Newbie level 3
I need help .. I need to design a dual band antenna with a dielectric using HFSS .. i tried and tried and just can't get the dimensions right .. I used a DRA cut in half with a radius of 5 mm and height of 17.85 mm . I got these numbers using some formula i found in a book that my teacher gave me ... The goal is to have a dual band antenna between 880-960 Mhz and 1710-1880. The results are way way off ... what should i do ? what should i change ? if i change the dimensions nothing much happens .. In my results i got very high frequencies 10 14 Ghz .. i'm out of ideas . help !