US 5,500,629 A · Noise suppressor

Abstract

A distributed low-pass filter typically attenuating a signal, 7 db. at 10 MHz., 18 db. at 30 MHz., and continuing at 50 db/decade, without resonant inflections, uses a small, low cost, rectangular tubular bead of outside dimension 3 mm..times.6 mm..times.2 mm., made from a body material having evenly distributed magnetic, dielectric, and resistive properties. A through-conductor completes the distributed filter which acts like a high loss cable transmission line. The tube's inner and outer surfaces are separately coated with an electrode material. The through-conductor electrically connects to the inner electrode, with its ends providing first and second filter terminals, and the outer electrode providing a common, terminal. An a.c. signal impressed between the first and common terminals produces an attenuated signal between the second and common terminals in accordance with the above characteristics. Also, a 6 mm..times.6 mm..times.1 mm block of the body material may typically form a 500 .mu.F power-line, noise suppressor. The above devices may include bi-directional, zener-like, voltage limiter capability; absorbing noise and electrostatic discharges, like varistors. A preferred body material is a sintered mix of oxides of manganese and iron, modified by oxides of zinc, nickel, or other metals. This soft ferrite, ceramic adapts to make surface mounted devices. Small, low cost, RF noise suppressors, line terminators, or impedance matching filters for use in high frequency (baud rate) cable connectors may be molded individually, or integrated as multiple devices.

Claims12

Dependent claims

An electrical noise suppressing component comprising:

a) a body made from a sintered polycrystalline body material having cohesively integrated metal oxide grains, wherein magnetic, dielectric, and resistive properties are substantially evenly distributed throughout the body, providing a minimum body permittivity of 4,000,000 at 1 KHz, and a body resistivity less than 1 M.OMEGA. per cm.;
b) at least one noise suppressing element formed by the body, comprising a first surface being separated from a second surface by an intermediate section of the body material;
c) a first electrode disposed upon the first surface, defining a first area of electrical contact with the intermediate section;
d) a second electrode disposed upon the second surface, defining a second area of electrical contact with the intermediate section.

1 more element

A noise suppressor assembly having a through-passage comprising:

a) a plurality of noise suppressor devices;
b) each said noise suppressor device comprising:
i) a body made from a sintered polycrystalline body material having cohesively integrated metal oxide grains, wherein magnetic, dielectric, and resistive properties are substantially evenly distributed throughout the body, providing a minimum body permittivity of 4,000,000 at 1 KHz, and a body resistivity less than 1 M.OMEGA. per cm.;
and
ii) said body having a first surface and a second surface, said first surface separated from said second surface by an intermediate section of said body material, a first electrode disposed upon said first surface, a second electrode disposed upon said second surface;
and
iii) said body being shaped to form a segment of said noise suppressor assembly, having at least two contact surfaces;
c) each of said noise suppressor devices joining with the other said noise suppressor devices in said noise suppressor assembly via said contact surfaces;
d) said noise suppressor assembly having an inner peripheral surface adjacent said through-passage and an outer peripheral surface, said inner and outer peripheral surfaces being coaxial;
e) said second surfaces of the noise suppressing devices substantially forming said inner peripheral surface;
f) said first surfaces of said noise suppressing elements substantially forming said outer peripheral surface of said filter assembly.

8 more elements

Dependencies are inferred from the claim text.

Noise suppressor

Life of this patent

Noise suppressor

Life of this patent

Abstract

Claims12