Keysight (formerly Agilent)'s E4438C ESG vector signal generator combines outstanding RF performance and sophisticated baseband generation to deliver calibrated test signals at baseband, IF, and RF frequencies up to 4 GHz. Featuring an internal baseband generator with arbitrary waveform and real-time I/Q capabilities, ample waveform playback and storage memory, and a wide RF modulation bandwidth, the E4438C ESG is equipped to test today's complex wireless systems and their components. The E4438C ESG is an adaptable platform with optional capabilities to customize the instrument for baseband and RF test applications ranging from simple distortion test and general purpose troubleshooting to baseband coding algorithm development, advanced transceiver design verification, and high volume manufacturing. Its modular architecture makes it easy to configure the instrument with the level of performance and signal creation capability you need today with the option to upgrade in the future.