Concurrent dual-band transmitter architecture for spectrum aggregation system

This paper proposes a new transmitter architecture that enables concurrent transmission of two separate frequency bands. This is required in order to realize a spectrum aggregation system. The architecture is based on a delta-sigma (¿¿) modulation which converts a non-constant envelope signal into a constant one. This enables the transmitter to employ a switching power amplifier that has high efficiency. To demonstrate the effectiveness of this architecture, the results of a simulation in which QPSK signals were concurrently transmitted in two bands are presented. In the simulation, the switching amplifier is modeled as an ideal linear amplifier.