Low noise amplifiers including group III nitride based high electron mobility transistors

1. A monolithic microwave integrated circuit comprising:

a substrate; and

a low noise amplifier on the substrate and comprising:

an input port on the substrate for receiving an input signal to be amplified;

a first Group III-nitride based transistor on the substrate and having a gate coupled to the input port, wherein the first Group III-nitride based transistor is configured to provide a first stage of amplification to the input signal;

a second Group III-nitride based transistor on the substrate and having a gate coupled to a drain of the first Group III-nitride based transistor, wherein the second Group III-nitride based transistor is configured to provide a second stage of amplification to the input signal; and

an output port on the substrate and coupled to a drain of the second Group III-nitride based transistor, wherein at least one of the first and second Group III-nitride based transistors comprises at least two field plates.

2. The monolithic microwave integrated circuit of claim 1 , wherein the first and second Group III-nitride based transistors comprise Group III-nitride based high electron mobility transistors.

3. A monolithic microwave integrated circuit amplifier comprising:

a substrate;

an input port on the substrate for receiving an input signal to be amplified;

a first Group III-nitride based transistor on the substrate and having a gate coupled to the input port, wherein the first Group III-nitride based transistor is configured to provide a first stage of amplification to the input signal;

a second Group III-nitride based transistor on the substrate and having a gate coupled to a drain of the first Group III-nitride based transistor, wherein the second Group III-nitride based transistor is configured to provide a second stage of amplification to the input signal; and

an output port on the substrate and coupled to a drain of the second Group III-nitride based transistor, wherein at least one of the first and second Group III-nitride based transistors comprises a field plate conductively connected to a source terminal of the at least one transistor.

4. The monolithic microwave integrated circuit amplifier of claim 3 , wherein the field plate comprises a first field plate, the at least one transistor further comprising a second field plate that is electrically isolated from the first field plate.

5. The monolithic microwave integrated circuit amplifier of claim 4 , wherein the second field plate is conductively connected to a source terminal of the at least one transistor.

6. The monolithic microwave integrated circuit of claim 1 , further comprising an input network coupled between the input port and the first Group III-nitride based transistor, an interstage network coupled between the first Group III-nitride based transistor and the second Group III-nitride based transistor, and an output network coupled between the second Group III-nitride based transistor and the output port.

7. The monolithic microwave integrated circuit of claim 1 , further comprising a first gate bias port coupled to a gate of the first Group III-nitride based transistor, a first drain bias port coupled to a drain of the first Group III-nitride based transistor, a second gate bias port coupled to a gate of the second Group III-nitride based transistor, and a second drain bias port coupled to a drain of the second Group III-nitride based transistor.

8. The monolithic microwave integrated circuit of claim 1 , wherein the first Group III-nitride transistor has a gate periphery less than about 1 mm, and the second Group III-nitride transistor has a gate periphery greater than about 1 mm.

9. The monolithic microwave integrated circuit of claim 8 , wherein the first Group III-nitride transistor has a gate periphery of about 0.72 mm, and the second Group III-nitride transistor has a gate periphery of about 1.2 mm.

10. A package comprising a monolithic microwave integrated circuit as recited in claim 1 , wherein the package has a footprint not greater than 0.5 inches square.

11. The monolithic microwave integrated circuit of claim 1 configured to provide a third order intercept greater than 25 dBm at a frequency that is in the range of 2.6 GHz to 3.95 GHz.

12. The monolithic microwave integrated circuit of claim 1 configured to provide a noise figure less than 3.0 dB at a frequency that is in the range of 2.6 GHz to 3.95 GHz.

13. The monolithic microwave integrated circuit of claim 1 , wherein at least one of the at least two field plates is conductively connected to a source terminal of the at least one transistor.

14. The monolithic microwave integrated circuit of claim 1 , wherein at least one of the at least two field plates is conductively connected to a gate terminal of the at least one transistor.

15. The monolithic microwave integrated circuit of claim 1 , wherein the at least two field plates comprise a first field plate and a second field plate that is electrically isolated from the first field plate.

16. The monolithic microwave integrated circuit of claim 15 , wherein the second field plate is conductively connected to a source terminal of the at least one transistor.

17. The monolithic microwave integrated circuit amplifier of claim 3 , configured to operate as a low noise amplifier.

18. The monolithic microwave integrated circuit of claim 1 , wherein at least one of the at least two field plates is integral with the gate of the at least one of the first and second Group III-nitride based transistors.

19. The monolithic microwave integrated circuit of claim 4 , wherein at least one of the first and second field plates is integral with the gate of the at least one of the first and second Group III-nitride based transistors.