Wire-bond transmission line RC circuit
Disclosed are apparatus and associated methodology providing for fixed components that exhibit tailorable variations in frequency response depending on the applied frequencies over the component's useful frequency range. The presently disclosed subject matter provides improved operational characteristics of generally known transmission line capacitor devices by providing a parallel resistive component constructed as a portion of the dielectric separating electrodes corresponding to a capacitor.
1. An RC circuit component for insertion in a transmission line, comprising:
a monolithic substrate having a top surface;
a capacitor supported on the substrate top surface and having first and second electrodes separated at least in part by a dielectric layer; and
a thin-film resistor, wherein at least a portion of the thin-film resistor is stacked between the first and second electrodes in a vertical direction that is perpendicular to the top surface of the monolithic substrate, the thin-film resistor connected in parallel with the capacitor;
wherein the portion of the thin-film resistor that is stacked between the first and second electrodes has a resistance between the first and second electrodes of about 2 ohms or greater.
2. The RC circuit component of claim 1 , wherein:
the monolithic substrate has opposing first and second longitudinal ends; and
the component further comprises a pair of wire bond pads supported on the substrate top surface respectively at the first and second longitudinal ends thereof, and with the wire bond pads coupled respectively with the first and second electrodes of the capacitor.
3. The RC circuit component of claim 1 , wherein the thin-film resistor comprises a layer of resistive material that is trimmed to provide the resistance of the thin-film resistor.
4. The RC circuit component of claim 1 , wherein the thin-film resistor comprises a layer of resistive material that comprises ruthenium oxide (RuO 2 ).
5. The RC circuit component of claim 1 , wherein the thin-film resistor comprises a layer of resistive material that comprises at least one of tantalum nitride (TaN) or nickel-chromium alloys (NiCr).
6. The RC circuit component of claim 1 , wherein the thin-film resistor comprises a layer of resistive material that has a sheet resistance up to about 100Ω.
7. The RC circuit component of claim 1 , wherein the substrate comprises at least one of fused silica or quartz.
8. The RC circuit component of claim 1 , wherein the substrate comprises at least one of alumina or glass.
9. The RC circuit component of claim 1 , wherein:
the monolithic substrate has a bottom surface; and
the component further comprises a ground electrode received on the substrate bottom surface.
10. The RC circuit component of claim 1 , wherein the dielectric layer comprises silicon oxynitride (SiON).
11. The RC circuit component of claim 1 , wherein the dielectric layer comprises barium titanate (BaTiO 3 ).
12. The RC circuit component of claim 1 , wherein the monolithic substrate has a generally planar bottom surface and opposing generally planar first and second longitudinal ends.
13. The RC circuit component of claim 12 , wherein the RC circuit component comprises:
a pair of wire bond pads supported on the substrate top surface respectively at the generally planar first and second longitudinal ends thereof, the pair of wire bond pads respectively coupled with the first and second electrodes of the capacitor; and
a ground electrode received on the generally planar bottom surface of the substrate.
14. An RC circuit component for insertion in a transmission line, comprising:
a monolithic substrate having a top surface;
a capacitor supported on the substrate top surface and having first and second electrodes separated at least in part by a dielectric layer; and
a thin-film resistor, wherein at least a portion of the thin-film resistor is stacked between the first and second electrodes in a vertical direction that is perpendicular to the top surface of the monolithic substrate and connected in parallel with the capacitor;
wherein the thin-film resistor has a resistive value between the first and second electrodes that is selected to provide a forward transmission coefficient, S 21 , of the RC circuit component that is greater than −1.9 dB at 100 MHz.
15. The RC circuit component of claim 14 , wherein the forward transmission coefficient, S 21 , of the RC circuit component is greater than −1.9 dB for frequencies ranging from 100 MHz to 30,000 MHz.
16. The RC circuit component of claim 14 , wherein the thin-film resistor comprises a layer of resistive material that is trimmed to provide the resistance of the thin-film resistor.
17. The RC circuit component of claim 14 , wherein the thin-film resistor comprises a layer of resistive material that comprises ruthenium oxide (RuO 2 ).
18. The RC circuit component of claim 14 , wherein the thin-film resistor comprises a layer of resistive material that comprises at least one of tantalum nitride (TaN) or nickel-chromium alloys (NiCr).
19. The RC circuit component of claim 14 , wherein the thin-film resistor comprises a layer of resistive material that has a sheet resistance up to about 100Ω.
20. The RC circuit component of claim 14 , wherein the substrate comprises at least one of fused silica or quartz.
21. The RC circuit component of claim 14 , wherein the substrate comprises at least one of alumina or glass.
22. The RC circuit component of claim 14 , wherein:
the monolithic substrate has a bottom surface; and
the component further comprises a ground electrode received on the substrate bottom surface.
23. The RC circuit component of claim 14 , wherein the dielectric layer comprises silicon oxynitride (SiON).
24. The RC circuit component of claim 14 , wherein the dielectric layer comprises barium titanate (BaTiO 3 ).
25. The RC circuit component of claim 14 , wherein the RC circuit component comprises:
a pair of wire bond pads supported on the substrate top surface respectively at generally planar first and second longitudinal ends thereof, the pair of wire bond pads respectively coupled with the first and second electrodes of the capacitor; and
a ground electrode received on a generally planar bottom surface of the substrate.
26. A method for tailoring the frequency response of an RC circuit component for insertion in a transmission line, the circuit component comprising a monolithic substrate having a top surface, a capacitor supported on the top surface of the substrate and having at least partially overlapping first and second electrodes separated at least in part by a dielectric layer, the method comprising:
providing a thin-film resistor stacked at least in part between the first and second electrodes in a vertical direction that is perpendicular to the top surface of the monolithic substrate, the thin-film resistor connected in parallel with the capacitor; and
trimming a resistive layer of the thin-film resistor to provide a desired resistance of the thin-film resistor that is about 2 ohms or greater between the first and second electrodes.