Abstract: An RJ 45 connector for unshielded CAT5 cable has electromagnetic-interference-suppression circuitry to meet the Class B conducted and radiated emissions standard. The connector comprises, in addition to signal-conditioning transformers, a current-blocking ferrite and a plurality of pairs of common-mode filters, one pair for each conductor of each active twisted pair of the cable. Each pair of filters is connected in series with each other between a conductor of an active twisted pair and a transformer winding, and meets or exceeds the impedance, reactance, and resistance curves of FIGS. 2-4. The ferrite is connected in series with each conductor of each inactive pair of the cable and across a capacitor to ground, and meets or exceeds the impedance, reactance, and resistance curves of FIGS. 5-7.

Abstract: A method and system for reducing the release of high frequency electromagnetic energy into the environment is disclosed, wherein local regions of distributed capacitance are embedded within a printed circuit board (PCB) and adjacent the PCB conductive traces act as low pass filters and thus increase the rise and/or fall times occurring on such traces. The present invention increases very short rise and/or fall times (e.g., 200 picoseconds or less) without degrading or detrimentally affecting other signal characteristics. The present invention does not substantially affect the voltage amplitude and does not affect the bit period when lengthening the rise and/or fall time. Also, the present invention does not induce any timing jitter that may cause synchronization problems within the system.

Abstract: An ultra-high-frequency notch filter (100) comprises a capacitor (102) defining a conductive trace (106) on its body (103) and extending between its terminals (104). The trace has an inductance that forms a parallel LC circuit with the capacitance of the capacitor. When mounted on a printed circuit board (120) to connect two segments of a signal line (124), the notch filter and a ground plane (122) of the PCB form a virtual conductive loop having an inductance and a capacitance whose product is the center frequency of the notch of the notch filter. The center ferquency is tuned by varying the width of the trace.