Research And Design Of Power Dividers Based On Lattice-type Slow-wave Transmission Lines

With the rapid development of modern communication technology,the miniaturization of equipment has become an important development trend.Since the size of microwave passive devices is related to the wavelength of electromagnetic waves,the slow-wave structure can reduce the phase velocity of the electromagnetic waves flowing through the dielectric substrate and reduce its guided wave wavelength.Therefore,the slow-wave structure can be applied to the miniaturization design of microwave passive devices.In addition,the higher harmonics will seriously affect the quality of the system and interfere with the normal work of the system.Therefore,how to suppress the higher harmonics has become an urgent problem while miniaturizing the system.As an important part of RF devices,power splitters are widely used in various RF front-end and balanced systems.It is of great research significance to design a miniaturized power splitter with harmonic suppression effect by using slow wave structure.And the main research contents of this article are as follows:1.Using the complementary characteristics of the phase shift of the traditional ?-type slow wave unit network and the X-type unit network,combining ?-type and X-type element networks to form a lattice-type slow wave element network.Based on the serpentine line structure and interdigitated capacitor structure,a lattice-type slow wave transmission line with only a single layer circuit is realized on the coplanar waveguide(CPW).Apply the designed transmission line to the miniaturized design of Ttype power splitter and Wilkinson power splitter,and the designed T-type power divider has a working frequency of 0.9 GHz and a size of 20.9 mm×30 mm,which is only 34.1% of the size of traditional structure.The designed Wilkinson power divider measures 21.9 mm×30 mm,which is only 35.7% of the size of the traditional structure.2.In order to introduce a new transmission zero point to suppress the third and fifth harmonics and realize a lattice-type slow wave transmission line with harmonic suppression characteristics,can continuing to load the LC parallel resonant circuit on the basis of the first cross-type slow wave transmission line.The slow wave transmission line is applied to the harmonic suppression design of T-type power divider and Wilkinson power divider.The designed T-type power divider has a working frequency of 0.9 GHz and a size of 25.3 mm×28.2 mm,which is only 38.8% of the size of the traditional structure.The suppression effects on the third and fifth harmonics are 21 d B and 24 d B,respectively.The designed Wilkinson power divider has a size of 26 mm×28.2 mm,which is only 39.9% of the size of the traditional structure,and the third and fifth harmonic suppression effects are 25 d B and 26 d B,respectively.