Development to achieve uniform circular polarisation in designing a Cavity Backed Spiral antenna (1-18GHz).

Description

The existing antenna exhibits weak radiation pattern formation up to 2GHz, dip in power levels at bore-sight beyond 13GHz and elliptical polarization all over the frequency band leading to degradation in system Direction finding (DF) accuracy.  To improve DF accuracy, it is mandatory to maintain radiation pattern similar to Gaussian like curve along with uniform polarization characteristic. This improvement needs to be achieved without any deviation to overall dimension of the antenna including radome.