  Relativistic jets from supermassive black holes are among the most powerful
and luminous astrophysical systems in Universe. We propose that the open
magnetic field lines through the black hole, which drive a strongly magnetized
jet, may have their polarity reversing over time scales related to the growth
of the magneto-rotational dynamo in the disc, resulting in dissipative
structures in the jet characterized by reversing toroidal field polarities,
referred to as ``stripes''. Magnetic reconnection between the stripes
dissipates the magnetic energy and powers jet acceleration. The striped jet
model can explain the jet acceleration, large-scale jet emission, and blazar
emission signatures consistently in a unified physical picture. Specifically,
we find that the jet accelerates to the bulk Lorentz factor $\Gamma \gtrsim 10$
within one parsec distance from the central engine. The acceleration slows down
but continues at larger distances, with intrinsic acceleration rate
$\dot{\Gamma}/\Gamma$ between $0.0005~\rm{yr^{-1}}$ and $0.005~\rm{yr^{-1}}$ at
tens of parsecs, which is in very good agreement with recent radio
observations. Magnetic reconnection continuously accelerates nonthermal
particles over large distances from the central engine, resulting in the
core-shift effect and overall flat-to-inverted synchrotron spectrum. The
large-scale spectral luminosity peak $\nu_{\rm peak}$ is anti-proportional to
the location of the peak of the dissipation, which is set by the minimal stripe
width $l_{\rm min}$. The blazar zone is approximately at the same location. At
this distance, the jet is moderately magnetized, with the comoving magnetic
field strength and dissipation power consistent with typical leptonic blazar
model parameters.
