  Reconfigurable Intelligent Surfaces (RISs) exhibit promising enhancements in
coverage and data rates for wireless communication systems, particularly in the
context of 5G and beyond. This paper introduces a novel approach by focusing on
the design and prototyping of a transmissive RIS, contrasting with existing
research predominantly centered on reflective RIS. The achievement of 1-bit
transmissive RIS through the antisymmetry configuration of the two PIN diodes,
nearly uniform transmission magnitudes but inversed phase states in a wide band
can be obtained. A transmissive RIS prototype consisting of 16 $\times$ 16
elements is meticulously designed, fabricated, and subjected to measurement to
validate the proposed design. The results demonstrate that the proposed RIS
unit cell achieves effective 1-bit phase tuning with minimal insertion loss and
a transmission bandwidth of 3 dB exceeding $20\%$ at 5.8GHz. By dynamically
modulating the quantized code distributions on the RIS, it becomes possible to
construct scanning beams. The experimental outcomes of the RIS-assisted
communication system validate that, in comparison to scenarios without RIS, the
signal receiving power experiences an increase of approximately 7dB when RIS is
deployed to overcome obstacles. This underscores the potential applicability of
mobile RIS in practical communication.
