Field Deployable Microwave Filters Made from Superconductive Thick Films

Radio frequency (RF) resonators are made by depositing thick films of YBa2Cu3O7−δ onto three-dimensional substrates. The superconducting resonators are then coupled together to form high performance RF filters. The topologies and frequency responses of some of these devices are briefly discussed prior to beginning a more detailed discussion aimed at addressing some of the common misconceptions of high temperature superconductive (HTS) thick film devices, namely the nonlinearity and the size. The intermodulation distortion (IMD) is shown to be below the noise floor in most practical applications, and a mathematical model that uses the empirical surface impedance data to predict the behavior of the IMD is described.