Three-Way Equal Filtering Power Divider for Modern Communication Systems

This article proposes a three-way (3-way) equal filtering power divider (FPD) employing the microstrip compact folded-arms square open-loop resonator (FASOLR). The proposed FPD evenly distributes an input signal into three equal output signals. The design incorporates balanced signal power division, and filtering technology for the removal of unwanted frequency elements and aimed at enhancing signal quality and efficiency in the radiofrequency (RF) front-end of communication systems. The use of FASOLR in the design helps to achieve miniaturization by reducing the device footprint. Keysight's Advanced Design System (ADS) software is used for conducting the design simulations. The proposed FPD features a 2.6 GHz center frequency, with a 0.03 fractional bandwidth. The implementation is carried out on Rogers RT/Duroid 6010LM substrate with a dielectric constant of 10.7, a thickness of 1.27 mm, and a loss tangent of 0.0023. This design includes theoretical calculations, circuit modeling, microstrip layout design, and electromagnetic (EM) simulations. The good agreement between the theoretical and practical results verifies the proficiency of the FPD in delivering equal power outputs at the three output ports, and at the same time filtering out unwanted frequencies as required. The practical responses of the prototype FPD indicate a good return loss of better than 15.5 dB and an insertion loss of better than 4.77 + 0.34 dB. The design prototype achieved a compact size of 0.31 x 0.18 lambda g. The results reinforce the design's competitive edge in performance and actual footprint. lambda g is the guided wavelength for the microstrip line impedance at the center frequency of the three-way equal FPD.