Enabling 2-D Beamforming for 6G Communication in the D-Band with a Scalable Transmitter MMIC Utilizing On-Chip Antennas

In this work, we present a 2D-scalable architecture for D-band transmitters to enable 6G communication. It allows for arrays that can be extended up to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$8 \times 8$</tex> on a circuit board level. The presented chip houses four transmit channels with on-chip antennas arranged as a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2 \times 2$</tex> array. Thus, requiring a very compact design to encompass the antennas and the active circuitry while still allowing for an antenna spacing of just <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.51 \lambda$</tex> for 2D-beamsteering. Moreover, the chip features a 3-dB bandwidth of 16 GHz, fully covering the potential <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$141-148.5 \text{GHz}$</tex> communication band with a saturated EIRP of up to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3 \text{dBm}$</tex>.