To meet the ever-increasing demand for data transmission rates,expanding the bandwidth and increasing the number of antennas are direct and effective means.Driven by 6G application scenarios and key capabilities,the 6425~7125 MHz frequency-band(U6G)extra-large scale multiple-input multiple-output(MIMO)technology becomes a candidate enabler to meet the requirements of 6G.Based on the RF and channel characteristics,the overall design goal of efficient U6G extra-large scale MIMO is proposed,to address the challenges in cost,overhead,and complexity.Finally,future research trends are discussed.