  A new Doppler backscattering (DBS) system, consisting of Q-band and V-band,
has been installed and achieved its first data on the MAST-U spherical tokamak.
The Q-band and V-band have separate microwave source systems, but share the
same optical front-end components. The Q-band and V-band sources simultaneously
generate eight (34, 36, 38, 40, 42, 44, 46 and 48 GHz) and seven (52.5, 55,
57.5, 60, 62.5, 65 and 67.5 GHz) fixed frequency probe beams, respectively.
These frequencies provide a large range of radial positions from the
low-field-side edge plasma to the core, and possibly to the high-field-side
edge, depending on the plasma conditions. The quasi-optical system consists of
a remotely-tunable polarizer, a focusing lens and a remotely-steerable mirror.
By steering the mirror, the system provides remote control of the probed
density fluctuation wavenumber, and allow the launch angle to match the
magnetic field. The range of accessible turbulence wavenumbers (k_\theta) is
reasonably large with normalized wavenumber k_\theta\rho_s ranging from <0.5 to
9. The first data acquired by this DBS system is validated by comparing with
the data from the other DBS system on MAST-U (introduced in Ref. [21]). An
example of measuring the velocity profile spanning from the edge to the center
in a high-density plasma is presented, indicating the robust capabilities of
the integrated Q-band and V-band DBS systems.
