Millimeter wave AlGaAs/InGaAs 2DEG-CCDs

A two-phase, InGaAs channel 2DEG-CCD (charge coupled device) intended for millimeter-wave signal acquisition and delay is presented. Signal delay versus clock frequency has been measured from 1 MHz to 14 GHz, verifying CCD operation. The input-to-output transfer function is linear with a 1 dB compression point at 2 dBm and a 3rd harmonic intercept at 35 dBm. A charge transfer efficiency (CTE) of 0.99 has been measured at 4.73 GHz. Two-dimensional transient simulations show that the charge packet transfers at saturation velocity, and that CTE degradation results primarily from charge trapping in interelectrode parasitic wells. The simulations predict that CTE greater than 0.9999 is achievable at clock frequencies up to 50 GHz.<>