Simultaneous Transmission of Non-Contiguous Frequency Bands using a Pulse-Width-Modulated Switch-Mode Stage

The following paper demonstrates the capability to support simultaneous transmission of non-contiguous frequency bands for the pulse-width-modulator and a single switch-mode stage with two signals spaced 1GHz apart, each of them meeting the 3GPP ACLR requirements. We use a fast PWM to convert the analog signal to a digital signal that can be handled by the switch-mode stage. Moreover, we present a pulse-widthmodulated current-mode class-S power amplifier designed for a carrier frequency of 2600MHz. The complete class-S amplifier is characterized using a clipped single-carrier WCDMA signal at 2600MHz. The measured spectrum at the amplifier's output meets the 3GPP ACLR requirements within outstanding 10dB output power range. Index Terms -- Class-S amplifier, GaN-MMIC, linearity, pulse-width-modulation, switch-mode operation. #