High-power amplifier package
Package assemblies for improving heat dissipation of high-power components in microwave circuits are described. A laminate that includes microwave circuitry may have cut-outs that allow high-power components to be mounted directly on a heat slug below the laminate. Electrical connections to circuitry on the laminate may be made with wire bonds. The packaging allows more flexible design and tuning of packaged microwave circuitry.
1. A high-power microwave circuit assembled in a package comprising:
a microwave circuit formed on a laminate;
a case supporting conductive leads that are connected to the microwave circuit;
a heat slug connected to the case and extending from an interior region of the case to an exterior region of the case;
a cut-out in the laminate; and
a first power transistor mounted directly on the heat slug within the cut-out of the laminate and connected to the microwave circuit.
2. The high-power microwave circuit of claim 1 , wherein the first power transistor is capable of outputting power levels between 50 W and 100 W at duty cycles greater than 50% without significant degradation of the amplifier's performance.
3. The high-power microwave circuit of claim 1 , wherein the first power transistor is capable of outputting power levels between 100 W and 200 W at duty cycles greater than 50% without significant degradation of the amplifier's performance.
4. The high-power microwave circuit of claim 3 , wherein the first power transistor comprises GaN.
5. The high-power microwave circuit of claim 4 , further comprising a second power transistor mounted directly on the heat slug in a second cut-out in the laminate and having an output connected to an input of the first power transistor.
6. The high-power microwave circuit of claim 4 , further comprising a second power transistor mounted directly on the heat slug in a second cut-out in the laminate and connected in parallel with the first power transistor in a Doherty configuration.
7. The high-power microwave circuit of claim 3 , wherein the package complies with specifications for a standardized package.
8. The high-power microwave circuit of claim 7 , wherein the microwave circuit comprises conductive interconnects, at least one resistor, and at least three capacitors.
9. The high-power microwave circuit of claim 1 , wherein the laminate is mounted directly on the heat slug.
10. The high-power microwave circuit of claim 9 further comprising first wire bonds connecting terminals of the first power transistor to the microwave circuit.
11. The high-power microwave circuit of claim 10 , wherein there is more than one wire bond connecting in parallel one terminal of the first power transistor to the microwave circuit.
12. The high-power microwave circuit of claim 10 , further comprising second wire bonds that connect the conductive leads to the microwave circuit, wherein the second wire bonds are of the same diameter as the first wire bonds and connected in the same way as the first wire bonds.
13. The high-power microwave circuit of claim 9 , wherein a height differential between bonding pads on the first power transistor and conductive interconnects on the microwave circuit is between approximately 5 mils and approximately 20 mils.
14. The high-power microwave circuit of claim 1 , further comprising a capacitor having a breakdown voltage between 200V and 500V mounted on the laminate.
15. The high-power microwave circuit of claim 1 , further comprising an inductor patterned in the laminate.