Nowadays

more and more MMICs (e.g.

limiters and RF switches) have adopted both balanced and unbalanced test pad structures to address the challenging size restrictions and integration requirements of MMICs

which needs hybrid balanced-unbalanced RF probes for on-wafer test. However

the thru standard based on a single balanced or unbalanced structure cannot meet the impedance matching requirement of the hybrid RF probes at the same time

which leads to significant reduction of the calibration accuracy and fails to satisfy the requirement of MMIC test. Therefore

in this paper

the calibration error of hybrid balanced-unbalanced RF probes based on traditional SOLR calibration method is estimated

and an on-wafer test approach of MMICs based on hybrid balanced-unbalanced RF probes is proposed

which combines OSL second-order de-embedding technique with error correction and matrix transformation technique. Meanwhile

we designed an on-wafer test system which consists of a vector network analyzer and SG and GSG RF probes and so on to validate the solution. After vector error correction and de-embedding

the calibration reference plane can be accurately shifted to the probe tip

which greatly improves the test accuracy. In addition

an automatic test system was built by utilizing the object-oriented C# language to improve the efficiency. The program can realize fully automatic operation with instrument control

data acquisition

results correction

data analysis

and so on

which avoids human interference and solves the test efficiency problems faced with the wafer-scale test.