Low-noise submillimeter-wave NbTiN superconducting tunnel junction mixers
Low-noise submillimeter-wave NbTiN superconducting tunnel junction mixers
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DOI：
10.1063/1.125522
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发表时间：
1999-12
影响因子：
4
通讯作者：
J. Kawamura;Jian Chen;David P. Miller;J. Kooi;J. Zmuidzinas;B. Bumble;H. Leduc;J. Stern
中科院分区：
文献类型：
--
作者：
J. Kawamura;Jian Chen;David P. Miller;J. Kooi;J. Zmuidzinas;B. Bumble;H. Leduc;J. Stern
利用NbTiN薄膜微带调谐电路和混合Nb/AlN/NbTiN隧道结，研制了一种低噪声850 GHz超导体-绝缘体-超导体准粒子混频器。混频器采用准光学结构，平面双缝天线馈入双结调谐电路。在798 GHz，我们测量了未校正的双边带接收机的噪声温度TRX = 260 K，在4.2 K浴温度。该混频器在800 GHz附近的性能几乎是当前Nb SIS混频器的2倍。在800 GHz处的高间隙频率和低损耗使得NbTiN成为制造SIS混频器调谐电路的有吸引力的材料。NbTiN混频器可以潜在地工作在高达差距频率2Delta/h~ 1.2THz。
We have developed a low-noise 850 GHz superconductor–insulator–superconductor quasiparticle mixer with NbTiN thin-film microstrip tuning circuits and hybrid Nb/AlN/NbTiN tunnel junctions. The mixer uses a quasioptical configuration with a planar twin-slot antenna feeding a two-junction tuning circuit. At 798 GHz, we measured an uncorrected double-sideband receiver noise temperature of TRX = 260 K at 4.2 K bath temperature. This mixer outperforms current Nb SIS mixers by a factor of nearly 2 near 800 GHz. The high-gap frequency and low loss at 800 GHz make NbTiN an attractive material with which to fabricate tuning circuits for SIS mixers. NbTiN mixers can potentially operate up to the gap frequency, 2Delta/h~1.2 THz.