Such assumptions sometimes may result in narrowfrequency band, large time delay and unstable system.
这样得到的控制系统频带较窄、时滞大，还有可能出现控制系统不稳定。
2
Based on T type filter, the new ballast can achieve a wide dimming range with a very narrowfrequency variation range, and it can operate with low lamp current crest factor.
基于T型滤波器的调光方法，能在很窄的工作频率范围内实现深度调光，同时具有灯电流波峰因数低的优点。
3
The speech is sparse in time-frequency domain, so the energy of voice signal only concentrates on some narrowfrequency, and the energy of voice sources are not overlap each other.