Broadband integrated RF/microwave/millimeter mixer with integrated balun(s)
A broadband radio frequency, microwave, or millimeter mixer system may include a balun and a mixer. The balun may have an unbalanced port; a balanced port; a first and a second inductor tightly and inversely magnetically coupled to one another; and a third inductor which is not magnetically coupled to the first or the second inductors. The mixer may be connected to the balanced port of the balun. The balun, including its three inductors, and the mixer may all be integrated onto a single substrate that forms an integrated circuit.
1. A broadband radio frequency, microwave, or millimeter mixer system comprising:
a balun that has:
an unbalanced port;
a balanced port;
a first and a second inductor tightly and inversely magnetically coupled to one another; and
a third inductor which is not magnetically coupled to the first or the second inductors; and
a mixer connected to the balanced port of the balun,
wherein the balun, including its three inductors, and the mixer are all integrated onto a single substrate that forms an integrated circuit.
2. The mixer system of claim 1 wherein two of the inductors are connected in series.
3. The mixer system of claim 2 wherein the first and the third inductor are connected in series.
4. The mixer system of claim 2 wherein one of the inductors is not electrically connected to the other two.
5. The mixer system of claim 1 wherein the unbalanced port is an input to the mixer.
6. The mixer system of claim 5 wherein the mixer functions as an up converter.
7. The mixer system of claim 5 wherein the mixer functions as a down converter.
8. The mixer system of claim 1 wherein the unbalanced port is an output from the mixer.
9. The mixer system of claim 8 wherein the mixer functions as an up converter.
10. The mixer system of claim 8 wherein the mixer functions as a down converter.
11. The mixer system of claim 1 further comprising a second balun.
12. The mixer system of claim 11 further comprising a third balun.
13. The mixer system of claim 1 further comprising a capacitance in series with one of the inductors.
14. The mixer system of claim 1 further comprising a capacitance that DC isolates the third inductor from ground.
15. The mixer system of claim 1 wherein the mixer is an active mixer.
16. The mixer system of claim 1 wherein the mixer is a passive mixer.
17. The mixer system of claim 1 further comprising an amplifier between the balun and the mixer.
18. The mixer system of claim 17 wherein the amplifier is a differential amplifier.
19. The mixer system of claim 1 wherein all of the three inductors lie in the same plane.
20. The mixer system of claim 1 wherein two of the three inductors lie in a different plane.