Planar power divider design for 5G compatible sub-6 GHz IoT applications

In this thesis, in order to reduce the size of conventional Wilkinson power divider circuits, 2-, 4- and 8-way Wilkinson power dividers are designed by using transmission lines having the effects of slow-wave obtained from the inductively loaded by using narrow slits or meandered lines instead of on their quarterwavelength transmission lines. In addition, novel Wilkinson power dividers are also designed to obtain the different power dividing between the input/output ports, which are constructed by using the proposed quarter-wavelength meandered transmission lines in different configurations. Firstly, two identical 3-way Wilkinson power dividers with 1/2, 1/4 and 1/4 power ratios are developed on the single substrate and then two identical 3-way power dividers having these power ratios are designed by located the quarter-wavelength meandered transmission lines on the different layers as multi-layer applications with the double substrates having the common ground plane. In the two-layer applications constructed on a double substrate, because the power dividers with the independently input/output ports have a very compact size as two different circuits located on different layers, a miniaturization having approximately 1/2 ratio is achieved. These the power dividers use the common ground plane. In the next step, a 5-way Wilkinson power divider having power ratios of 1/2 and 1/4 on one layer and 1/8, 1/16 and 1/16 on the other layer is designed as another example of multilayer application. The proposed Wilkinson power dividers have the potential to be used in only antenna arrays requiring different input/output power ratios and different port arrangements and but also both in the feeding of multiport devices and the filtering of desired frequency bands. In studies on the power divider designs; firstly, the operation frequency band is determined and secondly the required miniaturization and impedance values with relation to the slow-wave effect are theoretically calculated. Thirdly, Wilkinson power dividers having the best performance are determined by means of the Full-Wave Electromagnetic Simulator and finally selected dividers are manufactured and measured for the experimental studies. All manufactured dividers are designed to have a center frequency of approximately 2 GHz. The theoretical, measurement and simulation results are in good agreement. In experimental studies, the insertion and the reflection losses, isolation between the input/output ports and the amplitude differences between output ports are performed. Finally, the proposed Wilkinson power dividers can easily be used in IoT applications below 6 GHz in 5G standards