Signal combination using bandpass sampling

A signal combination technique, based on the spectral replication property of sampling, is presented. The technique uses second-order bandpass sampling to provide some phase control over the component signals. Although the phase control is not independent between the signals and is constrained by inherent amplitude scaling, quasi-independent control can be achieved. The performance of the combination technique is established for three applications. These applications are diversity antenna combination, interception of slow frequency hopping spread spectrum, and a switchable beam, linear antenna array