A Transmission Double-Line for the Calibration System of X-Band Active Phased-Array Antennas

A transmission double-line, with low attenuation and low voltage standing wave ratio (VSWR) for the calibration of X-band active phased-array antennas, was designed and manufactured. The transfer function from a fed element of active phased-array antennas to the double-line was measured. The transmission double-line is used to monitor and correct the element phase error of an active phased-array antenna. Radiation patterns before compared to after calibration show that the approach is useful.