Design of 1:4 Power Divider for Space Applications

This paper presents a novel implementation of a compact 4-way microstrip Wilkinson power divider operating in the S-band (2-4 GHz), specifically designed for space and IoT applications. The novelty of this work lies in achieving a balanced performance between bandwidth, miniaturization, and cost-effectiveness using an economical FR-4 substrate, addressing the common trade-offs found in conventional designs where one parameter is typically compromised. A comparative study was initially conducted using four 2-way dividers simulated across FR-4 and Rogers5880 substrates, each evaluated with both sharp and curved geometries. While the Rogers-sharp combination yielded the smallest footprint, the FR-4 sharp configuration was selected for fabrication due to its cost-effectiveness and competitive performance characteristics. This design approach is particularly advantageous for systems where compactness, low cost, and acceptable RF performance are essential requirements. The fabricated divider occupies a compact area of only 51 mm × 31 mm (1581 mm²) and demonstrates excellent performance metrics. The device achieves a simulated fractional bandwidth of approximately 58.4% and a measured fractional bandwidth of 66.67% at 3 GHz. Key performance parameters include return loss exceeding -13.33 dB, insertion loss around -0.6 dB, and isolation of approximately 12.18 dB without requiring additional resistors. The measured maximum phase imbalance between output ports is limited to 2.045°, supporting coherent output distribution across all channels. Compared with recent works in the literature, this design offers a significant balance of bandwidth performance, area miniaturization, and practical manufacturability. The proposed divider is specifically optimized for ISM-band and IoT-based RF front-end systems where cost-effective compact components are essential for widespread deployment and commercial viability.