We develop a phase-space representation concept in terms of the Wigner
function for a quantum harmonic oscillator model that exhibits the
semiconfinement effect through its mass varying with the position. The new
method is applied for the analytical computation of the Wigner distribution
function for such a semiconfinement quantum system. The method allows for
suppression of the divergence of the integrand in the definition of the quantum
distribution function and leads to the computation of its analytical
expressions for the stationary states of the semiconfined oscillator model.
Both cases of the presence and absence of the applied external homogeneous
field for this quantum system are studied. Obtained exact expressions of the
Wigner distribution function are expressed through the Bessel function of the
first kind and Laguerre polynomials. Further, some of the special cases and
limits are discussed in detail.Comment: 10 pages, 9 figure