PSO/FDTD Optimization Technique for Designing UWB In-Phase Power Divider for Linear Array Antenna Application

This letter presents the design of a compact planar in-phase power divider with ultrawideband (UWB) performance. The device consists of three T-shaped microstrip lines arranged in parallel to each other on one side of the dielectric substrate that are electromagnetically coupled with an H-shaped slot etched on its ground plane. Particle swarm optimization (PSO) and the finite-difference time domain (FDTD) are combined to achieve the optimal power divider design for a given specification. The measured results show the transition of the signal between the T-shaped microstrip line and the ground-plane slot divides power equally, with relatively low insertion loss, good return loss, high stability of phase, and high isolation between the two output ports across the UWB frequency band defined between 3.1-10.6 GHz. The power divider is compact in size, occupying an area of 15 × 32 mm². These features make it suitable for linear array antennas.