Coupled transmission line resonate RF filter
The present invention includes a method of creating electrical air gap low loss low cost RF mechanically and thermally stabilized interdigitated resonate filter in photo definable glass ceramic substrate. Where a ground plane may be used to adjacent to or below the RF filter in order to prevent parasitic electronic signals, RF signals, differential voltage build up and floating grounds from disrupting and degrading the performance of isolated electronic devices by the fabrication of electrical isolation and ground plane structures on a photo-definable glass substrate.
1. A method of making a mechanically stabilized RF coupled interdigitated resonate device comprising:
masking a design layout comprising one or more structures to form one or more interdigitated structures comprising one or more electrically conductive interdigitated transmission lines, on a photosensitive glass substrate;
exposing at least one portion of the photosensitive glass substrate to an activating energy source;
heating the photosensitive glass substrate for at least ten minutes above a glass transition temperature thereof;
cooling the photosensitive glass substrate to transform at least part of the exposed glass to a crystalline material to form a glass-crystalline substrate;
etching the glass-crystalline substrate with an etchant solution to form a mechanical support device; and
coating the one or more interdigitated structures, a ground plane, an input channel and an output channel with one or more metals, wherein the one or more metals are connected to a circuitry.
2. The method of claim 1 , further comprising covering all or part of an external electrical isolation structure of the device with a metal or metallic media lid; and grounding the metal or metallic media lid.
3. The method of claim 1 , wherein one or more interdigitated structures have a mechanical and thermal stabilization structure with a contact area with the one or more interdigitated structures that is less than 50%, 40%, 35%, 30%, 25%, 20%, 10%, 5% or 1% of a contact area of the one or more interdigitated structures.
4. The method of claim 1 , wherein the coating the one or more interdigitated structures forms the one or more electrical conductive interdigitated transmission lines.
5. The method of claim 1 , wherein the one or more electrical conductive interdigitated transmission lines are an interdigitated bandpass resonate filter, a low pass resonate filter, a high pass resonate filter, ora notch resonate filter.
6. The method of claim 5 , wherein a metal line on the interdigitated bandpass resonate filter comprises titanium, titanium-tungsten, chrome, copper, nickel, gold, palladium or silver.
7. The method of claim 1 , wherein the step of etching forms an air gap between the photosensitive glass substrate and the one or more interdigitated structures.
8. The method of claim 1 , further comprising converting the glass-crystalline substrate adjacent to the one or more interdigitated structures to a ceramic phase.
9. The method of claim 1 , wherein the one or more metals are selected from Fe, Cu, Au, Ni, In, Ag, Pt, or Pd.
10. The method of claim 1 , wherein the one or more metals are connected to the circuitry through a surface, a buried contact, a blind via, a glass via, a straight line contact, a rectangular contact, a polygonal contact, or a circular contact.
11. The method of claim 1 , wherein the photosensitive glass substrate comprises a composition of: 60-76 weight % silica; at least 3 weight % K 2 O with 6 weight % - 16 weight % of a combination of K 2 O and Na 2 O; 0.003-1 weight % of at least one oxide selected from the group consisting of Ag 2 O and Au 2 O; 0.003-2 weight % Cu 2 O; 0.75 weight % - 7 weight % B 2 O 3 , and 6-7 weight % Al 2 O 3 ; with the combination of B 2 O 3 ; and Al 2 O 3 not exceeding 13 weight %; 8-15 weight % Li 2 O; and 0.001-0.1 weight % CeO 2 .
12. The method of claim 1 , wherein the photosensitive glass substrate comprises a composition of: 35-76 weight % silica, 3-16 weight % K 2 O, 0.003-1 weight % Ag 2 O, 8-15 weight % Li 2 O, and 0.001-0.1 weight % CeO 2 .
13. The method of claim 1 , wherein the photosensitive glass substrate is at least one of: a photo-definable glass substrate that comprises at least 0.1 weight % Sb 2 O 3 or As 2 O 3 ; a photo-definable glass substrate that comprises 0.003-1 weight % Au 2 O; or a photo-definable glass substrate that comprises 1-18 weight % of an oxide selected from the group consisting of CaO, ZnO, PbO, MgO, SrO and BaO; and wherein the photosensitive glass substrate has an anisotropic-etch ratio of the at least one portion that is exposed to an activating energy source to an unexposed portion that is at least one of 10-20:1; 21-29:1; 30-45:1; 20-40:1; 41-45:1; and 30-50:1.
14. The method of claim 1 , wherein the photosensitive glass substrate comprises at least one of silica, lithium oxide, aluminum oxide, or cerium oxide.
15. The method of claim 1 , wherein an RF transmission has a loss of less than 50, 40, 30, 25, 20, 15, or 10% of a signal input versus a signal output.
16. A mechanically stabilized RF coupled interdigitated resonate device made by a method comprising:
masking a design layout comprising one or more structures to form one or more interdigitated structures comprising one or more electrically conductive interdigitated transmission lines, on a photosensitive glass substrate;
exposing at least one portion of the photosensitive glass substrate to an activating energy source;
heating the photosensitive glass substrate for at least ten minutes above a glass transition temperature thereof;
cooling the photosensitive glass substrate to transform at least part of the exposed glass to a crystalline material to form a glass-crystalline substrate;
etching the glass-crystalline substrate with an etchant solution to form a mechanical support device;
coating the one or more interdigitated structures, a ground plane, an input channel and an output channel with one or more metals; and
coating all or part of the one or more electrical conductive interdigitated transmission lines with a metallic media, wherein the metallic media connected to a circuitry.
17. The device of claim 16 , wherein the one or more metals are selected from Fe, Cu, Au, Ni, In, Ag, Pt, or Pd.
18. The device of claim 16 , wherein the method for making the device further comprises covering all or part of an electrical isolation structure of the device with a metal or metallic media lid; and grounding the metal or metallic media.
19. The device of claim 16 , wherein one or more interdigitated structures have a mechanical and thermal stabilization structure with a contact area with the one or more interdigitated structures that is less than 50%, 40%, 35%, 30%, 25%, 20%, 10%, 5% or 1% of the contact area of the one or more interdigitated structures.
20. The device of claim 16 , wherein the coating the one or more interdigitated structures forms the one or more electrical conductive interdigitated transmission lines.
21. The device of claim 16 , wherein the one or more electrical conductive interdigitated transmission lines are an interdigitated resonate bandpass filter, an interdigitated resonate low pass filter, an interdigitated resonate high pass filter, or an interdigitated resonate notch filter.
22. The device of claim 21 , wherein a metal line on the interdigitated resonate bandpass filter comprises titanium, titanium-tungsten, chrome, copper, nickel, gold, palladium or silver.
23. The device of claim 16 , wherein the step of etching forms an air gap between the photosensitive glass substrate and the one or more interdigitated structures.
24. The device of claim 16 , further comprising converting the glass-crystalline substrate adjacent to the one or more interdigitated structures to a ceramic phase.