A 3.1 to 4.6 GHz 3-bit reconfigurable bandpass filter using λ/4 microstrip resonators and chip inductor coupling

For the efficient use of frequency spectrum resources, RF devices which can flexibly change frequency bands are needed. In the fifth-generation (5G) mobile communication systems, a reconfigurable BPF will be necessary that covers higher frequency bands such as low-SHF bands and enables concurrent dual access by using a high-SHF band. In this paper, a 3-bit/eight center-frequency switchable low-SHF reconfigurable BPF has been designed and fabricated with lumped-element coupling technique. The design and measurement results of the prototype BPF using 03015-type chip inductors are presented as the initial study. The center frequency range of prototype BPF is from 3.1 to 4.6 GHz with insertion loss range from 1.0 to 2.1 dB.