Densely Interleaved Arrays for Dual-Tone Transmitters

Power amplifier nonlinearity introduces intermodulation distortion when transmitting dual-tone signals from an antenna array. To reduce distortion levels and increase output power for dual-tone systems we propose to densely interleave two antenna arrays without increasing the antenna aperture. Each array is excited with a different tone, resulting in a single-tone input for the power amplifiers, thereby reducing intermodulation distortion. In order to compare the performance of the densely interleaved array with a regular, planar array, when excited by two-tone signals, a procedure for evaluating the S-parameters matrix of an interleaved dipole array is presented. Simulations with a realistic RF power amplifier model show 13 to 31 dB intermodulation reduction for the same output power and total antenna aperture