MINIATURIZED MULTILAYER FILTERS WITH YBa_2Cu_3O_(7-δ) ON LaAlO_3 AND MgO SUBSTRATES

摘要

The need for filter miniaturization without performance degradation has become a critical requirement for the payload of the next generation of communication satellites. Currently, these payloads contain hundreds of filters that are used for frequency multiplexing. Typically, these filters consist of dual mode cavities or dielectric filled resonators which generally are large and heavy. An ongoing effort between the Electron Device Technology Branch of the NASA LeRC and Space System/Loral has resulted in a demonstration of a proof-of-concept (POC) C-band YBa_2Cu_3O_(7-δ) (YBCO) on LaAlO_3 multilayer filter with a raw value for the minimum insertion loss of 0.18 dB at 77 K, 3.81 GHz, and ～3 W input power. Implementing this dual-mode, four pole filter with gold instead of YBCO resulted in a minimum insertion loss of 3.39 dB at room temperature and of 1.61 dB at 77 K at 3.86 GHz and 10 dBm input power. The volume of this filter is ～0.46 cm~3 which is less than 1 percent of the volume of its dielectric counterparts at C-band. The filter was also implemented using MgO substrates, which have a dielectric constant lower than their LaAlO_3 counterparts (9.7 versus 24, respectively). For a YBCO on MgO filter, a raw minimum insertion loss of 0.34 dB was measured at 6.09 GHz and 77 K, while its gold counterpart exhibited 1.86 dB and 1.11 dB at 5.98 GHz at room temperature and 77 K, respectively. The advantages and limitations of this novel filter configuration will be discussed.