Bandwidth limitations of phase-conjugate arrays used for multipath focusing

This work explores the bandwidth limitations of phase-conjugate arrays used as a multiple access technique in an indoor, multipath-rich environment. A single, phase-conjugating array with two sets of complex coefficients was used to create separate communications channels to receivers located approximately one half wavelength apart and operating at the same frequency. Results are presented showing the variation in the multipath enhanced spatial focusing across the bandwidth of the signals. Our results indicate that, with a four-element transmit array, the isolation between the two channels was measured to be about 10 dB over a bandwidth of 15 MHz.