Abstract: The next-generation communication technology more and more relies on millimeter-wave signal,so the calibration of millimeter-wave signal quality over the air becomes a problem that is urged to solve.In this context,we proposed a W-band wideband vector modulated radiated signal generation method for EVM calibration of OTA millimeter-wave signal and it can provide standard wideband vector modulated signals with high carrier frequency,high transmission rate for EVM calibration of millimeter-wave receivers.By the use of frequency multiplication and frequency mixing,we obtain W-band wideband QPSK vector modulated signals with 1 GBaud(500 MBaud)symbol rate,and then transmit it into the space using an antenna.The receiving antenna receive the signal at the far-filed condition and by the use of down-converter,we finally get the received QPSK signal with 1 GHz carrier.After demodulation the EVM of the signal is about 20 %@1 GBaud(10 %@500 MBaud).To improve the quality of the received signal,we use proper predistortion technology and signal-averaging technology.We estimate the system error combining the transmitted and received signals and then compensate it using iteration method,the EVM drops minimally to 5.2 %@1 GBaud(2.1 %@500 MBaud)which indicates that the signal quality improves significantly.The predistortion signal can be used as high-quality radiated signal for OTA EVM calibration.

Key words: Wideband vector modulated signal, Over-the-air, Error vector magnitude, Predistortion