Miniaturized Planar Band-Pass Filter for 5G Applications

This paper explores a compact bandpass filter for low-band 5G base station applications. The proposed filter offers a passband spanning from 450 MHz to 1500 MHz, encompassing critical frequency bands such as n71, n5, n44, and various lower frequency 5G bands. With a remarkable attenuation exceeding 10 dB over the n66, n40, and n41 5G bands, the filter is designed to enhance signal quality within the specified frequency range. Implementation has been achieved on both low-cost FR4 substrate and the widely utilized Rogers R003 substrate. Notably, the substrate dimensions are reduced to a minimal 0.067 lambda(0) x 0.083 lambda(0) x 0.003 lambda(0) (lambda(0) is the free space wavelength at 500 MHz), highlighting the compact nature of the proposed filter.