论文标题
八度带宽毫米波平面矫正器的耐受性分析
Tolerance Analysis of Octave Bandwidth Millimeter-Wave Planar Orthomode Transducer
论文作者
论文摘要
平面矫正器换能器（OMT）通常用于毫米波长下的极化测量。我们提出了基于3D电磁模拟的圆形波导中八度带宽平面OMT的光耦合研究。我们通过诸如共耦合，反射和波导泄漏之类的指标来量化结果，这是OMT构造几何形状的函数。我们评估了这些指标对波导背部距离，探针阻抗，波导间隙的大小和波导到探针的差异的耐受性。研究了两个探针几何形状：以前几个实验中使用的“经典”形状，以及一个新的“酒杯”几何形状。两种优化OMT的带宽比为2.0：1，在共磨耦合超过80％的情况下定义了。经典探针的平均共磨耦合，跨极耦合，反射和波导泄漏分别为93％，$ <$ -50 dB，5％和2％，略微取决于确切的频率范围。 Wineglass探测的共磨耦合为$ \ sim $ 2％。在4％的波导半径水平上的径向波导未对准可能会导致共偏耦合的10％降低10％，并且在一个极化中可下降-20 dB的横切耦合。这些结果可用于指导未来宇宙微波背景实验的检测器模块设计
Planar Orthomode Transducers (OMTs) are commonly used for polarization measurements at millimeter wavelengths. We present an optical coupling study of an octave bandwidth planar OMT in circular waveguide based on 3D electromagnetic simulations. We quantify results through metrics such as co- and cross- polar coupling, reflection, and waveguide leakage as a function of the OMT construction geometry. We evaluate the tolerance of these metrics to the waveguide backshort distance, probe impedance, waveguide gap size, and waveguide-to-probe misalignment. Two probe geometries are studied: the `classic' shape used in several previous experiments, and a new `wineglass' geometry. The bandwidth ratio of both optimized OMTs is 2.0:1, defined where co-polar coupling exceeds 80%. The average co-polar coupling, cross-polar coupling, reflection, and waveguide leakage of the classic probe is approximately 93%, $<$-50 dB, 5% and 2%, respectively and depends slightly on the exact frequency range. The wineglass probe co-polar coupling is $\sim$ 2% larger. Radial waveguide misalignment at the level of 4% of the waveguide radius can result in up to a 10% reduction in co-polar coupling and -20 dB cross-polar coupling in one polarization. These results may be used to guide the detector module designs of future Cosmic Microwave Background experiments and beyond
