Improved notch filter for microwave plasma diagnostics in 70 GHz range
Improved notch filter for microwave plasma diagnostics in 70 GHz range
复制标题
改进的陷波滤波器，用于 70 GHz 范围内的微波等离子体诊断
DOI：
10.1088/1748-0221/10/12/c12014
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发表时间：
2015
影响因子：
1.3
通讯作者：
and Y. Yamaguchi
中科院分区：
文献类型：
--
作者：
M. Nishiura;S. Kubo;K. Tanaka;S. Kobayashi;K. Okada;K. J. Okada;T. Nishimura;T. Mushiake;T.Shimozuma;T. Mutoh;T. Saito;Y. Tatematsu;and Y. Yamaguchi
开发了 70 GHz 范围内的陷波滤波器，以消除使用毫米波进行等离子体诊断时不需要的信号。我们需要陷波滤波器具有稳健且窄带的特性。由于我们之前报道的陷波滤波器包含杂散陷波，因此改进了柱塞以减少杂散陷波。有损盘填充柱塞和腔体之间的间隙。有损磁盘的插入最大限度地减少了 76–78 GHz 附近的杂散陷波，而插入损耗在 77.5 至 80 GHz 频率范围内增加。带差动螺钉的柱塞也用于使调谐精细。为了进一步提高性能，在相同腔模的基础上，将耦合狭缝的设计修改为耦合孔。在耦合孔情况下的仿真结果预测，在最大衰减时，在− 3 dB 带宽下，频率小于 50 MHz，在两个腔体中小于− 50 dB，在八个腔体中小于− 100 dB。
A notch filter in 70 GHz range is developed to eliminate undesirable signals for plasma diagnostics using millimeter waves. We require a robust and narrow band characteristic for the notch filter. Since the previous notch filter which we reported contains the spurious notches, the plungers are improved to reduce the spurious notches. The lossy disks infill the gaps between the plungers and the cavities. The insert of the lossy disks minimizes the spurious notches around 76–78 GHz, while the insertion loss increases in the frequency range from 77.5 to 80 GHz. The plungers with differential screws are also used to make the tuning fine. For further performance increase, based on the same cavity mode, the design of coupling slits is modified to coupling holes. The simulated results in the case of coupling holes predict the characteristic of less than 50 MHz at− 3 dB bandwidth and less than− 50 dB with two cavities and− 100 dB with eight cavities at the maximum attenuations.