Abstract:
A multi-layer printed circuit board is constructed to suppress radio frequency interference (RFI) generated by high frequency clock and data signals therein. Suppression is achieved by positioning clock lines (254) carrying the clock signal on a first voltage reference layer (152) proximate to a second voltage reference layer (154). The two layers shield the clock signal from the signal lines on other layers. Noise may be further reduced by forming bridges (270) in the second voltage reference layer (154) proximate to the clock lines so that the bridges (270) span the width of the clock line. Capacitors are also preferably utilized to further suppress radiated noise. The capacitors provide AC coupling between the first and second voltage reference layers (152, 154) so that a low impedance path is provided for high frequency noise generated by the clock signal. The second voltage reference layer (154) thus operates as an effectively continuous shield between the bridges (270).
Abstract:
On a produit une carte de circuits imprimés multi-couches permettant de supprimer les brouillages radio-électriques (RFI) créés par les signaux d'horloge et de données de hautes fréquences se trouvant dans ladite carte. La suppression est obtenue par positionnement de lignes d'horloge (254) portant le signal d'horloge sur une première couche (152) de tension de référence proche d'une seconde couche (154) de tension de référence. Les deux couches protègent le signal d'horloge des lignes de signaux se trouvant sur d'autres couches. On peut réduire davantage le bruit par formation de ponts (270) dans la seconde couche (154) de tension de référence proche des lignes d'horloge, de sorte que lesdits ponts (270) couvrent la largeur de la ligne d'horloge. On utilise également de préférence des condensateurs destinés à supprimer davantage le bruit émis. Les condensateurs assurent un couplage en courant alternatif entre les première et seconde couches (152, 154) de tension de référence, de sorte qu'un chemin de faible impédance est ménagé pour le bruit HF généré par le signal d'horloge. Ainsi, la seconde couche (154) de tension de référence fait office de blindage effectivement continu entre lesdits ponts (270).
Abstract:
In a microwave device, for example a microwave local oscillator with a harmonic mixer for feedback control, problems of coupling the mixer circuit to the R.F. cavity (10) are overcome by providing a d.c. blocking capacitor of the mixer on a planar surface of a support (20) extending across an aperture (14) in one wall of the cavity. In preferred embodiments the capacitor is a planar device formed by a plurality of interdigitated fingers (26, 28). These fingers (26, 28) are oriented to couple magnetically with the R.F. energy at the aperture in the cavity (10). The support conveniently comprises a printed circuit board having a ground plane (22) on the same surface as the capacitor, which is located in a small opening (24) in the ground plane. A second ground plane (38) is provided on the opposite side of the printed circuit board, overlying the opening. The two ground planes are interconnected by plate-through-holes (40).
Abstract:
Disclosed herein are printed circuit boards (PCBs) (100) with patterned ground structure filters and data storage devices comprising such PCBs. Each PCB comprises a resonator (120) having an L-shape or a zig-zag shape in a plane of the printed circuit board and at least one signal trace (110). The resonator has a first dimension (122) and a second dimension (124) in the plane of the printed circuit board. A portion of the at least one signal trace is situated over the resonator and is separated by a distance from the resonator by a dielectric material. In some embodiments, at least part of the portion of the at least one signal trace extends in a same direction as the first dimension (in the case of an L-shaped resonator) or tracks the zig-zag shape of the resonator (in the case of a zig-zag-shaped resonator).
Abstract:
Die Erfindung betrifft einen Schaltungsträger (11) mit einer Digitalschaltung, die mindestens zwei Bauelemente (12, 14) enthält, die elektrisch miteinander verbunden (19, 21, 20) sind. Zusätzlich ist eine elektrische Schirmung (24) vorgesehen. Erfindungsgemäß ist vorgesehen, dass die elektrische Schirmung (24) sowie ein Leitpfad (21) zur elektrischen Verbindung der Bauelemente (12, 14) durch einen einzigen Schichtverbund (18) realisiert sind. Insbesondere sind die elektrische Schirmung (24) und der Leitpfad (21) durch dieselbe elektrisch leitfähige Lage ausgebildet, wobei eine Freistellung (25) für eine komplette elektrische Isolation des Leitpfades (21) gegenüber der Schirmung (24) sorgt. Gegenstand der Erfindung ist außerdem ein Verfahren zur Herstellung eines solchen Schaltungsträgers.
Abstract:
In a printed wiring board including a first wiring layer and a second wiring layer provided via an insulator layer, at least three guard ground wirings extending along a pair of signal wirings provided in the first wiring layer and supplied with a ground potential are provided between the pair of signal wirings. Thus, crosstalk noise can be reduced without widening a wiring area between the pair of signal wirings.
Abstract:
An LED module includes an LED circuit board that is substantially fully metallized on two opposing surfaces for a number of closely-packed, high-output LEDs, along with an adjacent, parallel circuit board to carry high-frequency drive circuitry for the LEDs. The improved LED light source can provide longer LED lifespan, better wavelength stability, and higher density packaging than convention LED modules. An improvement of 10°C in heat dissipation has been demonstrated over conventional printed circuit boards, and operation at frequencies above 2 MHz for 12 closely-packed, high-output, through-hole mounted LEDs. Continuous temperature monitoring is provided using an on-board calibrated integrated circuit thermistor. In one embodiment, 12 LED's are integrated into a 35 x 30.5 x 30.5 mm aluminum housing for a module that provides 100 mW of filtered light with full-depth AC modulation at 2+ MHz.
Abstract:
A multilayered printed wiring board, a multilayer PWB, and a method for manufacturing the same. The multilayer PWB comprises a first main surface (201) and an opposing second main surface (202), where the multilayer PWB has a height (h) being defined, by the distance from the first main surface to the opposing second main surface. The two surfaces and the height together define the thickness of the multilayer PWB. The multilayer PWB comprises a reference ground plane, a microstrip conductor (210) separated from the reference ground plane (230') by a first dielectric layer (250) and a stripline conductor (220) connected with the microstrip conductor and being separated from the reference ground plane (230' ') by a second dielectric layer (260). The reference ground plane is formed by two or more different partial reference (230',230' ') ground planes positioned at different layers of the multilayer PWB. Furthermore, the reference ground plane is moveable from the first partial reference ground plane to the second partial reference ground plane when a signal current transits from the microstrip conductor to the stripline conductor, and vice versa.