60 GHz transmitter beamforming front-end IC for radar and communication

Abstract

The 60 GHz frequency band with a wide bandwidth may have a high data rate in communication and an increased distance resolution in radar. However, the 60 GHz frequency band has a large attenuation characteristic in the atmosphere, and accordingly, the SNR decreases. To increase the SNR, beamforming technology is being studied. In this thesis, a study on the transmitter front-end IC for beamforming is conducted. Phase shifter adapts a pair of RF-DAC structures for each turn on and off complementarily. This makes the input and output impedances invariant to control states, which are significant characteristics of reducing the phase shifter's RMS gain and phase errors. The RF-DAC cell is implemented with body floated FETs to reduce the Cds at on and off cells for high gain. The proposed I/Q signal generator is implemented by inserting an R-L polyphase filter into the inter-stage node of a cascode amplifier, which provides good inter-stage matching and results in a finite gain in the I/Q generator. In a power amplifier, linearization techniques are essential to get high linear output power. Linearization techniques that dynamically neutralize the parasitic capacitor and dynamically controlled matching network at the cascode internode are proposed. A 1-channel transmitter beamforming front-end IC composed of a phase shifter and a power amplifier is implemented, and a 4-channel transmitter beamforming front-end IC is implemented. A test module is implemented to verify the 4-channel transmitter beamforming front-end IC, and its performance is verified through free space measurements.