  Emerging applications such as wireless sensing, position location, robotics,
and many more are driven by the ultra-wide bandwidths available at
millimeter-wave (mmWave) and Terahertz (THz) frequencies. The characterization
and efficient utilization of wireless channels at these extremely high
frequencies require detailed knowledge of the radio propagation characteristics
of the channels. Such knowledge is developed through empirical observations of
operating conditions using wireless transceivers that measure the impulse
response through channel sounding. Today, cutting-edge channel sounders rely on
several bulky RF hardware components with complicated interconnections, large
parasitics, and sub-GHz RF bandwidth. This paper presents a compact sliding
correlation-based channel sounder baseband built on a monolithic integrated
circuit (IC) using 65 nm CMOS, implemented as an evaluation board achieving a 2
GHz RF bandwidth. The IC is the worlds first gigabit-per-second channel sounder
baseband implemented in low-cost CMOS. The presented single-board system can be
employed at both the transmit and receive baseband to study multipath
characteristics and path loss. Thus, the singleboard implementation provides an
inexpensive and compact solution for sliding correlation-based channel sounding
with 1 ns multipath delay resolution.
