This paper presents the design of novel microwave bandpass filters, composed of coupled single-mode triangular resonators, in microstrip technology. Based on the study through electromagnetic-field simulation on the couplings between pairs of such openloop triangular resonators and between a single resonator and its 50 Ω feeding line, microwave bandpass filters with various specifications can be developed, for telecommunications and radar applications. Here, two bandpass filters with different types of couplings between resonators are designed, fabricated and tested. The electrical performances of the experimental models meet the specification, which validates and proves the flexibility of the design of bandpass filters composed of coupled triangular microstrip resonators.

Keywords: Resonator, Microstrip technology, Bandpass filters, Couplings, Microwaves