Error Correction and Power Calibration of Active Load Pull Measurement Systems

A 26.5 to 40 GHz active load pull measurement system has been developed using a commercially available test fixture and bias tees. At 27 GHz, the system is capable of reflection coefficient magnitude accuracy better than 0.007, phase error less than 4 degrees, and gain uncertainty less than 0.15 dB. Reflection coefficient measurements are corrected by flrst using a standard network analyzer TRL calibration routine and then converting it to two one port calibrations. Correction of the power measurements is not as straight forward. Sources of error in the power measurements and methods to reduce this error are discussed.