Reconfigurable Power Amplifiers for Spectrum Sharing in Arrays

In a wireless spectrum that continues to grow more crowded, reconfigurable power amplifiers play a significant role in allowing system performance to be optimized while dynamically sharing spectrum. In phased arrays, reconfigurable amplifiers are useful in allowing both spatial and spectral resources to be shared. Recently developed high-power reconfigurable impedance matching networks, using plasma switches, allow the use of reconfigurable power amplifiers in radar transmitters, providing reconfiguration on a pulse-to-pulse basis. Fast tuning algorithms have been designed to allow closed-loop optimization of the tuner settings to maximize output power and range in real time. To allow closed-loop optimization, an in-situ measurement technique allows on-board performance assessment and solves the problem of array calibration in reconfigurable arrays. Challenges and opportunities to complete the design of phased arrays using reconfigurable power amplifiers are discussed through some application examples.