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横向波滤波器已经用微型超导抽头延迟线实现。由于超导体的损耗低,这就有可能采用小型带状线结构在微波频段提供有效延迟。抽头延迟线是以回波耦合器或以阻抗间断形式来实现的。Chirp(线性调频滤波器)是用这样一些耦合器级联起来增加长度的办法组成的。在2.6GHz带宽内做了脉冲展宽和压缩实验。通过给这些抽头加权,可使旁边电平的减小,比峰值输出低26dB。应用耦合模的分析来预测这种滤波器的响应特性,其分析结果与实验非常符合。分析还表明,如果加强耦合使插入损耗减小约10dB,就会产生明显相位畸变,旁边的电平同时成比例地减小。已经提出一种计算方法,根据它来调整抽头的位置,以便用补偿抽头重加权引起的畸变来预先修正相位响应。对经预先修正的器件的进一步分析表明,在插入损耗为3dB的汉明(Hamming)加权滤波器中,旁边的相对电平能够达到41dB。这种技术可用于声波滤波器和光栅滤波器。
Transverse wave filters have been implemented with miniature superconducting tap delay lines. Due to the low loss of superconductors, it is possible to provide an effective delay in the microwave band using a small stripline structure. The tapped delay line is implemented as an echo coupler or as an impedance discontinuity. Chirp (Chirp Filter) is a cascade of such couplers to increase the length of the composition. In the 2.6GHz bandwidth pulse stretching and compression experiments done. By weighting these taps, the side level reduction can be as much as 26 dB below the peak output. The coupled mode analysis is used to predict the response of this filter. The analysis results are in good agreement with the experiment. The analysis also shows that if the coupling is increased and the insertion loss is reduced by about 10 dB, significant phase distortion will occur, with the levels next decreasing proportionately. A calculation method has been proposed according to which the position of the tap is adjusted so that the phase response is corrected in advance by compensating for the distortion caused by the tap weighting. Further analysis of the pre-corrected device shows that the relative level next to it can reach 41 dB in a Hamming weighting filter with an insertion loss of 3 dB. This technique can be used for both acoustic and grating filters.