Abstract: An adaptive electromagnetic interference (EMI) detection and reduction device for multi-port applications is provided. The invention includes at least two physical devices (PHY), where the PHYs transmit data along wire pairs to a register jack (RJ). The transmissions create EMI along the wire pairs, where the transmissions have constructively interfering resonant frequencies having phases and amplitudes. An antenna is disposed proximal to each RJ, where the antennae detect each frequency. A resonating network determines a peak amplitude of each frequency, an envelope detector amplifies each peak amplitude from the resonating network. A discretization circuit converts the amplified peak to discrete amplitude values, where the discretization circuit transmits the discrete amplitude values to a controller.

Abstract: A low spur phase-locked loop (PLL) architecture is provided. A frequency-synthesizing PLL that includes a differential Kvco gain linearization circuit with adjustable DC offset is used to reduce clock jitter. The free-running oscillation frequency of the VCO of the PLL is centered near the desired frequency using programmable loads to minimize the required control voltage range. The PLL uses a differential architecture that includes a charge pump that compensates for variations in Kvco and a LC tank oscillator with differential controlled varactor. The differential PLL architecture demonstrates that the reference spur can be well controlled to below ?80 dBc.

Abstract: Combined echo and crosstalk cancellation is provided. Frequency domain adaptive filters are used to remove or reduce the effects of echo and crosstalk for a multi-channel and full-duplex communications system. Data from each transmit channel is buffered and converted to the frequency domain. The frequency domain data is multiplied by crosstalk coefficients to obtain a frequency domain correction signal for each channel. Adaptation of the crosstalk coefficients is based on correlations between the error signals and the data from each of the transmit channels. A single frequency domain transform engine, such as a Fast Fourier Transform engine, is employed for all calculations to save power and area.