小时带积5μS声表面波色散延迟线

小时带积线性调频信号由于其频谱非常严重的菲涅尔波动,从理论上限制了压缩脉冲的旁瓣电平,而实际器件由于受制作工艺和声表面波二阶效应的影响,旁瓣电平抑制还会差些。用“反波动设计法”制作的器件旁瓣电平有较大的改善,但同时多普勒频移(fD)敏感度的增大却又限制了它的应用范围。 本文简要报道利用一般的设计方法,在器件设计制作上作一些特殊考虑,研制出时带积为27的低旁瓣电平及对多普勒频移敏感度较小的声表面波色散延迟线,并给出了器件的性能参数和波形。

5us SAW Dispersive Delay Line with Small Time Bandwidth Product

Since the large Fresnel ripple in the spectrum of small time bandwidth product FM signals, the sidelobe levels in compressed pulse are limited theoretically. Furthermore; because of the limitation of manufacture technique and the SAW second effect, the sidelobe-level suppression for practical devices is even worse. A big improvement of sidelobe levels has been achieved for the devices made with reciprocal ripple design method, however, the increased doppler frequency shift sensitivity may be unacceptable in many applications. This paper briefly described a new developed SAW dispersive delay line with lower sidelobe levels and small sensitivity to doppler frequency shift, using conventional design method with special attention to the device fabrication. The paper also gave the performance parameter and waveform of the devices,