A 24-49-GHz CMOS Area-Efficient Phase-Invariant Mixed-Type Attenuator With Capacitive Compensation for 5G New Radio.

This paper presents a 24-49-GHz wideband mixed type attenuator in a standard 65-nm CMOS technology for fifth-generation (5G) new radio (NR) applications. The proposed mixed-type attenuator consists of a 4-bit 7.5-dB reflection-type attenuator (RTA) with 0.5-dB attenuation step and two 7-dB switch-type attenuators (STAs). The capacitive compensation technique is implemented for both attenuators for the phase-invariant attenuation feature. The compact L-C-L matching networks are inserted between each STA and RTA stage to realize the wideband performance. Together with the compact hybrid coupler core of the RTA, the proposed mixed-type attenuator occupies only a 0.037-mm2 core chip area. Within the desired 24-49-GHz band, it realizes a 21.5-dB gain tuning range with 0.5-dB tuning step. The corresponding gain and phase rms errors are less than 0. 36dB and 2.4°, respectively. The measured in-band insertion loss is 4. 9-7.9dB, with a better than 10.5-dB return loss for all attenuation states. No power consumption is required in this work.