Millimeter-wave beamforming front-end IC for 5G communication

Abstract

The need for various millimeter-wave (mm-wave) frequency band systems, including mm-wave 5G, the Internet-of-things (IoT), automotive radar, and imaging, has accelerated the research of mm-wave transceivers. A phased array system, which uses multiple antenna and multi-channel RF front-end chip, has been used to overcome high path loss of mm-wave frequency bands. Therefore, a multi-channel RF beamforming front-end chip has become an essential component in mm-wave communication and radar applications. In this dissertation, millimeter-wave beamforming front-end ICs for 5G NR FR2 bands are presented. To implement the simple and high-performance beamforming front-end unit-channel IC, gain control function distribution and embedded switch concepts are proposed. Gain control function is added to the power amplifier, low noise amplifier, and Tx/Rx phase shifters instead of using the variable gain amplifier or attenuators. Transmit/receive switches are embedded into the PA, LNA, and phase shifters' matching networks to reduce the overall size and insertion losses. With unit-channel IC, we further integrated the 4-channel beamforming front-end IC with differential power divider and additional gain amplifier chain for driving high power to the power divider's input. By adopting the differential structure to the lumped-element based power divider, we can achieve a low-loss compact four-way power divider with the robust operation for the ground parasitic inductances. Then, we implement the 64-channel beamforming module using 16 four-channel beamforming front-end ICs. This module operates with the 100-m over-the-air (OTA) measurement with 64-QAM 5G NR signal and achieves high EIRP (Effective Isotropically Radiated Power) with beam-steering. Besides, to cover the wide frequency spectrum of 5G NR FR2 (24-30 GHz and 37-43.5 GHz), a multi-band four-way differential power divider and multi-band low noise amplifier are proposed. Using the switched coupled inductor and switched capacitor, frequency reconfigurable multi-band operation is achieved.