In recent decades, the hairpin topology uses parallel-coupled lines and behaves like a band-pass filter used to isolate the bandwidth's frequencies from parasitic signals. It takes up relatively low board space and is quite easy to build compared to other band-pass microstrip topologies. Despite significant size reduction, existing hairpin bandpass filters exhibited forged harmonics and substantial circuit size, uneven modal imbalance, and faulty outputs. To decipher these issues, a novel Methodical Hairpin Bandpass Filter Design is proposed. Initially Recapitulate Fractal Embracement is adopted in which the fractals are generated using Recapitulate Function System (RFS) for effectively curbing the harmonics. Moreover, the substantial filter size can be reduced by a Pleated hairpin bandpass filter design which deploys pleating the open-end arms symmetrically inwards. This size reduction of the hairpin bandpass filter may tend to the generation of erroneous reflection and transmission coefficients. To tackle this, Adaptive-Radiation Algorithm (ARA) optimization exploiting the vigor functionisproposed. It utilizes a vigor function that appraises the S-parameter in the passband and generates an optimal solution. Consequently, the level of a harmonic of greater than 36 dB is curbed and a size reduction of 28% is obtained thus designing an efficient hairpin bandpass filter.

Keywords: Recapitulate Fractal Embracement, Pleated design, Adaptive-Radiation Algorithm, Vigor function, Forged harmonics.