Compact Dual-Band Microstrip Array Feed Network Using CRLH-TL Power Dividers

This paper introduces a novel, dual-band, compact 1:4 feed network employing a parallel power divider architecture designed to operate at 0.915 and 2.44 GHz, covering both industrial, scientific, and medical and ultra high frequency bands. The design leverages the non-linear phase characteristics of composite right/left-handed transmission lines to achieve dual-band functionality with high precision. Simulation results confirm the efficacy of the proposed network, which delivers quadrature-phase outputs with a 90° phase shift and uniform power distribution across all output ports, facilitating wideband circular polarisation in array antenna applications. Compared to traditional series power dividers, the parallel power divider offers significant advantages in terms of fabrication simplicity, reduced size, and lower manufacturing costs. The design avoids the use of non-radiating composite right/left-handed transmission lines and addresses impedance-matching challenges through the implementation of only three resistors, effectively isolating the output ports. The proposed architecture is highly scalable and can be easily adapted to various output port configurations, frequencies, and power division ratios, offering broad flexibility for a wide range of microwave applications.