N-Way Parabolic UWB Planar Spatial Power Divider/Combiner

• Published in: IEEE transactions on microwave theory and techniques Vol. 73; no. 5; pp. 2766 - 2775
• Main Authors: Yanegh, Ayoub, Ghadimi, Ali, Baladi, Elham
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2025; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Amplitudes; Current distribution; Cylindrical to plane wave conversion; Cylindrical waves; Focusing; Frequency conversion; Frequency ranges; Impedance; Lenses; mmW; Particle swarm optimization; phase and amplitude balance; Phase shift; planar spatial divider/combiner; Plane waves; Power combiners; Power dividers; Power transmission lines; Propagation losses; Simulation; Straight lines; Surface waves; Transmission line measurements; Transmission lines; Traveling waves; Ultra wideband technology; Ultrawideband; ultrawideband (UWB) divider/combiner; Wave diffraction
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2024.3476310

In this article, a 1-to-N parabolic ultrawideband (UWB) planar spatial power divider/combiner is designed and implemented. In this structure, the signal from one port (port 1) passes through a parabolic-shaped transmission line to N parallel ports (ports <inline-formula> <tex-math notation="LaTeX">2~\rightarrow ~N +1 </tex-math></inline-formula>), which are positioned in a straight line at equal distances from each other. Due to diffraction, the traveling wave from port 1 will be cylindrical, and this parabolic-shaped transmission line converts the cylindrical wave into a plane wave at the N parallel ports. To accurately evaluate the performance of the divider/combiner, a new method is proposed by defining a parameter called <inline-formula> <tex-math notation="LaTeX">S_{\mathrm { error}} </tex-math></inline-formula>. The simulated results obtained for a 1-to-4 divider/combiner within the frequency range of 15-60 GHz [120% bandwidth (BW)] indicate that the amplitude difference between ports is less than 2.4 dB, and the phase difference is less than 8°. To further enhance the amplitude and phase balancing, the shape of the transmission line, responsible for converting the cylindrical wave to a plane wave, is optimized using the particle swarm optimization (PSO) algorithm and simulation by MATLAB-HFSS API. The optimized results for a 1-to-4 divider/combiner within the frequency range of 15-60 GHz demonstrate an amplitude difference of less than 0.75 dB between the ports and a phase difference of less than 2.5°.