those before as shown in fig1 a and 19b while most of the current flows along the wire some current follows along the twist fig2 a and 20b show cross sectional views of the currents flowing on the twisted stranded wires at 25 ghz and 40 ghz respectively the results in fig2 a and 20b are similar to those in fig1 a and 18b and no substantial change is noticed due to the twisted wires compared to the solid wires fig2 a and 21b show the effect of the twist angle on the amount of current flowing to the back of the wires the results indicate that higher twist angle leads to more currents flowing to the back of the wires overall it appears that a combination of the high frequencies and the twist of the strands may be the cause of this phenomenon i e seeing through the wires with parallel polarization furthermore the combination of the tire carcass layer and the nst layer beneath it can create a resonant condition e g cavity that can further enhance detection the effect of bulging due to the inserts may also contribute to the ability to image variations at the location of an insert these results are preliminary and further investigation is needed to understand fully this phenomenon to do so additional simulation and experimental verification is required to optimize the frequency and imaging technique through the tire carcass layer however it appears that when the selected location on the tire to be imaged contains stranded reinforcements such as the cables and cords commonly used in tires then it is advantageous to select a polarization parallel to the longitudinal direction of the reinforcements a method of tire inspection using microwave imaging was developed and.