0°-360° wide range digital phase shifters for large array antenna systems

Four different circuit configurations are proposed for designing 0°-360° wide-range, low-loss, loss-balanced phase shifters. Each configuration utilizes three p-i-n diodes. As a consequence of this work construction of 180° phase shifting cells for multibit phase-array antenna systems using three p-i-n diodes has been simplified. Operation of the new circuits is based on the phase shifting properties of symmetric low/high-pass three-element LC ladders. Assuming the utilization of lossless p-i-n diodes and ideal reactive elements, explicit design equations are presented. A numerical method, which includes the diode losses as well as component parasitics, is described for designing practical phase shifters with minimum balanced loss at a given operating frequency. Examples are included to exhibit the use of explicit design formulas, and computer simulations are performed to analyze the loss and phase characteristics of the new circuits. It is expected that the new configurations will find application in the commercial and military large-array antenna systems over the EHF band to be implemented as microwave monolithic integrated circuits