DESIGN OF A TRIPLE-BANDPASS FILTER USING A MODIFIED T-SHAPED RECTANGULAR COUPLED WITH A STEPPED IMPEDANCE RESONATOR FOR SMART PORTABLE COMMUNICATION DEVICE APPLICATIONS

This paper presents a ground-breaking triple-bandpass filter design utilizing a modified T-shape rectangular coupled with a stepped impedance resonator (MTSR-CSIR) for smart portable communication device applications. The MTSR-CSIR filter operates at (2.2, 3.62 and 4.6) GHz, providing wide passbands in three operating modes. To achieve the optimal performance, the filter design is executed on a multi-layered liquid-crystal polymer (LCP) substrate with a thickness of 50 µm, dielectric constant of 2.9 and loss tangent of 0.002. Simulation results for the MTSR-CSIR filter demonstrate a high level of accuracy and consistency with the measurement results for the fabricated filter. The filter exhibits an excellent stopband rejection, low loss and compact size while maintaining high-performance levels. Its performance parameters, such as insertion loss, return loss and group delay, are considered to evaluate the filter’s performance. The results highlight the applicability of the MTSR-CSIR filter for smart portable communication devices.