Heterogeneous Integrated Beam-Switching/ Retrodirective Array Using Synthesized Transmission Lines

By utilizing synthesized transmission lines, in this paper a four-element heterogeneous integrated beam-switching/ retrodirective phased array is proposed and demonstrated. Without using active devices, the innovative array can switch its feeding network in two operational modes, making it identical to a beam-switching Butler matrix array in one frequency band, but become a reflection-type retrodirective array in the other band. The key building blocks of the unique feeding network are the dual-mode crossover and dual-mode delay lines, realized by synthesized transmission lines consisting of quasi-lumped meander-line inductors and series LC tanks in microstrip form. The operational principles, including the architecture and phase compensation scheme, are first discussed, followed by the design considerations and experimental results of the core components. The circuit responses of the feeding network and the radiation characteristics of the heterogeneous integrated array are validated through experiments. Discussion is given at the end of this paper.