  Preserving beam quality during the transportation of high-brightness electron
beams is a significant and widespread challenge in the design of modern
accelerators. The importance of this issue stems from the fact that the quality
of the beam at the accelerator's output is crucial for various applications,
including particle colliders, free-electron lasers, and synchrotron radiation
sources. The coherent synchrotron radiation (CSR) effect can degrade beam
quality when a bunch is deflected. Therefore, developing a structure that
effectively suppresses the CSR effect, especially for the short bunches is
critically important. This involves protecting both the transverse emittance
and the longitudinal profile to ensure the production of a high-quality beam.
In this study, an optimization based on the reverse lattice of the beamline is
proposed. This method can simplify the optimization process. Based on this
approach, the Quadruple Bend Achromat (QBA) deflection structure has been
designed and optimized. Then we have derived a general solution to completely
suppress the impact of steady-state CSR on the transverse plane for different
topologies of QBA. Furthermore, a general condition is proposed for suppressing
displacements caused by CSR in sequence drifts for isochronous structures.
Simultaneously, QBA has proven to be the simplest structure that can
simultaneously suppress both types of CSR effects. Simulation results for
bunches with a peak current of up to $3000A$ show almost no change in
transverse emittance for a large angle deflection.
