Investigação na Espessura de Substrato em Híbridas em Quadratura de Baixo Custo Usando FR-4

Development of quadrature hybrid based on low cost materials and fabrication techniques, using ADS and CST softwares, for operation in the UHF Digital TV frequency band in Brazil (470 MHz to 806MHz). The structure consists of superposition-coupled microstrips, plus extra end fitting to ensure better 50Ω matching. Models with different substrate thickness are designed, composed of 1.6mm FR-4 layers. The models are simulated, tested experimentally, and demonstrate the possibility of obtaining these system elements through low cost materials.