Scalable Phased Array Architectures With a Reduced Number of Tunable Phase Shifters

A new architecture for scalable phased array design is presented. A vector summation technique is used in a new feed network in order to reduce the number of tunable phase shifters in the phased array. As a result, phased array front-end’s complexity is reduced. In this architecture, one tunable phase shifter and ${N}$ variable gain amplifiers (VGAs) adjust the phase and amplitude of the signal at each antenna element in an ${N}$ -element subarray. The technique allows a number of subarrays to be connected together to form a larger array providing a narrow beamwidth. An optimum design based on a particle swarm optimization algorithm is presented for an ${N}$ -element subarray. As a proof of concept, an eight-element transmit phased array consisting of two four-element subarrays is designed and tested at the Ku-band based on the described method. Measurement results for the eight-element phased array are presented. The eight-element phased array controlled by two phase shifters and eight VGAs provides approximately 37° of scan range.