System and method for active diplexers

#The present invention relates to methods and systems for signal filtering in electronic devices and more particularly, some embodiments related to methods and systems for filtering radio frequency (RF) signals.

#With the many continued advancements in communications and data transfer technology, more and more devices are being introduced in both the consumer and commercial sectors with advanced, high bandwidth communications capabilities. Additionally, advances in processing power and low-power consumption technologies have led to the proliferation of communications capabilities in various products on a widespread basis.

#To address the growing demand for a digital home networking market, a consortium of industry leading companies formed the Multimedia over Coax Alliance, or MoCA™. The MoCA protocol distributes digital entertainment over available bandwidth on the coaxial cable that is installed in households for cable or satellite TV service. The initial MoCA specification was approved in February 2006, and routers with built-in MoCA capabilities, MoCA set-top boxes and MoCA adapters followed shortly thereafter.

#The present invention, in accordance with one or more various embodiments, is described in detail with reference to the following figures. The drawings are provided for purposes of illustration only and merely depict typical or example embodiments of the invention. These drawings are provided to facilitate the reader's understanding of the invention and shall not be considered limiting of the breadth, scope, or applicability of the invention. It should be noted that for clarity and ease of illustration these drawings are not necessarily made to scale.

#FIG. 1a is a diagram illustrating an example implementation of a receiver front end with feedback.

#FIG. 1b is another diagram illustrating an example implementation of a receiver front end with feedback.

#The figures are not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be understood that the invention can be practiced with modification and alteration, and that the invention is only limited by the claims and the equivalents thereof.

#The present invention relates to methods and systems for signal filtering in electronic devices and more particularly, some embodiments related to methods and systems for filtering radio frequency (RF) signals. For example, some embodiments are used for filtering in a home networking system. One such example home network is Multimedia over Coax Alliance (MoCA). In various embodiments, MoCA is used with Community Antenna TV, or Cable TV (CATV) and Fiber to the Home (FTTH) systems. It might also be used in other applications, including other home networking applications.

#FIG. 5 is a diagram illustrating an example of an active band-stop filter with tunable center frequency and adjustable bandwidth. Referring now to FIG. 5, in various embodiments, the filtering circuit 500 is a closed loop system utilizing negative feedback to performing a signal filtering function. The filtering circuit 500 accomplishes signal filtering by performing a direct frequency down-conversion of an input signal. This down-conversion is to zero IF and may use I and Q mixers 502. Additionally, these mixers are driven by quadrature oscillator 504. The filtering of the signal at the converted zero IF frequency is accomplished using integrator 508.