Frequency-Controlled Fixed-RF Beam-Steering Array Based on Two-Wave Mixing With Cascaded Unequal Power Divider

Abstract

Large-scale phased array now becomes one of the most critical components in wireless communication system. However, the high cost and complexity of the phase controlling in conventional phased array make it difficult to be widely deployed in commercial use. Alternatively, a frequency-controlled beam-steering method with fixed radiation frequency based on sequential mixing of the propagating IF and local oscillator (LO) waves has been proposed as a low-cost solution. The beam pointing direction can be changed by a single-frequency controller rather than varying any phase shifters or tunable components on the antennas. However, this technique relies on accurately splitting the input IF and LO waves to a mixer’s array through all passive power distribution networks. This communication discusses the practical design consideration of a robust two-wave mixing array and two sets of cascaded unequal power dividers are employed to efficiently distribute the IF and LO signals. To ensure constant radiation frequency, an external reciprocal mixer is used to keep the frequency difference between LO and IF being same as the desired RF. The measured result shows that the proposed signal distribution network successfully achieves the desired phase and amplitude of the converted RF signal.