Broadside-coupled transformers with improved bandwidth
View Patent ↗A monolithic microwave integrated circuit (MMIC) compatible broadside-coupled transformer including (i) a first transmission line, (ii) a second transmission line, and (iii) a third transmission line. The first and the second transmission lines generally form the broadside-coupled transformer. The third transmission line is generally connected in series with the broadside-coupled transmission line forming a ground return path of the broadside-coupled transformer.
1. A monolithic microwave integrated circuit (MMIC) compatible broadside-coupled transformer comprising:
a first transmission line;
a second transmission line; and
a third transmission line, wherein the first and the second transmission lines form the broadside-coupled transformer and said third transmission line (i) is connected in series with the broadside-coupled transmission line forming a ground return path of the broadside-coupled transformer and (ii) has an electrical length of about one quarter wavelength at the half-wavelength freguency of the broadside-coupled transmission line forming the ground return path of the broadside-coupled transformer.
2. The monolithic microwave integrated circuit (MMIC) compatible transformer according to claim 1 , wherein said third transmission line is configured to reduce a half-wavelength resonance of the broadside-coupled transmission line forming the ground return path of the broadside-coupled transformer.
3. The monolithic microwave integrated circuit (MMIC) compatible transformer according to claim 1 , wherein said third transmission line is outside the broadside-coupled structure formed by the first and the second transmission lines.
4. The monolithic microwave integrated circuit (MMIC) compatible transformer according to claim 1 , wherein said first and said second transmission lines are separated by a controlled dielectric thickness.
5. The monolithic microwave integrated circuit (MMIC) compatible transformer according to claim 1 , wherein said MMIC implements a device selected from the group consisting of a low noise amplifier, power amplifier, phase shifter and attenuatator.
6. The monolithic microwave integrated circuit (MMIC) compatible transformer according to claim 1 , wherein said MMIC compatible transformer impedance matches one or more active devices in said MMIC.
7. The monolithic microwave integrated circuit (MMIC) compatible transformer according to claim 1 , wherein said third transmission line physically separates a radio frequency (RF) input of said transformer from an RF output of said transformer.
8. The monolithic microwave integrated circuit (MMIC) compatible transformer according to claim 1 , wherein said third transmission line has a physical length ranging from about one-quarter to about one-half of a physical length of the broadside-coupled transformer.
9. The monolithic microwave integrated circuit (MMIC) compatible transformer according to claim 1 , wherein said first and said second transmission lines are separated by a dielectric.
10. The monolithic microwave integrated circuit (MMIC) compatible transformer according to claim 9 , wherein said dielectric comprises at least one of benzocyclobutene or polyimide.
11. A method of reducing a half-wavelength resonance of a broadside-coupled transformer comprising:
forming a first transmission line on a substrate;
depositing a dielectric layer;
forming a second transmission line on said dielectric layer; and
forming a third transmission line, wherein the first and the second transmission lines form the broadside-coupled transformer and said third transmission line (i) is connected in polyimide. series with the broadside-coupled transmission line forming a ground return path of the broadside-coupled transformer and (ii) has an electrical length of about one quarter wavelength at the half-wavelength frequency of the broadside-coupled line forming the ground return path of the broadside-coupled transformer.
12. The method according to claim 11 , wherein said third transmission line is configured to reduce a half-wavelength resonance of the broadside-coupled transmission line forming the ground return path of the broadside-coupled transformer.
13. The method according to claim 11 , wherein said third transmission line is disposed outside the broadside-coupled structure formed by the first and the second transmission lines.
14. The method according to claim 11 , wherein said first and said second transmission lines are separated by a controlled dielectric thickness.
15. The method according to claim 11 , wherein said dielectric layer comprises at least one of benzocyclobutene or polyimide.
16. The method according to claim 11 , wherein said third transmission line physically separates a radio frequency (RF) input of said transformer from an RF output of said transformer.
17. The method according to claim 11 , wherein said third transmission line has a physical length ranging from about one-quarter to about one-half of a physical length of the broadside-coupled transformer.
18. The method according to claim 11 , wherein said broadside-coupled transformer is part of a monolithic microwave integrated circuit (MMIC).
19. The method according to claim 18 , wherein said MMIC implements a device selected from the group consisting of a low noise amplifier, power amplifier, phase shifter and attenuatator.
20. The method according to claim 18 , wherein said MMIC compatible transformer impedance matches one or more active devices in said MMIC.