Design of a Microstrip Line Quad-band Bandpass Filter based on the Fibonacci geometric sequence

The following paper presents the development of a set of filters developed with microstrip line technology and dimensions based on the initial terms of the Fibonacci sequence. Simulations of four versions of this filter are made in a circuit analysis tool and they are compared with each other, to choose one of these as the one that offers better attributes. The fourth version of the filter has characteristics of a quadband band passband filter. Finally, the authors expose the results of the simulation, proposing the narrowing of the selectivity factor of the designed filter through other simulations before the measurement of experimental results. The best transmission levels at those four bandwidths are 0.17 dB for 581 MHz in the first bandwidth, 0.52 dB for 1021 MHz in the second, 0.17 dB for 1504 MHz in the third, and 0.20 dB for 2210 MHz in the fourth.