A 4-Element 4-Beam Ka-Band Phased-Array Receiver Using Mesh Topology in 65 nm CMOS

Phased array technique has been widely applied in wireless and satellite communications due to its high spectrum efficiency and system reconfigurability. To maximize the communication capacity, multi-beam phased-array transceivers have drawn more attention in recent years, which enable concurrent communication with multiple independent users at different locations. To achieve the highest beamforming gain and the largest antenna aperture, the fully-connected phased-array is preferred. The conventional fully-connected network based multi-beam topology is shown in Fig. 1 top. As the increase number of elements (N) and beams (M), a total number of M x N amplitude-phase-control channels are needed. In [1], an 8-element 2-beam phased array is reported. However, this architecture is difficult to extend to more beams due to the complexity of local-oscillator (LO) distribution network. A 2-element 4-beam phased-array architecture with the differential passive combining network is proposed in [2]. However, the power-combining network occupies large chip area and the path layout will be more complex when extending to a larger scale.