Form C relay and package using same
View Patent ↗The improved reed relay package provided a “pseudo” Form C relay that includes two Form A relays with at least one bridge filter element electrically interconnecting the signal outputs thereof to reduce stub capacitance and improve RF performance. As a result, the reed relay package can operate at very high frequencies, such as 18 GHz and higher. Also, vias can be provided through the support substrate to simulate a co-planar waveguide and RF shields profiled with cut-outs to better simulate a 50 ohm impedance environment throughout the path of the signal line.
1. A reed relay device, comprising:
a support substrate having a first side and a second side;
a first reed switch having a main body with signal input and a signal output;
a second reed switch having a main body with a signal input and a signal output;
a first ground shield surrounding the main body of the first reed switch;
a second ground shield surrounding the main body of the second reed switch;
a plurality of ground terminals on the first side of the support substrate connected to the first ground shield;
a plurality of ground terminals on the first side of the support substrate connected to the second ground shield;
a first signal via routed through the substrate and interconnected to the signal output of the first reed switch;
a second signal via routed through the substrate and interconnected to the signal output of the second reed switch;
a first plurality of ground vias routed through the substrate and interconnected to the first ground shield;
a second plurality of ground vias routed through the substrate and interconnected to the second ground shield;
a plurality of contacts on the second side of the support substrate respectively electrically interconnected to the first signal via, the second signal via, the first plurality of ground vias and the second plurality of ground vias; and
at least one filter element electrically bridging the signal output of the first reed switch with the signal output of the second reed switch.
2. The reed device package of claim 1 , wherein the support substrate has a plurality of seats for respectively receiving the first reed switch and the second reed switch.
3. The reed device package of claim 1 , wherein the plurality of contacts are solder balls.
4. The reed device package of claim 2 , wherein the first ground shield and the second ground shield are profiled to compensate for differences in capacitance at the point in the transmission line where the respective glass seals of the first reed switch and the second reed switch are positioned to reduce impedance discontinuities at those two locations.
5. A reed relay device, comprising:
a first reed switch with signal input and a signal output;
a second reed switch with a signal input and a signal output;
at least one low pass filter element electrically bridging the signal output of the first reed switch with the signal output of the second reed switch;
whereby stub capacitance is reduced and RF performance is improved.