located. To achieve a good quality of the measurement of wave impedance the PCB designer and manufacturer shall follow the requirements for test coupon design (more details you can see here).