Design six-port reflectometer based on inductively-compensated coupled lines

The aims of this paper are to study the impact of directivity to the performance of an Engen's six-port reflectometer (SPR) and propose a simple technique based on inductive compensated coupled lines for an SPR design. Comparison of the performances of the SPR with compensated and uncompensated coupler designs is made at 2.4 GHz frequency. Based on the calculation data, the SPR with an inductive compensated coupler achieves small measurement error which is less than 5%.