  A study of the gravitationally lensed blazar PKS 1830-211 was carried out
using multi waveband data collected by Fermi-LAT, Swift-XRT and Swift-UVOT
telescopes between MJD 58400 to MJD 58800 (9 Oct 2018 to 13 Nov 2019). Flaring
states were identified by analysing the gamma-ray light curve. Simultaneous
multi-waveband SED were obtained for those flaring periods. A cross-correlation
analysis of the multi-waveband data was carried out, which suggested a common
origin of the gamma-ray and X-ray emission. The broadband emission mechanism
was studied by modelling the SED using a leptonic model. Physical parameters of
the blazar were estimated from the broadband SED modelling. The blazar PKS
1830-211 is gravitationally lensed by at least two galaxies and has been
extensively studied in the literature because of this property. The
self-correlation of the gamma-ray light curve was studied to identify the
signature of lensing, but no conclusive evidence of correlation was found at
the expected time delay of 26 days.
