  Quasi-biennial oscillations (QBOs) are considered as a fundamental mode of
solar magnetic activity at low latitudes ($\leq50^\circ$). However, the
evolutionary aspect and the hemispheric distribution of solar QBOs at high
latitudes ($\geq60^\circ$) are rarely studied. Here, a relatively novel
time-frequency analysis technique, named the synchrosqueezed wavelet transform,
is applied to extract the main components of the polar faculae in the northern
and southern hemispheres for the time interval from August 1951 to December
1998. It is found as the following: (1) Apart from the 22-year Hale cycle, the
17-year extended activity cycle, and the 11-year Schwabe cycle, the QBOs have
been estimated as a prominent timescale of solar magnetic activity at high
latitudes; (2) the QBOs of the polar faculae are coherent in the two
hemispheres, but the temporal (phase) and the spatial (amplitude) variations of
solar QBOs occur unevenly on both hemispheres; and (3) for the 11-year period
mode, the northern hemisphere begins three months earlier than that in the
southern one. Moreover, the spatial and temporal distributions of the
hemispheric QBOs differ from those of the 11-year Schwabe cycle mode in the two
hemispheres. Our findings could be helpful to improve our knowledge on the
physical origin of the spatial distribution of solar QBOs at high latitudes,
and could also provide more constraints on solar dynamo models introduced to
characterize the different components of the solar magnetic activity cycle.
