Test Platform for Millimeter-wave Amplifier Linearity Characterization

Many existing and proposed military satellite communication waveforms use spectrally confined modulations to increase the number of users that occupy a limited bandwidth. These modulations are non-constant modulus and require linear operation of the transmitters. Linearity requirements necessitate that amplifiers operate well below their saturated output power, which often requires devices larger in size and weight than acceptable for mobile terminals, such as those in vehicles. The Lincoln Laboratory Amplifier Testbed (LLAT) is a measurement platform designed to quantify the effects of amplifiers on spectrally confined waveforms. LLAT is capable of measuring amplifiers at millimeter-wavelengths with saturated output powers ranging from a few Watts to hundreds of Watts. To allow maximum flexibility in modem design, LLAT uses virtual modems running on a multiprocessor grid. The LLAT enables investigation of technology advances that may solve the size, weight and power constraints of small mobile terminals.