A Fully Integrated Pulling Mitigation Synthesizer for NB-IoT Transmitter

This article presents the pulling mitigation scheme implemented in the frequency synthesizer integrated with the dual-band narrowband-internet-of-things (NB-IoT) transmitter (TX). The proposed pulling mitigation in the synthesizer employs a hybrid phase compensation and sampled filter to mitigate the pulling effects by the transmitter. The synthesizer covers frequencies from 700-900 MHz and 1.7-2 GHz in the low band and high band, respectively, satisfying the dual-band NB-IoT frequency tuning specifications. The proposed pulling mitigation in the synthesizer improves the error vector magnitude (EVM) by 11.5% with 16 quadrature amplitude modulation (QAM) modulation and in single-tone measurements, the achieved pulling suppression is 24 dB. Implemented in 40 nm CMOS, the pulling mitigation occupies a small area of 0.18 x 0.18 mm(2) and the dc power consumption is 1 mW with a supply voltage of 1.1 V.

Automated summary

This article introduces a pulling mitigation scheme implemented in a frequency synthesizer integrated with a dual-band NB-IoT transmitter (TX). The scheme utilizes a hybrid phase compensation and sampled filter to mitigate the pulling effects caused by the transmitter. The synthesizer covers frequencies from 700-900 MHz and 1.7-2 GHz in the low and high bands respectively, meeting the dual-band NB-IoT frequency tuning specifications. The proposed pulling mitigation improves the EVM by 11.5% with 16QAM modulation, achieving a pulling suppression of 24 dB in single-tone measurements. Implemented in 40 nm CMOS, the pulling mitigation occupies a small area of 0.18 x 0.18 mm² and consumes 1 mW of DC power with a 1.1 V supply voltage.