Codebook beam characterization approach with dual band for 6G 140 GHz, 300 GHz UE array

Abstract

Experimental results from 5G FR2 CATR OTA measurement practices, this paper outlines beam codebook design for a mobile UE operating at 140 GHz and 300 GHz. The modeled UE uses two dual band antenna modules, one on the rear and one on the side edge. Each module contains a shared 2 × 5 array with 0.5 mm element spacing, approximately half a wavelength at 300 GHz. The modem controls beam steering and selects the active module. Under the assumed element pattern model, beamwidths are 139.3° at 140 GHz and 65° at 300 GHz, with estimated peak element gains of 3.28 dBi and 9.90 dBi, respectively. Three methods are compared using the spherical EIRP CDF: (a) a single beam per module with jointly optimized steering, (b), a dense uniform codebook with jointly optimized scan ranges and beam overlap, and (c) a gap directed codebook that adds beams to improve the current 10th percentile EIRP. At 140 GHz, the gap directed method achieves 17.57 dBm using 30 beams, compared with 17.51 dBm using 110 dense codebook beams. At 300 GHz, it achieves −0.32 dBm using 30 beams, compared with −0.15 dBm using 486 beams. These results show that the gap directed method approaches dense codebook performance at the 10th percentile while reducing beam count by approximately 3.7× and 16.2× at the two bands.