Dear all,
i study a paper which teach make the UWB 3dB coupler. and it use a slot-coupling approach. the coupler consists of three conductor layer interleaved by two dielectric. the top and bottom are conductor layers, mid-layer is a slot ground. However, i dont know the concept how it can make the bandwidth be wider.
and my tutor give me a hints , he said i can use electric length to think of it...but i still do not have any idea...hope someone can teach me,thx^^