Design of U-Shaped In-Phase Power Divider Employing Ground-Slotted Technique for Wideband Applications

This article describes the design of U-shaped wideband power divider implemented with ground-slotted technique. The slotlines at ground plane underneath second and third arm promises wider bandwidth performance. In this proposed designed, the second and third arms are formed by microstrip line with J-shaped slot underneath. In order to obtain the impedance and dimension of microstrip line and slot forming the quarter-wave transformer, the new equation is proposed and discussed in this paper. The relation between characteristic impedance of microstrip-slot transmission line \((Z_{\mathrm{m-s}})\) with slot width \((\hbox {W}_{\mathrm{s}})\) and microstrip impedance \((Z_{\mathrm{m}})\) is obtained by using completing square curve fitting method. To realize the circuit, substrate Rogers TMM4 is used. The thickness of the substrates is 0.508 mm with dielectric constant of 4.5 and 35 \(\upmu \hbox {m}\) cooper coating. The performance of power divider is formulated by using commercially available CST Microwave Studio. The performance of the fabricated device is then compared with simulation. The optimum result has been achieved over wideband frequency with the measured and simulated result show reasonably comparable performance between 4 and 11 GHz.