A Design of Microstrip of 180-Degree Hybrid Coupler Using T-Shape Structure for Monopulse Radar

Hybrid couplers offer equal power split and 180 ∘ phase shift between output ports. When the signal frequency decreases, the size of the coupler grows, requiring a reduction in size. T-shaped structures replace each [Formula: see text] section, reducing the overall size. The 180 ∘ hybrid device has benefits like simplicity and isolation, but disadvantages like limited bandwidth and space. It is suitable for various technologies like microstrip line, stripline, waveguide and coplanar waveguide. The electromagnetic simulation, conducted using HFSS, confirms the theory and validates the proposed design of the coupler, hence validating both the design and simulated results. Following the validation in simulation. The 180 ∘ hybrid ring that has a structure in the form of a was fabricated utilizing a cost-effective material and an FR 4 substrate. It was subsequently evaluated using an E5071C Network Analyzer Agilent vector network analyzer. The dimensions of the rat-race coupler utilized are 55.63 or 66.52 (mm 2 ), indicating a reduction of 17.35[Formula: see text] in comparison to the conventional breed. Furthermore, the agreement between the isolation coefficient, reflection and phase difference between the output ports is also favorable.