;In this study, a miniaturized dual-band switched beamforming module is proposed.First,a miniaturized 1.8/5.8 GHz 4 × 4 Butler matrix is presented,which is achieved by using dual-band bridged-T coils to replace the λ/4 lines for circuit size reduction and dual-band operation. In addition,when feeding a 4 × 1 linear antenna array ,it can achieve the same beam direction at the two operation frequencys.The proposed dual-band Butler matrix is implemented in a integrated passive device process,and the chip size is only 10 mm × 5 mm,which corresponds to an electrical size of 0.1λ0 × 0.2λ0 at 5.8 GHz.Second,a DC-6 GHz absorptive SPQT switch is realized,which is designed using a series-shunt configuration and resistors.It is implemented in a GaAs pHEMT process,and the chip size is 1.5 mm × 1 mm,while the electrical size is 0.029λ0 × 0.01λ0 at 5.8 GHz.It can be used with the proposed 4 × 4 Butler matrix to form a compact dual-band switched beamforming model.
