Electronic circuits including a MOSFET and a dual-gate JFET
Electronic circuits and methods are provided for various applications including signal amplification. An exemplary electronic circuit comprises a MOSFET and a dual-gate JFET in a cascode configuration. The dual-gate JFET includes top and bottom gates disposed above and below the channel. The top gate of the JFET is controlled by a signal that is dependent upon the signal controlling the gate of the MOSFET. The control of the bottom gate of the JFET can be dependent or independent of the control of the top gate. The MOSFET and JFET can be implemented as separate components on the same substrate with different dimensions such as gate widths.
1. An electronic circuit comprising:
a MOSFET including a source, a drain, and a gate;
a JFET, distinct from the MOSFET, and including a source, a drain, a top gate, and a bottom gate, the source of the JFET being directly coupled to the drain of the MOSFET; and
a common node circuit coupled between ground and a common node between the drain of the MOSFET and the source of the JFET.
2. The electronic circuit of claim 1 wherein the top and bottom gates of the JFET are both coupled to ground.
3. The electronic circuit of claim 1 wherein the gates of the MOSFET and of the JFET have different widths.
4. An electronic circuit comprising:
a MOSFET including a source, a drain, and a gate; and
a JFET, distinct from the MOSFET, and including a source, a drain, a top gate coupled to the gate of the MOSFET, and a bottom gate,
the source of the JFET being directly coupled to the drain of the MOSFET.
5. The electronic circuit of claim 4 wherein the bottom gate of the JFET is coupled to the gate of the MOSFET.
6. The electronic circuit of claim 5 wherein the top and bottom gates of the JFET are both coupled to a DC bias source.
7. The electronic circuit of claim 4 wherein the gates of the MOSFET and of the JFET have different widths.
8. An electronic circuit comprising:
a MOSFET including a source, a drain, and a gate; and
a JFET, distinct from the MOSFET, and including a source, a drain, a top gate, and a bottom gate,
the source of the JFET being directly coupled to the drain of the MOSFET, the top gate of the JFET being coupled to the bottom gate of the JFET, and both gates being independent of the gate of the MOSFET.
9. The electronic circuit of claim 8 wherein the top and bottom gates of the JFET are both coupled to a DC bias source.
10. The electronic circuit of claim 8 wherein the top and bottom gates of the JFET are both coupled to ground.
11. The electronic circuit of claim 8 wherein the top gate of the JFET is coupled to a first DC bias source and the bottom gate of the JFET is coupled to a second DC bias source.
12. The electronic circuit of claim 8 wherein the gates of the MOSFET and of the JFET have different widths.
13. An electronic circuit comprising:
a MOSFET including a source, a drain, and a gate; and
a JFET, distinct from the MOSFET, and including a source, a drain, a top gate, and a bottom gate,
the source of the JFET being directly coupled to the drain of the MOSFET, the top gate of the JFET being coupled to the gate of the MOSFET, and the bottom gate of the JFET being independent of the gate of the MOSFET.
14. The electronic circuit of claim 13 wherein the top gate of the JFET is coupled to a DC bias source.
15. The electronic circuit of claim 13 wherein the bottom gate of the JFET is coupled to a DC bias source.
16. The electronic circuit of claim 13 wherein the bottom gate of the JFET is coupled to ground.
17. The electronic circuit of claim 13 wherein the gates of the MOSFET and of the JFET have different widths.
18. A method comprising:
controlling a gate of a MOSFET with a first signal;
controlling a top gate of a JFET with a second signal, the JFET being in a cascode configuration with the MOSFET; and
controlling a bottom gate of the JFET with a third signal.
19. The method of claim 18 wherein the second signal is dependent on the first signal.
20. The method of claim 19 wherein the third signal is dependent on the second signal.
21. The method of claim 18 wherein the second signal is independent on the first signal.
22. The method of claim 21 wherein the third signal is dependent on the second signal.