US 6,504,447 B1Granted

Microelectromechanical RF and microwave frequency power limiter and electrostatic device protection

AssigneeHRL Laboratories, LLC

InventorsDavid Laney, Mehran Matloubian, Lawrence Larson

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Abstract

The present invention provides a flexible mechanical bridge over a microstrip on a substrate, which utilizes an electromagnetic field increase, as generated by temporary power surge to shunt harmful power away from a MMIC system. The invention includes a power limiter which includes an airbridge 11, preferably in the form of an electrically conductive strip with ground contacts 1 and 3 formed thereon. The ground contacts 1 and 2 are electrically connected, through via holes 5 and 7 respectively, to a metallization layer 15 formed on the bottom side of a substrate 9. The air bridge 11 is designed such that it traverses an electrically conductive microstrip 13 forming an air gap 16 between the air bridge 11 and the electrically conductive microstrip 13. When there is a power surge the air bridge 11, will flex to cause an electrical connection with the microstrip 13, thereby directing the unwanted signal through the ground contacts 1 and 3 and the via holes 5 and 7 to the metallization layer 15.

Claims7

Dependent claims

A power limiter having:

a. a substrate having a top side, a bottom side and via holes, the top side of the substrate having ground contacts of an electrically conductive material formed thereon, and the bottom side of the substrate having a ground metallization layer formed thereon, said via holes electrically contacting said ground contacts, and forming openings between the top side and the bottom side of the substrate, said via holes including means by which an electrical connection is formed between the ground contacts and the ground metallization layer;
b. a transmission line in the form of a strip of electrically conductive material formed on the top side of the substrate, said microstrip passing substantially between the via holes;
and
c. an air bridge formed of a substantially elongated strip of an electrically conductive ductile material having end portions and a center portion, the end portions of the strip being electrically and mechanically attached to the ground contacts of the substrate such that the air bridge forms an electrical connection between the ground contacts of the substrate, thereby forming a ground contact, said air bridge further formed such that the center portion is arched upward, passing over the transmission line on the top side of the substrate, forming an air gap therebetween such that when an undesirable signal is generated on the microstrip, the capacitance created causes the air bridge to flex towards the microstrip physically and electrically contacting said microstrip, thus shorting the undesirable signal to ground by passing the signal through the electrically conductive air bridge, through the ground contacts and the via holes to the ground metallization layer.

1 more element

A power limiter including:

a. a substrate having a side with plurality of metallization contacts of an electrically conductive material formed thereon, and a substantially planar transmission line of an electrically conductive material formed thereon, the substantially planar transmission line including a first side and a second side, said plurality of metallization contacts formed such that a portion of the metallization contacts reside on either side of the transmission line;
and
b. a resilient substantially arc-shaped strip including at least one layer of electrically conductive material electrically and mechanically connected to a portion of the plurality of metallization contacts on both sides of the substantially planar transmission line and positioned so that a portion of the substantially arc-shaped strip is adjacent to the substantially planar transmission line and so that a gap is formed therebetween, such that when an undesirable signal is present in the substantially planar transmission line, a resultant force is created, causing the substantially arc-shaped strip to flex toward the transmission line, physically and electrically contacting the transmission line and thus diverting the undesirable signal by passing the signal through the substantially arc-shaped strip to the at least one metallization contact.

Dependencies are inferred from the claim text.