US 6,440,767 B1Granted

Monolithic single pole double throw RF MEMS switch

AssigneeHRL Laboratories, LLC

InventorsRobert Y. Loo, James H. Schaffner, Adele E. Schmitz, Tsung-Yuan Hsu, Franklin A. Dolezal, Gregory L. Tangonan

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Abstract

Apparatus for a micro-electro-mechanical switch that provides single pole, double throw switching action. The switch comprises a single RF input line and two RF output lines. The switch additionally comprises two armatures, each mechanically connected to a substrate at one end and having a conducting transmission line at the other end with a suspended biasing electrode located on top of or within a structural layer of the armature. Each conducting transmission line has conducting dimples that protrude beyond the bottom of the armature carrying the conducting transmission line. Closure of an armature causes the dimples of the corresponding conducting transmission line to mechanically and electrically engage the RF input line and the corresponding RF output line, thus directing RF energy from the RF input line to the selected RF output line.

Claims20

Dependent claims

A method of switching an RF signal applied at an input port to one of two output ports, comprising the steps of:

providing a monolithic SPDT RF MEMS switch comprising:
a substrate;
an input line on top of the substrate;
a first output line on top of the substrate and separated from the input line;
a first substrate electrode on top of the substrate, located adjacent to but separated from the input line and the first output line;
a second output line on top of the substrate and separated from the input line;
a second substrate electrode on top of the substrate, located adjacent to but separated from the input line and the second output line;
a first armature comprising:
a first armature lower structural layer having a first end mechanically connected to the substrate and a second end positioned over the input line and first output line;
a first conducting transmission line located at the second end of the first armature structural layer and suspended above the input line and the first output line;
and
a first suspended armature electrode disposed above and in contact with the first armature lower structural layer and suspended above the first substrate electrode;
and
a second armature comprising:
a second armature lower structural layer having a first end mechanically connected to the substrate and a second end positioned over the input line and the second output line;
a second conducting transmission line located at the second end of the second armature structural layer and suspended above the input line and the second output line;
and
a second suspended armature electrode disposed above and in contact with the second armature lower structural layer and suspended above the second substrate electrode;
and
connecting the input port to the input line;
connecting one of the output ports to the first output line and the other output port to the second output line;
and
applying a voltage between a selected one of the two substrate electrodes and the armature electrode suspended above the substrate electrode so as to cause the armature suspended above the selected substrate electrode to close.

20 more elements

A micro-electro-mechanical switch, comprising

a) a substrate;
b) an input line on top of the substrate;
c) a first output line on top of the substrate and separated from the input line;
d) a first substrate electrode on top of the substrate, located adjacent to but separated from the input line and the first output line;
e) a second output line on top of the substrate and separated from the input line;
f) a second substrate electrode on top of the substrate, located adjacent to but separated from the input line and the second output line;
g) a first armature comprising:
1) a first armature lower structural layer having a first end mechanically connected to the substrate and a second end positioned over the input line and first output line;
2) a first conducting transmission line located at the second end of the first armature structural layer and suspended above the input line and the first output line;
and
3) a first suspended armature electrode disposed above and in contact with the first armature lower structural layer and suspended above the first substrate electrode;
and
h) a second armature comprising:
1) a second armature lower structural layer having a first end mechanically connected to the substrate and a second end positioned over the input line and the second output line;
2) a second conducting transmission line located at the second end of the second armature structural layer and suspended above the input line and the second output line;
and
3) a second suspended armature electrode disposed above and in contact with the second armature lower structural layer and suspended above the second substrate electrode.

14 more elements

Dependencies are inferred from the claim text.