  This paper considers a network of a multi-antenna array base station (BS) and
a reconfigurable intelligent surface (RIS) to deliver both information to
information users (IUs) and power to energy users (EUs). The RIS links the
connection between the IUs and the BS as there is no direct path between the
former and the latter. The EUs are located nearby the BS in order to
effectively harvest energy from the high-power signal from the BS, while the
much weaker signal reflected from the RIS hardly contributes to the EUs'
harvested energy. To provide reliable links for all users over the same
time-slot, we adopt the transmit time-switching (transmit-TS) approach, under
which information and energy are delivered over different time-slot fractions.
This allows us to rely on conjugate beamforming for energy links and
zero-forcing/regularized zero-forcing beamforming (ZFB/RZFB) and on the
programmable reflecting coefficients (PRCs) of the RIS for information links.
We show that ZFB/RZFB and PRCs can be still separately optimized in their joint
design, where PRC optimization is based on iterative closed-form expressions.
We then develop a path-following algorithm for solving our max-min IU
throughput optimization problem subject to a realistic constraint on the
quality-of-energy-service in terms of the EUs' harvested energy thresholds. We
also propose a new RZFB for substantially improving the IUs' throughput.
