12.5mW 48GHz CMOS image-rejection filter with 1GHz tuning range

A large down-conversion of the carrier signal is required in a millimeter-wave receiver. However, since a steep filter in the millimeter-wave band is not available, a heterodyne architecture is commonly used, which increases the power consumption of the receiver. To realize low-power consumption in a millimeter-wave receiver, low intermediate frequency conversion is suitable but requires a millimeter-wave image-rejection filter. In this study, we adopt a high-Q resonator tank enhanced by a negative conductance, using a circuit that includes a transmission line, which defines the signal propagation area of the millimeter wave. As a result, a maximum Q factor of 120, a minimum bandwidth of 0.4 GHz, a maximum gain of 20 dB and a tuning range of 1 GHz are realized with a power consumption of 12.5 mW, where the gain, Q factor and center frequency are tunable by external control. The proposed filter realizes a low intermediate frequency in a millimeter-wave receiver and is expected to contribute to the reduction of power consumption in the receiver.