Band-Selectable CMOS SPDT Switch With Reconfigurable Magnetically Coupled Inductors for Multiband 5G NR Applications

This article presents the design of a band-selectable switch for 5G New Radio (NR) multiband (MB) transceiver applications. To achieve high isolation (ISO) and impedance matching across low-band (LB) (24–29 GHz) and high-band (HB) (37–40 GHz) operations, a reconfigurable magnetically coupled inductor structure is proposed. The mutual inductance polarity of the inductors is configured to be positive or negative depending on the operating band, enabling band-specific resonance through the combination of magnetic coupling and parasitic capacitances. The switch is implemented in a 65-nm RFCMOS process. Measurement results show that the proposed switch achieves ISO greater than 36.6 dB and insertion loss (IL) less than 2.37 dB in the LB mode, and ISO greater than 33.3 dB and IL less than 3.28 dB in the HB mode.