公开(公告)号：US07196574B1

公开(公告)日：2007-03-27

申请号：US11157945

申请日：2005-06-22

申请人： Adam S. Vishinsky

发明人： Adam S. Vishinsky

IPC分类号： H03K5/00

CPC分类号： H03H11/22 ,  H03H11/0444 ,  H03H11/08 ,  H03H2011/0494

摘要： Direct incorporation of transmission zeros into a continuous-time active complex BP filter transfer function yields a filter having much sharper roll-off than that of an all-pole filter. The ladder filter is constructed using transconductors and capacitors only. The filter center frequency, its bandwidth and positions of transmission zeros can be electronically varied using tunable transconductors. The positions of zeros are changed by modifying cross-coupled differential transconductors connected between capacitors in parallel with the series inductors. Since all transconductors used in the filter are electronically tunable an automatic tuning system conveniently adjusts the filter center-frequency and its Q-factor.

摘要翻译： 将传输零直接并入连续时间有源复合BP滤波器传递函数产生的滤波器比全极滤波器具有更尖锐的滚降。 梯形滤波器仅用跨导电容器和电容器构成。 滤波器中心频率，其带宽和传输零点的位置可以使用可调谐的跨导体进行电子变化。 通过修改与串联电感器并联的电容器之间的交叉耦合差动跨导体来改变零点的位置。 由于滤波器中使用的所有跨导体都是电子可调谐的，自动调谐系统方便地调节滤波器中心频率及其Q因子。

公开(公告)号：US07400212B1

公开(公告)日：2008-07-15

申请号：US11146379

申请日：2005-06-07

申请人： Adam S. Vishinsky

发明人： Adam S. Vishinsky

IPC分类号： H04B3/04 ,  H01P1/20

CPC分类号： H03H11/1291 ,  H03F1/3211 ,  H03F3/45475 ,  H03F2200/336 ,  H03F2200/451 ,  H03F2203/45136 ,  H03F2203/45138

摘要： An automatically tuned on-chip active continuous-time real bandpass filter operates on a differential signal while simultaneously being tuned using a common-mode (CM) reference signal, which results in a superior accuracy of its center frequency and bandwidth. The filter consists of two or more pairs of gm-C or other types active resonators that can be single-ended or differential. The two identical filters are tuned with CM reference that is rejected at the output of each pair of resonators. For each pair of resonators, the present frequency-tuning finds the resonant frequency, for which the bandpass (BP) and lowpass magnitude values are equal. For each pair of resonators, the present Q-tuning scheme adjusts BP magnitude at the resonant frequency and its Q to the appropriate value. The present tuning method allows building a reasonably flat passband BP filter using two or more pairs of resonators. Additionally, since both present tuning schemes rely on the amplitude detection the CM reference signal can be made small, which prevents the build-up of the intermodulation distortion in the filter.

摘要翻译： 自动调谐的片上有源连续时间实数带通滤波器对差分信号进行操作，同时使用共模（CM）参考信号进行调谐，从而导致其中心频率和带宽的更高精度。 滤波器由两个或更多对g-m-C或其它类型的可以是单端或差分的有源谐振器组成。 两个相同的滤波器用CM参考调谐，在每对谐振器的输出端被拒绝。 对于每对谐振器，当前的频率调谐寻找到频带（BP）和低通幅度值相等的谐振频率。 对于每对谐振器，本Q调谐方案将谐振频率处的BP幅值及其Q调整到适当的值。 本调谐方法允许使用两对或更多对谐振器构建合理平坦的通带BP滤波器。 另外，由于本次调谐方案都依赖于幅度检测，所以可以使CM参考信号变小，从而防止滤波器中的互调失真的累积。

公开(公告)号：US06930565B1

公开(公告)日：2005-08-16

申请号：US10915487

申请日：2004-08-11

申请人： Adam S. Vishinsky

发明人： Adam S. Vishinsky

IPC分类号： H03J3/08 ,  H04B3/04

CPC分类号： H03J3/08 ,  H03J2200/08 ,  H03J2200/18

摘要： An automatic tuning scheme for two active band-pass filters where both filters operate on the signal while simultaneously being tuned using a reference signal. To allow that the amplitude of a reference signal is made small and since both filters demonstrate a good linearity the build-up of the inter-modulation distortion does not occur. The first band-pass filter is tuned with the reference falling into its pass-band. The second band-pass filter is also tuned with the reference placed into its pass-band. The reference is practically eliminated by the virtue of the complexity of the second band-pass filter. Assuming the filter passes the signal for positive frequencies if the reference is made a negative frequency by appropriate 90 degrees phase shifting it will be attenuated by at least 55 dB, which is a sufficient signal-to-reference ratio.