Investigation of leakage in broadband RF and microwave attenuation measurement systems

A simple technique to estimate the attenuation uncertainty due to the leakage in RF and microwave high attenuation is presented. The principle applied in this technique is to execute high attenuation measurements of the device under test (DUT) in networks having phase differences of 0, 90, 180, 270 degrees, created using particular length of addition lines. Investigation on the measurement of 100 dB step attenuator showed the limit of attenuation uncertainty due to leakage is 0.01 dB.