Design of all-in-one 2SB mixer for ALMA Band 10
Design of all-in-one 2SB mixer for ALMA Band 10
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ALMA Band 10 一体式 2SB 混音器设计
DOI：
10.1117/12.2562032
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Uzawa Yoshinori
中科院分区：
文献类型：
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作者：
Fujii Yasunori;Kojima Takafumi;Kroug Matthias;Uzawa Yoshinori
设计了一种尺寸为22 mm × 27 mm × 11 mm的小型化780-950 GHz边带分离（2SB）超导体-绝缘体-超导体（SIS）混频器。在该混频器模块中，集成了射频（RF） 90°混合耦合器，本振（LO）功率分配器，两个本振耦合器，两个相同的SIS芯片和中频（IF） 90°混合耦合器等所有组件。为了最小化射频信号路径的波导长度，我们将波导组件的放置位置平行地分成两层。一层包含射频混合和低电平耦合器，另一层包含位于射频混合耦合器上方的低电平功率分配器。它们通过导线放电加工制成的波导连接在一起。我们进行了三维电磁模拟，并证实了结果。此外，设计了一个4-12 ghz中频90°混合耦合器，用于组合来自每个SIS芯片的中频信号，该耦合器采用具有相对较高介电常数的氧化铝衬底集成在混频器块中。制备的2SB SIS混频器的单边带噪声温度初步测试结果部分符合当前阿塔卡马大毫米波/亚毫米波阵列（ALMA）规范，无需在接收机前进行损耗校正。由于混频器模块的RF和LO接口与当前ALMA波段10混频器模块相同，因此预计波段10墨盒将升级到2SB配置，而不会对光学器件进行重大更改。
A compact 780–950 GHz sideband separating (2SB) superconductor-insulator-superconductor (SIS) mixer measuring 22 mm × 27 mm × 11 mm is designed in this study. In this mixer block, all components such as a radio frequency (RF) 90° hybrid coupler, a local oscillator (LO) power splitter, two LO couplers, two identical SIS chips, and an intermediate frequency (IF) 90° hybrid coupler are integrated. To minimize the waveguide length for the RF signal path, we separate the placement of the waveguide components into two layers in parallel. One layer contains the RF hybrid and LO couplers, and another layer contains the LO power splitter located above the RF hybrid coupler. They are connected by waveguides fabricated via wire electric discharge machining. We performed three-dimensional electromagnetic simulations and confirmed the results. Furthermore, a 4-12-GHz IF 90° hybrid coupler to combine the IF signals from each SIS chip is designed with an alumina substrate having a relatively high dielectric constant to be integrated in the mixer block. The preliminary test result of single sideband noise temperatures of the fabricated 2SB SIS mixer partly complied with the current Atacama Large Millimeter/submillimeter Array (ALMA) specifications without any loss correction in front of the receiver. Because the RF and LO interfaces of the mixer block are the same as that of the current ALMA band 10 mixer block, band 10 cartridges are expected to be upgraded to 2SB configurations without significant changes in optics.