  Fano resonance is believed to arise when a direct path interferes with a
resonant path. We demonstrate that this is not true for chiral electronic
transmission without additional direct paths. To address the Fano effect in
chiral electronic transport, we suggest an electronic Mach-Zehnder-Fano
interferometer (MZFI), which combines a quantum dot with an electronic
Mach-Zehnder interferometer. Backscattering is completely suppressed in chiral
electronic transport, yielding perfect Fano profiles that can be fully adjusted
by an external magnetic flux in the transmission, linear conductance, and
differential spectra. Even the current and shot noise for a symmetric
interferometer with two arms of the same length exhibit fully controllable
resonances and distinct Fano resonance characteristics. Along with the
profiles, all of the transport spectra follow the same evolution pattern in a
cycle that is resistant to changes in the device's defining parameters.
