公开(公告)号：US20070285297A1

公开(公告)日：2007-12-13

申请号：US11760746

申请日：2007-06-09

Applicant: T. S. Venkatesh ,  L. Chandrashekar ,  Prasun Kali Bhattacharya ,  Prasenjit Bhowmik ,  C. Srinivasan ,  Mukesh Khatri ,  Sanjeeb Kumar Ghosh ,  Sumanth Chakkirala ,  Sundararajan Krishnan ,  Prakash Easwaran

Inventor： T. S. Venkatesh ,  L. Chandrashekar ,  Prasun Kali Bhattacharya ,  Prasenjit Bhowmik ,  C. Srinivasan ,  Mukesh Khatri ,  Sanjeeb Kumar Ghosh ,  Sumanth Chakkirala ,  Sundararajan Krishnan ,  Prakash Easwaran

IPC: H03M1/12

CPC classification number: H03M1/0641 ,  H03M1/12

Abstract: A system and method for improving the dynamic performance in an analog-to-digital converter (ADC) by randomizing the differential mismatch. The differential mismatch in an input analog signal is randomized by flipping the input signal and output signal randomly.

Abstract translation: 一种通过随机化差分失配来改善模数转换器（ADC）中的动态性能的系统和方法。 通过随机翻转输入信号和输出信号，输入模拟信号的差分失配被随机化。

公开(公告)号：US07298838B2

公开(公告)日：2007-11-20

申请号：US10234510

申请日：2002-09-03

Applicant: Sandeep K. Oswal ,  Prakash Easwaran ,  Arijit Raychowdhury ,  Fernando A. Mujica

Inventor： Sandeep K. Oswal ,  Prakash Easwaran ,  Arijit Raychowdhury ,  Fernando A. Mujica

IPC: H04M1/00

CPC classification number: H04B3/23

Abstract: A method for reducing transmit echo in a DSL modem comprises selecting at least one cancellation device of a plurality of cancellation devices. An attenuation signal is generated using the selected cancellation device. At least a portion of transmit echo is removed from a receive signal using the attenuation signal.

Abstract translation: 一种用于减少DSL调制解调器中的发射回波的方法包括：选择多个取消装置的至少一个消除装置。 使用所选择的取消装置产生衰减信号。 使用衰减信号从接收信号中去除发射回波的至少一部分。

公开(公告)号：US07177613B2

公开(公告)日：2007-02-13

申请号：US10711680

申请日：2004-09-30

Applicant: Anant Shankar Kamath ,  Gaurav Chandra ,  Prakash Easwaran

Inventor： Anant Shankar Kamath ,  Gaurav Chandra ,  Prakash Easwaran

IPC: H04B15/00 ,  H04B1/10

CPC classification number: H04B1/30 ,  H03F1/26 ,  H03F1/3211 ,  H03F3/45183 ,  H03F3/45475 ,  H03F2200/294 ,  H03F2203/45136 ,  H03F2203/45526

Abstract: A receiver, implemented with low noise and low distortion, to process an input signal containing signals of interest and unwanted interference signal. In an embodiment, the receiver contains a mixer which generates an intermediate signal in the form of an electric current, and a filter which filters the unwanted interference signals from the intermediate signal. The intermediate signal is centered around a lower frequency compared to a carrier frequency of the input signal. Due to the current mode interface between the mixer and the filter circuit, low noise and low distortion may be attained.

Abstract translation: 以低噪声和低失真实现的接收机，用于处理包含感兴趣信号和不想要的干扰信号的输入信号。 在一个实施例中，接收机包含以电流形式产生中间信号的混频器和从中间信号滤除不想要的干扰信号的滤波器。 与输入信号的载波频率相比，中间信号以较低的频率为中心。 由于混频器和滤波器电路之间的电流模式接口，可以获得低噪声和低失真。

公开(公告)号：US07138873B2

公开(公告)日：2006-11-21

申请号：US10904578

申请日：2004-11-17

Applicant: Gaurav Chandra ,  Prakash Easwaran ,  Sumantra Seth

Inventor： Gaurav Chandra ,  Prakash Easwaran ,  Sumantra Seth

IPC: H03F3/04

CPC classification number: H03F1/34 ,  H03G3/3052 ,  H03G5/24 ,  H03H11/126 ,  H03H11/1291

Abstract: A low distortion filter circuit implementing variable gain amplification (VGA). An aspect of the present invention increases the degrees of freedom (number of components which can be independently programmed/changed to corresponding desired values) to achieve a desired combination of D.C. gain and filter characteristics (e.g., corner frequency, Q-factor, notch frequency, etc.). Such additional degrees of freedom are attained by including additional components in either on input block or a feedback block (implemented with reference to an operational amplifier), and by redesigning the other block using principles such as admittance concellation to remove the effects of such additional components. The blocks are designed such that a terminal of the programmable components is connected to a fixed/constant voltage (e.g., ground). Embodiments implementing bi-quad single amplifier with and without notch are disclosed.

Abstract translation: 实现可变增益放大（VGA）的低失真滤波电路。 本发明的一个方面增加了自由度（可以被独立地编程/改变为相应的期望值的分量的数量），以实现期望的DC增益和滤波器特性的组合（例如，转角频率，Q因子，陷波频率 等）。 通过将附加组件包括在输入块或反馈块（参考运算放大器实现）中并且通过使用诸如导纳协调之类的原理重新设计其他块来消除这些附加组件的影响来实现这样的附加自由度 。 这些块被设计成使得可编程组件的端子连接到固定/恒定电压（例如，接地）。 公开了实现具有和没有陷波的双二极管单放大器的实施例。

公开(公告)号：US06804291B1

公开(公告)日：2004-10-12

申请号：US09510085

申请日：2000-02-22

Applicant: Prakash Easwaran ,  Mrinal Das

Inventor： Prakash Easwaran ,  Mrinal Das

IPC: H04B138

CPC classification number: H03M7/3015 ,  H03M7/3026 ,  H03M7/304

Abstract: A sigma delta modulator (350) can be utilized in the Digital-to-Analog (DAC) portion (144) of a modem (120) to achieve a desired level of gain programming. A set of step coefficients (GP2, GP4) are utilized to determined the step size and thereby the overall gain of the modulator (350). A feedback path is provided and configured to deliver the output of the modulator to a gain control block (355) which provides control and stability across the entire transmission bandwidth. A multilevel digital output (320) is provided which represents levels of signal in the digital domain and reduces the number of discrete components required to achieve a particular amount of gain.