发明名称 Apparatus and method for filtering voiceband and metering tone frequencies of a mixed voice/data signal
摘要 An apparatus and method provide for filtering of voiceband and specified tone frequencies of a mixed voice/data signal, such as an Asymmetric Digital Subscriber Line (ADSL) signal. A lowpass filter section passes voiceband content of the mixed signal and suppresses mixed signal content having frequencies falling within a databand of the mixed signal. A bandpass filter section is coupled to or integral with the lowpass filter section and passes the specified tone frequency, such as a metering or billing tone frequency. The lowpass and bandpass filter sections exhibit a combined frequency response that provides for a stopband between the voiceband and the metering tone frequency. The bandpass filter section effectively detunes a frequency response of the lowpass filter section to provide for the stopband. The stopband preferably provides for an insertion loss of 3 dB or greater between the voiceband and the metering tone frequency, and suppresses undesirable mixed signal content having frequencies falling within the stopband. The lowpass filter section and the bandpass filter section may each be implemented to include only passive components, such as passive magnetic components.
申请公布号 AU5758001(A) 申请公布日期 2001.09.17
申请号 AU20010057580 申请日期 2001.03.09
申请人 ADC TELECOMMUNICATIONS INC. 发明人 STEVEN M. SWAM
分类号 H04M11/06 主分类号 H04M11/06
代理机构 代理人
主权项
地址