Metamaterial Substrate For Circuit Design
20170033468 ยท 2017-02-02
Inventors
Cpc classification
H01L2924/19105
ELECTRICITY
H01L2223/6677
ELECTRICITY
H01Q19/005
ELECTRICITY
H01L2224/16227
ELECTRICITY
H01Q15/0086
ELECTRICITY
H01P1/2005
ELECTRICITY
International classification
H01Q15/00
ELECTRICITY
H01Q19/00
ELECTRICITY
Abstract
This invention enables Frequency Selective Surface (FSS) and Artificial Magnetic Conductor (AMC) which exhibits Electromagnetic Band Gap (EBG) in any of the substrate's layer from a small and thin systems and sub-systems in package to a large-format PCBs. The metamaterial substrate may be integrated with electronic circuit components or buried in PCBs for circuit designs capable of transmitting, receiving and reflecting electromagnetic energy, altering electromagnetic properties of natural circuit materials, enhancing electrical characteristics of electrical components (such as filters, antennas, baluns, power dividers, transmission lines, amplifiers, power regulators, and printed circuits elements) in systems and sub-systems circuit designs. The metamaterial substrate creates new electrical characteristics, properties and systems, sub-systems or component's specification not readily available with conventional circuit materials, substrates, and PCBs. The metamaterial substrate can be less than 70 m thick and buried into any PCB layer.
Claims
1. An apparatus comprising a substantially small sized and thinner electromagnetic band gap structure for a predetermined band gap frequency band, said apparatus comprising: a. coplanar conductive unit elements that are periodically arrayed with an edge to edge spacing d between each of the adjacent said coplanar conductive unit elements forming a first layer, b. a dielectric having a thickness h.sub.r and a relative dielectric permittivity .sub.r forming a second layer, c. a contiguous conductive plane forming a third layer, d. a capacitive surface means arranged in part by the length of the outer perimeter of each of said coplanar conductive unit elements, in part by the spacing d between each of the adjacent said coplanar conductive unit elements and in part by said relative dielectric permittivity .sub.r of said dielectric for enabling a substantially increased distributed capacitance being electrically coupled in series between each of the adjacent said coplanar conductive unit elements in the array on said first layer, e. an inductive connection means arranged beside said capacitive surface means for enabling a substantially increased distributed inductance being electrically coupled in shunt between each of said coplanar conductive unit elements in the array on said first layer and said contiguous conductive plane on said third layer and with said dielectric therein, f. a composite reference plane comprised of said first layer, second layer and third layer to form a sufficient resonance circuit with said predetermined band gap frequency band by said capacitive surface means and said inductive connection means, g. a first miniature means originated from said inductive connection means for enabling a first ratio, alpha, of said thickness h.sub.r to the free space wavelength of at least one use frequency falling within said predetermined band gap frequency band, to be such that as to minimize said thickness h.sub.r while providing said sufficient resonance circuit of said composite reference plane, and h. a second miniature means originated from said capacitive surface means for enabling a second ratio, beta, of the length of at least one side of the outer perimeter of each of said coplanar conductive unit elements and a third ratio, gamma, of the spacing d respectively to at least one use frequency falling within said predetermined band gap frequency band, to be such that as to minimize the length of the outer perimeter and the spacing d while providing said sufficient resonance circuit of said composite reference plane, whereby the electromagnetic band gap structure can be made substantially thinner and smaller in dimensions which can be used to integrate with electrical circuits and microelectronic devices that have constraints in dimensions and thickness and means practical.
2. The apparatus of claim 1 further comprising a third miniature means made up with the spacing d of said second miniature means and said thickness h.sub.r of said first miniature means for establishing a fourth ratio, delta, of the spacing d to said thickness h.sub.r, said ratio delta being substantially greater than 1.
3. The apparatus of claim 1 wherein each of said coplanar conductive unit elements further comprises a coplanar contiguous conductive area inside surrounding an opening.
4. The apparatus of claim 3 wherein said opening contains at least one coplanar inductive element inside and at least one coplanar terminal electrode being centrally positioned in said opening, and wherein said coplanar contiguous conductive area and said coplanar terminal electrode are electrically connected in series by said coplanar inductive element.
5. The apparatus of claim 4 wherein said coplanar inductive element is made with at least one coplanar conductive wire structure originating from a centrally positioned origin.
6. The apparatus of claim 4 wherein said coplanar terminal electrode is electrically connected by a conductive post to said contiguous conductive plane.
7. The apparatus of claim 4 wherein said coplanar terminal electrode is a means for constituting an electrical coupling to said contiguous conductive plane through said second layer, of said dielectric, therein.
8. The apparatus of claim 1 wherein said inductive connection means comprises of an opening, at least one coplanar inductive element and at least one coplanar terminal electrode inside each of said coplanar conductive unit elements on said first layer, and wherein said coplanar inductive element is positioned inside said opening and electrically connected in series between the perimeter of said opening and said coplanar terminal electrode, and wherein said coplanar terminal electrode is centrally positioned inside said opening and is a means for constituting an electrical coupling from said coplanar inductive element to said contiguous conductive plane through said dielectric therein.
9. The apparatus of claim 8 wherein said coplanar inductive element is made with at least one coplanar conductive wire structure originating from a centrally positioned origin.
10. The apparatus of claim 8 further comprises a conductive post connected between said coplanar terminal electrode and said contiguous conductive plane.
11. The apparatus of claim 1 wherein said inductive connection means comprises of a terminal opening on said third layer inside said contiguous conductive plane so as to correspond to each of said coplanar conductive unit elements, a conductive post and a chip inductor, wherein said conductive post is arranged orthogonal and electrically connected between each of said coplanar conductive unit elements and either of terminals of said chip inductor at said terminal opening, and the other terminal of said chip inductor is connected to said contiguous conductive plane.
12. The apparatus of claim 1 wherein said first miniature means associated with said thickness h.sub.r is arranged to provide said first ratio alpha of less than 0.02.
13. The apparatus of claim 1 wherein said first miniature means associated with said thickness h.sub.r is arranged to provide said first ratio alpha of approximately from 0.001 to 0.0001.
14. The apparatus of claim 1 wherein said first miniature means associated with said thickness h.sub.r is arranged to provide said first ratio alpha of approximately 0.0002.
15. The apparatus of claim 1 wherein said second miniature means associated with the length of the outer perimeter is arranged to provide said second ratio beta of less than 0.1.
16. The apparatus of claim 1 wherein said second miniature means associated with the length of the outer perimeter is arranged to provide said second ratio beta of approximately from 0.01 to 0.02.
17. The apparatus of claim 1 wherein said second miniature means associated with the spacing d is arranged to provide said third ratio gamma of less than 0.01.
18. The apparatus of claim 1 wherein said second miniature means associated with the spacing d is arranged to provide said third ratio gamma of approximately from 0.001 to 0.004.
19. A signal transmission device comprising at least one conductor forming a first layer, a top dielectric forming a second layer, and a third layer that is a composite reference plane constituted by said apparatus according to claim 1, wherein the dielectric thickness h.sub.r of said composite reference plane of said third layer is equal or less than the dielectric thickness of said top dielectric of said second layer.
20. The signal transmission device of claim 19 wherein said conductor is a transmission line, whereby a substantially close to 50 Ohm impedance transmission line is constituted over said substantially small sized and thinner electromagnetic band gap structure which provides a means for enabling substantially lowered transmission loss, substantially lowered impedance variation and substantially lowered reflection at either terminals of said signal transmission device.
21. The signal transmission device of claim 20 further comprising an upper dielectric positioned on top of said transmission line and a contiguous conductive plane being positioned on top of said upper dielectric.
22. The signal transmission device of claim 20 further comprising an upper dielectric positioned on top of said transmission line and an upper composite reference plane being positioned on top of said upper dielectric, wherein said upper composite reference plane is a vertically flipped replication of said composite reference plane of said signal transmission device.
23. The signal transmission device of claim 19 wherein said conductor of said first layer is a transducer.
24. The signal transmission device of claim 19 wherein said conductor of said first layer is an antenna, whereby said antenna is enabled to resonate at a substantially lowered frequency band in a constrained area which is constituted by said substantially small sized and thinner electromagnetic band gap structure which provides a means to integrate with electrical circuits and microelectronic devices that have constraints in dimensions and thickness and means practical for antenna miniaturization and antenna in package devices.
25. The signal transmission device of claim 24 further comprising a magneto dielectric materials positioned on top of said antenna.
26. A 3D system-in-package device comprising at least one of said apparatus according to claim 1 as a composite reference plane.
27. The 3D system-in-package device of claim 26 wherein said 3D system-in-package device contains a device selected from the group consisting of antennas, transmission lines, transducers, glass substrates, silicon substrates, ceramic substrates, dielectric substrates, active silicon devices, passive components, filters, conductors and printed circuits.
28. A method of making a substantially small sized and thinner electromagnetic band gap structure for a predetermined band gap frequency band, comprising: a. providing an array of coplanar conductive unit elements which are periodically arrayed with an edge to edge spacing d between each of the coplanar conductive unit elements to form a first layer, b. providing a dielectric having a thickness h.sub.r and a relative dielectric permittivity .sub.r which forms a second layer, c. providing a contiguous conductive plane which forms a third layer, d. providing a capacitive surface means which is arranged in part by the length of the outer perimeter of each of the coplanar conductive unit elements, in part by the spacing d between each of the adjacent coplanar conductive unit elements and in part by said relative dielectric permittivity .sub.r of said dielectric for enabling a substantially increased distributed capacitance being electrically coupled in series between each of the adjacent coplanar conductive unit elements in the array on said first layer, e. providing an inductive connection means which is arranged beside said capacitive surface means for enabling a substantially increased distributed inductance being electrically coupled in shunt between each of the coplanar conductive unit elements in the array on said first layer and said contiguous conductive plane on said third layer and with said dielectric therein, f. providing a composite reference plane comprised of said first layer, second layer and third layer to form a sufficient resonance circuit with said predetermined band gap frequency band by said capacitive surface means and said inductive connection means, g. providing a first miniature means which is originated from said inductive connection means for enabling a first ratio, alpha, of said thickness h.sub.r to the free space wavelength of at least one use frequency falling within said predetermined band gap frequency band, to be such that as to minimize said thickness h.sub.r while providing said sufficient resonance circuit of said composite reference plane, and h. providing a second miniature means which is originated from said capacitive surface means for enabling a second ratio, beta, of the length of at least one side of the outer perimeter of each of the coplanar conductive unit elements and a third ratio, gamma, of the spacing d respectively to at least one use frequency falling within said predetermined band gap frequency band, to be such that as to minimize the length of the outer perimeter and the spacing d while providing said sufficient resonance circuit of said composite reference plane, whereby the electromagnetic band gap structure can be made substantially thinner and smaller in dimensions which can be used to integrate with electrical circuits and microelectronic devices that have constraints in dimensions and thickness and means practical.
29. The method of claim 28 wherein said inductive connection means comprises an opening, at least one coplanar inductive element and at least one coplanar terminal electrode inside each of the coplanar conductive unit elements on said first layer, and wherein said coplanar inductive element is positioned inside said opening and electrically connected in series between the perimeter of said opening and said coplanar terminal electrode, and wherein said coplanar terminal electrode is centrally positioned inside said opening and is a means for constituting an electrical coupling from said coplanar inductive element to said contiguous conductive plane through said dielectric therein.
30. The method of claim 29 wherein said coplanar inductive element is made with at least one coplanar conductive wire structure originating from a centrally positioned origin.
31. The method of claim 29 further providing a conductive post which connects said coplanar terminal electrode and said contiguous conductive plane.
32. The method of claim 28 wherein said inductive connection means comprises a terminal opening on said third layer inside of said contiguous conductive plane so as to correspond to each of the coplanar conductive unit elements, a conductive post and a chip inductor, wherein said conductive post is arranged orthogonal and electrically connected between each of the coplanar conductive unit elements and either of terminals of said chip inductor at said terminal opening, and the other terminal of said chip inductor is connected to said contiguous conductive plane.
33. The method of claim 28 wherein said first miniature means associated with said thickness h.sub.r is arranged to provide said first ratio alpha of less than 0.02.
34. The method of claim 28 wherein said first miniature means associated with said thickness h.sub.r is arranged to provide said first ratio alpha of approximately from 0.001 to 0.0001.
35. The method of claim 28 wherein said second miniature means associated with the length of the outer perimeter is arranged to provide said second ratio beta of less than 0.1.
36. The method of claim 28 wherein said second miniature means associated with the length of the outer perimeter is arranged to provide said second ratio beta of approximately from 0.01 to 0.02.
37. The method of claim 28 wherein said second miniature means associated with the spacing d is arranged to provide said third ratio gamma of less than 0.01.
38. The method of claim 28 wherein said second miniature means associated with the spacing d is arranged to provide said third ratio gamma of approximately from 0.001 to 0.004.
39. A method of making a substantially thinner and more compact signal transmission device that has at least one substantially thinner and small sized composite reference plane, wherein the composite reference plane is a three layers structure with a predetermined band gap frequency band, comprising: a. providing at least one conductor which forms a first layer, b. providing a first dielectric which has a thickness h1 and a relative dielectric permittivity .sub.1 to form a second layer, c. providing an array of coplanar conductive unit elements which are periodically arrayed with an edge to edge spacing d between each of the adjacent coplanar conductive unit elements to form a third layer, d. providing a base dielectric having a thickness h.sub.r and a relative dielectric permittivity .sub.r which forms a fourth layer, e. providing a contiguous conductive plane which forms a fifth layer, f. providing a capacitive surface means which is arranged in part by the length of the outer perimeter of each of the coplanar conductive unit elements, in part by the spacing d between each of the adjacent coplanar conductive unit elements and in part by said relative dielectric permittivity .sub.r of said base dielectric for enabling a substantially increased distributed capacitance being electrically coupled in series between each of the adjacent coplanar conductive unit elements in the array on said third layer, g. providing an inductive connection means which is arranged beside said capacitive surface means for enabling a substantially increased distributed inductance being electrically coupled in shunt between each of the coplanar conductive unit elements in the array on said third layer and said contiguous conductive plane on said fifth layer and with said base dielectric therein, h. providing at least one composite reference plane which is arranged by a three layers structure comprises said third layer, fourth layer and fifth layer to form a sufficient resonance circuit with said predetermined band gap frequency band by said capacitive surface means and said inductive connection means, i. providing a first miniature means which is originated from said inductive connection means for enabling a first ratio, alpha, of said thickness h.sub.r to the free space wavelength of at least one use frequency falling within said predetermined band gap frequency band of said composite reference plane, to be such that as to minimize thickness h.sub.r while providing said sufficient resonance circuit of said composite reference plane, and j. providing a second miniature means which is originated from said capacitive surface means for enabling a second ratio, beta, of the length of at least one side of the outer perimeter of each of the coplanar conductive unit elements and a third ratio, gamma, of the spacing d respectively to at least one use frequency falling within said predetermined band gap frequency band of said composite reference plane, to be such that as to minimize the length of the outer perimeter and the spacing d while providing said sufficient resonance circuit of said composite reference plane.
40. The method of claim 39 wherein said thickness h.sub.r of said base dielectric is equal or less than said thickness h1 of said first dielectric of said second layer.
41. The method of claim 39 wherein said inductive connection means comprises an opening, at least one coplanar inductive element and at least one coplanar terminal electrode inside each of the coplanar conductive unit elements on said third layer, and wherein said coplanar inductive element is positioned inside said opening and electrically connected in series between the perimeter of said opening and said coplanar terminal electrode, and wherein said coplanar terminal electrode is centrally positioned inside said opening and is a means for constituting an electrical coupling from said coplanar inductive element to said contiguous conductive plane through said base dielectric therein.
42. The method of claim 41 wherein said coplanar inductive element is made with at least one coplanar conductive wire structure originating from a centrally positioned origin.
43. The method of claim 41 further providing at least one conductive post which connects said coplanar terminal electrode and said contiguous conductive plane.
44. The method of claim 39 wherein said first miniature means associated with said thickness h.sub.r is arranged to provide said first ratio alpha of less than 0.02.
45. The method of claim 39 wherein said first miniature means associated with said thickness h.sub.r is arranged to provide said first ratio alpha of approximately from 0.001 to 0.0001.
46. The method of claim 39 wherein said second miniature means associated with the length of the outer perimeter is arranged to provide said second ratio beta of less than 0.1.
47. The method of claim 39 wherein said second miniature means associated with the length of the outer perimeter is arranged to provide said second ratio beta of approximately from 0.01 to 0.02.
48. The method of claim 39 wherein said second miniature means associated with the spacing d is arranged to provide said third ratio gamma of less than 0.01.
49. The method of claim 39 wherein said second miniature means associated with the spacing d is arranged to provide said third ratio gamma of approximately from 0.001 to 0.004.
50. The method of claim 39 wherein said conductor of said first layer is a transducer.
51. The method of claim 39 wherein said conductor of said first layer is an antenna, whereby said antenna is enabled to resonate at a substantially lowered frequency band in a constrained area which is constituted by said substantially thinner and more compact signal transmission device with said predetermined band gap frequency band which provides a means to integrate with electrical circuits and microelectronic devices that have constraints in dimensions and thickness and means practical for antenna miniaturization and antenna in package devices.
52. The method of claim 51 further providing a magneto dielectric materials positioned on top of said antenna.
53. The method of claim 39 wherein said conductor of said first layer is a transmission line, whereby a substantially close to 50 Ohm impedance transmission line is constituted over said substantially thinner and more compact signal transmission device with said predetermined band gap frequency band which provides a means for enabling substantially lowered transmission loss, substantially lowered impedance variation and substantially lowered reflection at either terminals of said signal transmission device.
54. The method of claim 53 further providing an upper dielectric positioned on top of said transmission line and a contiguous conductive plane positioned on top of said upper dielectric.
55. The method of claim 53 further providing an upper dielectric positioned on top of said transmission line and an upper composite reference plane positioned on top of said upper dielectric, wherein said upper composite reference plane is a vertically flipped replication of said composite reference plane of the signal transmission device.
Description
DETAILED DESCRIPTION OF THE DRAWINGS
[0020] The components in the figures are not necessarily to scale, emphasis being placed instead upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views.
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DETAILED DESCRIPTION
[0073] Metamaterial substrates are a new class of ordered artificial composites that exhibit ultra-thin dielectric thickness with exceptional electromagnetic properties not readily observed in conventional circuit materials that are used as ground, reference, or reflective planes in SiP modules and multilayer PCBs. Their precise shape, geometry, size, orientation, and arrangement can affect electromagnetic waves in a manner that exceeds the capabilities of conventional dielectric materials used in printed circuits. For example, their ultra-thin and ultra-small structure exhibit Electromagnetic Band Gaps (EBG) which can be integrated in microwave devices and SiP modules to improve performance. They can be used as circuit materials to design amplifiers, filters, power dividers, baluns, etc. They can be used in small outline and large format PCBs to provide reduced losses in transmission line structures. In addition to microwave devices, metamaterial substrates can be used in the design of antennas. Since they can provide EBG, metamaterial substrates can be used to enhance the isolation between closely packed Multiple Input Multiple Output (MIMO) antenna systems. They are also used to miniaturize antennas and to modify the characteristics of antennas.
[0074] In addition, metamaterial substrates can be used to produce materials with a user-designed electromagnetic response at a defined range of operating frequencies. This enables novel electromagnetic behaviors such as negative refractive index, lensing, absorbers, and invisibility cloaks. Such metamaterials can be classified as a Frequency Selective Surface (FSS) or Artificial Magnetic Conductor (AMC).
[0075] Metamaterial substrates can be realized by repeating a basic building block in a specific periodic pattern.
[0076] The advantages of using metamaterial substrates in antennas include:
[0077] 1. Provides EBG to modify the characteristics of antennas.
[0078] 2. Increases antenna efficiency and gain.
[0079] 3. Antenna miniaturization.
[0080] 4. Enhance the isolation between closely packed MIMO antenna systems.
[0081] 5. Reinforces radiation leading to a very highly directive beam.
[0082] Combining metamaterial substrates, antenna structures, miniaturization, and heterogeneous 3D integration of electronic circuits forming end-to-end, mixed-signal solutions may achieve antenna to baseband solutions. Thus, the use of metamaterial substrates offers the potential for large-scale adoption of wireless connectivity technologies through integration, size reduction, efficiency improvements and economies of scale and shortens design cycles for compact product designs.
[0083] Various applications of metamaterial substrates include: [0084] 1. Ultra-thin (e.g. as thin as 17 to 100 m) metamaterial inspired PCB laminates composite of ultra-small UE that may be combined with electronic circuit component or buried in any layer of multilayer PCBs by conventional lamination processes for circuit designs capable of transmitting, receiving and reflecting electromagnetic energy, altering electromagnetic properties of natural circuit materials, enhancing electrical characteristics of electronic components (such as filters, antennas, baluns, power dividers, transmission lines, amplifiers, power regulators, and printed circuits elements) in systems and sub-systems circuit designs. Ultra small UE may mean from 1 mm1 mm and up of UE and then arrayed in periodic order with a gap d as shown in
[0088] A metamaterial-inspired antenna may be composed with the following elements for antenna performance enhancement and antenna miniaturization. Some embodiments may be implemented as 3D-SiP or 3D-AiP depending on whether electronic components are embedded inside or mounted on the external layers of the PCBs. [0089] 1. Ultra-thin and ultra-small UE having practical dimensions for substrate embedding or PCB lamination processes. [0090] 2. The ultra-thin and ultra-small UE provides an EBG ground plane or EBG surface at the desired operating frequency. [0091] 3. Some embodiments may comprise magneto dielectric materials as a superstrate structure in the metamaterial-inspired antenna. The magneto dielectric materials act as superstrate to enhance permeability (e.g., .sub.r>1) which contributes to antenna miniaturization. [0092] 4. The size of the antenna element and antenna ground plane may be tremendously reduced by placing the antenna element on the top of a metamaterial substrate which exhibits EBG ground plane or surface. [0093] 5. The EBG surface with and without the combination of the magneto dielectric superstrate can provide a high miniaturization factor (.sub.r .sub.r) for antenna miniaturization and enable practical dimensions for 3D-SiP or 3D-AiP device. Practical dimensions of a 3D-SiP or 3D-AiP may mean 25 mm25 mm or less. Some embodiment of a 3D-SiP or 3D-AiP may be as small as 5 mm5 mm or less. [0094] 6. At least one of a SAW filter, lumped elements filter, and amplifier can be integrated with the metamaterial-inspired antenna to enhance radio cohabitation.
[0095] Metamaterial substrates may be realized by repeating a basic building block in a specific periodic pattern. The basic building block is known as the UE, and can define the basic properties of the metamaterial substrates.
[0096] EBG based metamaterials substrates are also referred to as Artificial Magnetic Conductors (AMC). Artificial magnetic materials are a branch of metamaterials which are designed to provide desirable magnetic properties which do not occur naturally. Such artificial structures are designed to provide, for example, either negative or enhanced positive (e.g., higher than one) relative permeability. Enhanced positive relative permeability, r>1, is very useful for antenna miniaturization.
[0097] In addition, the reflection phase of an incident wave is a characteristic of the AMC. The phase of the reflected electric field has a normal incidence which is the same phase of the electric field impinging at the interface of the reflecting surface. The variation of the reflection phase is continuous between +180 to 180 relative to the frequency. A zero occurs at one frequency, where resonance occurs. The useful bandwidth of an AMC is generally between +90 to 90 on either side of the central frequency. At this boundary condition, in contrast to the case of a conventional metal ground plane, an AMC surface can function as a new type of ground plane for low-profile wire antennas suitable for wireless communication systems. For example, when a horizontal wire antenna is extremely close to an AMC surface, the current on the antenna and its image current on the ground plane are in-phase, rather than out-of phase, thereby advantageously strengthening the radiation.
[0098] Smaller physical size, wider bandwidth, and higher efficiency are desirable parameters for antennas in wireless communications. Considering a patch antenna as an example, the size of the patch is proportional to the wavelength in the substrate which is inversely related to the factor:
{square root over (.sub.r.sub.r)}
where .sub.r and .sub.r are the relative permittivity and permeability of the substrate. Therefore, by using high dielectric material (a material with high permittivity, .sub.r) miniaturization can be achieved by the factor of .sub.r. However, since the wave impedance, Z is proportional to the ratio of r and .sub.r:
In this case, there can be a high impedance mismatch between the air and the substrate. Due to this mismatch, most of the energy will be trapped in the substrate resulting in narrow bandwidth and low efficiency. To solve this problem, instead of using high dielectric material (e.g., .sub.r>1), a substrate with magneto-dielectric material (both .sub.r>1, and .sub.r>1) can be used. By choosing moderate values for .sub.r and .sub.r, a high miniaturization factor (e.g., .sub.r .sub.r) can be achieved, while keeping the wave impedance close to that of air leading to less of a mismatch.
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[0102] Ultra-thin (e.g., 1/4000 o @ 2.45 GHz), and ultra-small metamaterial substrates can be designed for use in 3D-SiP or 3D-AiP devices. Referring back to
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[0104] Metamaterial substrates are artificial circuit materials, and may be referred to as Left-Handed Metamaterials (LHM). In some embodiments, the metamaterial substrates are ultra-small and ultra-thin and designed for use in mass-produced, low-cost products. As an example of practical dimensions, some embodiments may be practically constructed with organic PCB prepregs (e.g., sheets of B-staged resin with reinforcing fabric) having a thickness of 30 m to 300 m. In some embodiments, a copper conducting layer having a thickness of 5 to 18 m is possible. Ultra-thin EBG surface or metamaterial substrates can be manufactured using one-layer of PCB laminate. Each layer of PCB laminate in a multi-layer PCB may typically have a thickness of 30-200 m. Ultra-thin EBG surface or metamaterial substrates manufactured using one-layer of dielectric material may be integrated into 3D-SiP or 3D-AiP SiP or integrated into a multi-layer PCB.
[0105] By way of example and not a limitation, the size (x,y,z or W,L,h) of conventional UE may be in the scale of a few millimeters or even greater than 10 mm, however larger sizes may not be practical for 3D-SiP, 3D-AiP, and multi-layer PCB lamination process. As illustrated in
[0106] As illustrated in
[0107] Metamaterial substrates may have high effective values of relative permittivity and permeability. These characteristics enable a higher miniaturization factor (see e.g., the equation for miniaturization factor). Metamaterial substrates may permit reductions in physical lengths of electrically conducting elements such as antennas and filter and transmission line elements, because of the higher miniaturization factor. Some embodiments improve radiation efficiencies by reducing or even eliminating internal reflections (e.g., surface wave) between antenna elements and an EBG ground plane. Metamaterial substrate structures additionally may provide a very high Q-factor to electrically conducting elements. Metamaterial substrate structures may provide frequency band filtering functions that, for example, would normally be provided by other components typically found in an RF front-end. The high Q-factor to the electrically conducting elements may provide almost lossless transmission line elements such that the loss in the operating frequency range is extremely small.
[0108] With the increased left-handed shunt inductance, L.sub.L, formed by the coil, the W and L of the UE may be reduced to create a miniaturized UE 1.75 mm1.75 mm, as shown in
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[0110] Different dimensions of a sample coiled UE and free space wavelength are shown in Table 2. The ultra-thin and ultra-small coiled UEs can create an EBG surface of about 1-3 GHz.
TABLE-US-00002 TABLE 2 Mushroom .sub.o @ 2.45 GHz = 122.4 mm Size (W & Gap (d) Thickness (h) Band-gap Q (122400 m) L) (mm) (mm) (m) (GHz) Factor Conventional UE 15 1.5 3000 2~3 Compare to 0.1.sub.o 0.01 .sub.o 0.02 .sub.o free space (1/8 .sub.o) (1/80 .sub.o) (1/40 .sub.o) wavelength Coiled UE A with 1.75 0.5 30 972 MHz~3.698 GHz 200 dielectric thickness: 30 m .sub.r = 17 Compare to 0.01.sub.o 0.004.sub.o 0.00025.sub.o See. FIG. 10 free space (1/70 .sub.o) (1/245 .sub.o) (1/4080 .sub.o) wavelength Reduction 10 fold 3 fold 100 fold Coiled UE AA (an 1.75 0.175 23 or 25 1 GHz~3 GHz alternative to A) with dielectric thickness: 23 m or 25 m .sub.r = 18 Compare to 0.01.sub.o 0.0014.sub.o 0.0002 .sub.o free space (1/70 .sub.o) (1/699 .sub.o) (1/5321 o) wavelength Reduction 10 fold 7 fold 133 fold Coiled UE B (50 m) 2.4 0.2 50 756 MHz~2.64 GHz 71 .sub.r = 10 Compare to 0.02.sub.o 0.0016.sub.o 0.0004.sub.o free space (1/51 .sub.o) (1/612 .sub.o) (1/2448 .sub.o) wavelength Reduction 6 fold 8 fold 60 fold Coiled UE C (127 m) 2.4 0.2 127 1.5 GHz~3.1 GHz 423 .sub.r = 10 Compare to 0.02.sub.o 0.0016.sub.o 0.001.sub.o free space (1/51 .sub.o) (1/612 .sub.o) (1/964 .sub.o) wavelength Reduction 6 fold 8 fold 24 fold Coiled UE D (30 m) 2.4 0.2 30 1~3 GHz 24 .sub.r = 4.4 Compare to 0.02.sub.o 0.0016.sub.o 0.00025.sub.o free space (1/51 .sub.o) (1/612 .sub.o) (1/4000 .sub.o) wavelength Reduction 6 fold 8 fold 100 fold
[0111] Metamaterial substrates exhibiting EBGs operating in the desired frequency bands, from the lowest of 756 MHz to the highest of 3.698 GHz, are illustrated in the dispersion diagrams shown in
[0112] The EBG created with the UE A and AA described in Table 2 is shown in
[0113] In some embodiments, two separate coils of the UE turn in the opposite direction to increase the inductance L.sub.L. Such an arrangement is shown in
[0114] Two coiled UEs turning in the opposite direction may be stacked to form the double-layer coiled UE, as shown in
[0115] A surface mount chip inductor embedded inside the PCB may be used to replace the coil structure as shown in
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[0117] A patch antenna 2000 with geometry of about 5 mm5 mm may be overlaid on the top of the EBG ground plane or surface 2102 as shown in
[0118] In contrast, a comparable conventional miniature antenna design would necessarily be much larger to operate at 2.4 GHz. The reduction in antenna size over conventional antennas may be over 80-90%, in relation to the antenna body itself. A conventional miniature antenna needs a large ground plane to operate, for example, a ground plane of 5050 mm. So, if the size of the ground plane is also taken into consideration, the reduction in antenna size is over 98% in this example. Small antenna constructed over the metamaterial substrate can practically, in size and thickness, be integrated into a 3DSiP or 3D-AiP, or be integrated into a compact PCBs with other embedded electronic circuits and components.
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[0122] Combinations and permutations of the 3D embedded technology and integration of a miniaturized metamaterial substrate (e.g., EBG ground plane or surface) provide a Metamaterial-inspired 3D-AiP (Meta-AiP). Meta-AiP may enhance radio cohabitation, because of the increased isolation due to the intrinsic nature of metamaterial antennas and the integration of at least one of embedded filter(s), balun, and high linearity LNA with the metamaterial antenna inside of the Meta-AiP.
[0123] By way of example and not limitation, various methods of constructing metamaterial AiPs are illustrated below. For example,
[0124] Other combinations are possible. For example, the structure in
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[0135] Advantages of a Land Grid Array (LGA) package Meta-AiP with an antenna at the top of the module include: [0136] 1. Eliminates packaging and manufacturing process costs (no post assembly for plastic encapsulation or metal shield). [0137] 2. RF shielding may be embedded inside the 3D structure during the PCB fabrication process. [0138] 3. Metamaterials antenna may be embedded on the top surface of the package. [0139] 4. LNA, SAW, filters, antenna switch, and passives can be embedded. [0140] 5. Excellent RF performance. [0141] 6. Smallest footprint in the x-y dimensions. [0142] 7. Low profile from, for example, 0.6 mm-1 mm.
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[0145] Advantages of the Hybrid LGA Meta-AiP with lateral antenna include: [0146] 1. The thickness of metamaterials antenna may be increased to enhance performance. [0147] 2. Optional wireless chipset and cover can be added to the top to form a complete wireless module. [0148] 3. RF shielding can be embedded for internal structure during the PCB fabrication process. [0149] 4. LNA, SAW, filters, antenna switch, and passives can be embedded. [0150] 5. Excellent RF performance. [0151] 6. Low profile can be, for example, from 0.6 mm1 mm for active antenna and FEM applications.
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[0154] Magneto dielectric materials can also be integrated as a superstrate with the Meta-AiP as shown in
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[0167] The EBG-backed or 3-layer microstrip transmission line backed with the metamaterial substrate may be used to connect between an antenna element and other circuit elements, such as one or more of a balun, filter, or active semiconductor chip, in a circuit design. Such a configuration may reduce the power loss between each interconnection and to improve the overall system performance and power efficiency.
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[0177] While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of this invention.