2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/174126We create a Josephson parametric amplifier from a transmission line resonator whose inner conductor is made from a series SQUID array. By changing the magnetic flux through the SQUID loops, we are able to adjust the circuit's resonance frequency and, consenquently, the center of the amplified band, between 4 and 7.8 GHz. We observe that the amplifier has gains as large as 28 dB and infer that it adds less than twice the input vacuum noise.9 pages, 4 figures, submitted to Applied Physics LettersSuperconductivityMesoscale and Nanoscale Physicstext