A transmission line impedance compensation method includes the step of providing a measurement device that is adapted to source a test signal having a frequency to a device under test and to determine a corresponding impedance of the device under test using an auto-balanced bridge technique. A first transmission line, a second transmission line, a third transmission line, and a fourth transmission line are connected to said measurement device. An end of the first transmission line is connected to an end of second transmission line. An end of third transmission line is connected to an end of fourth transmission line. A combined phase delay of the connected first and second transmission lines, and a combined phase delay of the connected third and fourth transmission lines, are measured by the measuring device. The device under test is connected to the first transmission line, the second transmission line, the third transmission line, and the fourth transmission line after measuring the phase delays. The corresponding impedance of the device under test is determined based on both of the phase delays.