Highly Efficient Transmitter for High Peak to Average Power Ratio (PAPR)

Modern communication systems use complex waveforms that often involve amplitude modulation schemes with a very high peak-to-average power ratio. Therefore, transmitter components often operate at conditions significantly backed-off from their ideal power levels. Functioning over a wide dynamic range of power imposes an undesirable trade-off between efficiency and linearity, both of which need to be maximized for communication transmitters.

Having a high transmit efficiency produces less heat (thermal waste) that leads to improved reliability, longer life, lower operating cost, and reduced power-generation requirements. Operating with peak linearity is essential for clear communication and fast data transfer. Current systems sacrifice efficiency for linear operation and the problem is expected to deepen as crest factor requirements climb.

Optimization Priorities:

• Modulation bandwidth
• Efficiency
• Linearity

Balanced Solution:

Design and deliver innovative ways to improve transmitter efficiency while maintaining linearity for even the most stringent modulation schemes in use today. High-speed (i.e., wide modulation bandwidth) envelope tracking is one technology under investigation that holds great potential for this application. The transmitter will be capable of transmitting over 1-2 octaves at L-Band. It will have 20 MHz of instantaneous operational bandwidth and be capable of transmitting 10 W average power.