Abstract: In order to expand the working bandwidth of the IC-stripline, based on the standard IEC61967-8 to improve on the EM601-6 IC-stripline, this paper analyses the working principle and design principle of the IC-stripline, and calculates the size of the septum under the condition of good impedance matching. A method of chopping the transverse current is proposed and a 3D simulation model of the IC-stripline cell is established in the 3D electromagnetic simulation software (CST). The S-parameter and voltage standing wave ratio (VSWR) of the improved IC-stripline are calculated and the calculation results show that the usable frequency of upper limit of the IC-stripline with the slotted septum is increased from 6 GHz to 7 GHz. Although the return loss and insertion loss of the manufactured IC-stripline cell are worse than the simulation results, the working bandwidth is increased from 0−6 GHz to 0−7 GHz within the range required by the standard.