This paper describes the design and implementation of a 39 GHz 256-element hybrid active phased array antenna system with 16 individual digital transceivers, and its wireless multi-user, multi-input, multi-output verification. An earlier version of this paper was presented at the 2021 51st European Microwave Conference and was published in its Proceedings [1]. Using the prototype device, a single carrier transmission test assuming a mobile backhaul link and a MU-MIMO transmission test using a zero-forced orthogonal multi-beam based on channel reciprocity assuming an access link was performed. As a result, an EIRP of 43 dBm and a data rate of 5.5 Gbps in 1 GHz bandwidth single carrier 128QAM operation and an estimated total throughput of 2.4 Gbps by 3GPP TS38.214 [2] in 100 MHz bandwidth OFDM 8 MU-MIMO operation were achieved, respectively. As far as the author knows, this is the first demonstration for integrated access and backhaul (IAB) application that uses the 39 GHz band.