Observed polarization degree (upper panel) and flux (lower panel) as a function of time for the power-law jet model at observed frequency ν = 10¹⁵ Hz (PLS G) with a flat initial Lorentz factor distribution (b = 0) and a random magnetic field structure, confined to the shock plane (ξ → 0). The various values of a represent different slopes for the power-law jet wings. The observer is located at q = 0.7.