DESIGN AND IMPLEMENTATION OF T SHAPED RESONATOR MICROWAVE LOW PASS FILTER FOR COVID 19 TEMPERATURE MONITORING

This paper shows the design of microstrip low pass filter (LPF) using T-shaped resonator having wide stopband. The structure is composed of rectangular patches, substrate and ground plane. The T shaped resonator has FR4 Epoxy(relative permittivity of 4.4 and tangent loss of 0.02) dielectric substrate with 1.6mm thickness which is of miniature in size, low cost and to obtain best filter characteristics based on S-parameters. The physical size of ground plane and substrate are of same dimensions 20mm x 15.5mm.The implemented and simulated LPF using Ansys HFSS has a center frequency(f0) 2.8 GHz, where the measured values of the insertion loss is above -3db and the return loss is below -10db.The measured results has good advantages of low insertion loss and high return loss. This shows the method of transforming conventional lumped elements into microstrip line is able to resolve complexity of circuit design. The designed LPF can be used in the temperature monitoring using wireless communication for biomedical applications.