Increasing bandwidth can improve output signal to noise of WBFM,but,connot unlimitedly increase bandwidth,to get signal to noise of high frequency.Otherwise it will cause threshold.
黄慎和.论调频接收门限性能[J].重庆工商大学学报(自然科学版),1996,(3): Huang Shenhe. On Threshold in Wideband Frequency Modulation[J]. Journal of Chongqing Technology and Business University(Natural Science Edition),1996,(3):