Design and validation of a high-efficiency RF amplifier for acousto-optic spectrometers.

This work presents the design and experimental validation of a space-oriented engineering model of a high-efficiency radio-frequency power amplifier (RFPA) for driving acousto-optic tunable filters (AOTFs) in spaceborne spectroscopy and remote sensing payloads. The proposed RFPA represents the first step toward the development of a flight-capable architecture specifically designed to satisfy the stringent power, thermal, mass, and volume constraints of spacecraft while maintaining high radio-frequency (RF) performance. It employs a compact, small-form-factor architecture operating over the 100-150 MHz frequency range and provides continuous output power tunability to accommodate varying mission requirements without compromising RF spectral purity. Experimental characterization demonstrates a sustained power-added efficiency (PAE) exceeding 65% across the operating band, with continuous output power tunability. The amplifier also achieves harmonic suppression of better than -30 dBc, ensuring compliance with spectral purity requirements for sensitive spaceborne instrumentation.