Obviousness

Obviousness Analysis of US11728564 Under 35 U.S.C. § 103

This analysis evaluates the obviousness of US patent 11728564 by identifying combinations of elements implicitly known in the prior art, as described within the patent's own disclosure, and articulating the motivation for a person having ordinary skill in the art (PHOSITA) to combine them. The prior art date is November 27, 2019.

The patent itself describes the existing state of the art and the problems it seeks to solve. For instance, it notes that "smartphones include a circuit and an antenna for enabling near field RF communication (NFC)" and "a circuit and an antenna for magnetic secure transmission (MST) are applied to sonic smartphones". It further highlights that "spaces for installing an NFC antenna or MST antenna are limited. This requires additional efforts for designing antennas' structures and layout of components in smartphones" due to other components like batteries and metal housings. This establishes the recognized need for compact and efficient antenna designs in smartphones.

Analysis of Independent Claims 1 and 19

Claims 1 and 19 define a smartphone antenna module comprising a flexible PCB with coil antennas and a magnetic sheet, specifically detailing their structural arrangement.

Combination of Prior Art Elements:

A PHOSITA, at the time of the invention (prior to November 27, 2019), would have been aware of the following individual elements and their functions, as acknowledged within the patent's own disclosure:

1. Flexible PCBs for Antennas: The patent states that "a flexible antenna module or apparatus 100 is formed in a single, thin, flexible body in which coil antennas for providing an MST antenna and an NEC antenna are integrated" and explicitly mentions "a flexible PCB 200 with coil antenna (coil A) 204 and coil antenna (coil B) 206 for providing the MST antenna and the NFC antenna". This establishes that using flexible PCBs to integrate coil antennas for MST and NFC applications was known or contemplated in the art.
2. Coil Antennas and Through Holes: The patent describes a "flexible PCB 200 has a rectangular sheet shape with a through hole 202 at its center" and that "the first coil antenna 204 surrounds or encircles the through hole 202". This indicates that the concept of coil antennas surrounding holes in PCBs was known.
3. Nested Coil Antennas: The disclosure also mentions that "the second coil antenna 206 surrounds encircles the first coil antenna 204 and the through hole 202". This demonstrates that arranging multiple coils in a nested fashion was a known design option.
4. Magnetic Sheets as Antenna Cores: The patent clearly states that "a magnetic sheet 300 which is engaged with the flexible PCB 200" and that "the magnetic sheet may function as a magnetic core when the magnetic sheet passes through a through hole that a coil surrounds or the magnetic sheet is placed adjacent a coil". It also discusses various magnetic materials like ferrite and nanocrystal laminates. This establishes the known use of magnetic sheets to enhance antenna performance and their integration with PCBs.
5. Magnetic Sheet Passing Through a Hole: The patent explicitly describes that "the head portion 304 of the magnetic sheet 300 passes through the through hole 202", directly demonstrating this structural arrangement.
6. Magnetic Sheet Portions Overlapping Coil Segments on Opposite Sides of a Hole: The patent details that "the head portion 304 has a first sheet portion 320 placed over a first PCB section 220 of the flexible PCB while the base portion 302 has a second sheet portion 322 placed under a second PCB section 222 of the flexible PCB", with these sections being "on opposite sides of the through hole 202". Furthermore, it states that "the first sheet portion 320 overlaps coil portions of the first coil antenna 204 which are located in the first PCB section 220" and "the second sheet portion 322 overlaps coil portions of the first coil antenna 204 which are located in the second PCB section 222".

Motivation for a PHOSITA to Combine:

A PHOSITA, seeking to overcome the challenges of "limited spaces for installing an NFC antenna or MST antenna" and to achieve "improved layout arranging the NEC antenna and the MST antenna" in a smartphone, would have been motivated to combine these known elements.

• To create a compact, integrated antenna: Combining multiple coil antennas (for MST/NFC) on a single flexible PCB is a logical step to save space and simplify manufacturing.
• To enhance antenna performance in limited space: Incorporating a magnetic core is a known technique to increase inductance and efficiency of coil antennas, particularly for lower frequency applications like MST and NFC, without significantly increasing their physical footprint.
• To maximize magnetic coupling efficiently: When using a magnetic sheet as a core for a coil surrounding a through-hole, a PHOSITA would find it obvious to thread a portion of the magnetic sheet through the hole. This maximizes the magnetic flux linkage with the coil.
• To optimize the magnetic core's interaction with the coil: Structuring the magnetic sheet with distinct "head" and "base" portions that pass through the hole and are positioned on opposite sides of the flexible PCB, overlapping the coil segments in those sections, is a straightforward engineering approach. This ensures effective magnetic coupling with the coil turns distributed across the PCB and around the central opening.
• Refinements for spatial efficiency (Claim 19 specific): The introduction of a "neck portion" in the magnetic sheet (explicitly mentioned in the patent as existing, e.g., "the magnetic sheet further includes a neck portion between the base portion and the head portion") is a logical refinement for a magnetic core that passes through a hole. The specific arrangements where parts of the second coil antenna "do not overlap the magnetic sheet," "overlap the magnetic sheet," or "cross over the magnetic sheet" are evident design choices for a PHOSITA when optimizing coil placement for desired performance characteristics and to navigate spatial constraints in a multi-layered, compact system. The patent itself describes scenarios where a coil "does not include a conductive line portion that overlaps the head portion" but "overlaps the base portion", and where a line segment "crosses coil V", demonstrating these are known design considerations.

Therefore, the arrangements described in independent claims 1 and 19, which integrate a flexible PCB with nested coils surrounding a hole, and a magnetic sheet specifically shaped (with head, base, and optional neck portions) to pass through the hole and strategically overlap/interact with coil segments, would have been obvious to a PHOSITA driven by the known needs for compact and high-performance smartphone antennas.

Analysis of Independent Claims 16 and 22

Claims 16 and 22 describe a smartphone incorporating one of the antenna modules of claims 1 or 19.

Combination of Prior Art Elements:

Beyond the antenna module itself, the additional elements for the smartphone are also implicitly known from the patent's disclosure:

1. Standard Smartphone Components: A smartphone comprising "a display module comprising a display surface" and "a rear wall facing away from the display surface" are fundamental and well-known components of any smartphone.
2. Non-Magnetic Rear Walls: The patent explicitly discusses that "the rear cover can be made of non-metal material, for example, a plastic resin. Generally, non-metal rear covers do not interfere with wireless communications". This highlights the known advantage of non-magnetic materials for smartphone rear covers in the context of wireless communication.
3. Parallel Arrangement of Components: The general principle of arranging internal components, including antennas, parallel to the smartphone's display and rear wall is a fundamental design constraint for thin, planar devices. The patent explicitly states "the magnetic sheet is arranged generally parallel to the rear wall".

Motivation for a PHOSITA to Combine:

Once the antenna modules described in claims 1 or 19 are considered obvious, their integration into a smartphone is a straightforward and obvious step for a PHOSITA.

• Standard Device Integration: It is conventional practice to incorporate antenna modules into a smartphone housing, typically near the rear cover to facilitate signal transmission and reception.
• Optimizing Antenna Performance in a Smartphone Environment: A PHOSITA would naturally select a "non-magnetic material" for the rear wall when integrating an antenna module that utilizes a magnetic sheet, precisely to avoid interference, as explicitly taught by the patent itself.
• Space-Efficient Layout: Arranging the planar magnetic sheet "generally parallel to the rear wall" is the most logical and efficient way to position such a component within the typically thin and rectangular form factor of a smartphone.

Therefore, combining an obvious antenna module with a smartphone having a display and a non-magnetic rear wall, where the magnetic sheet is arranged parallel to the rear wall, would be obvious to a PHOSITA.

Obviousness of Dependent Claims

Many dependent claims introduce specific design choices or well-known engineering optimizations that would be obvious to a PHOSITA:

• Specific widths/dimensions for magnetic sheet portions (Claims 2, 20): Specifying the relative widths of the magnetic sheet's head and base portions to allow passage through a hole (with or without bending) is a routine mechanical design optimization for assembly and form factor, driven by manufacturing and packaging considerations.
• Magnetic sheet extensions (Claims 6, 7): Whether the magnetic sheet extends beyond a PCB edge is a design choice influenced by the desired antenna performance characteristics and overall space budget.
• Electrical connections and current directions (Claims 8, 9, 10, 13, 14, 15): Connecting coils in series or parallel, and designing current flow directions (e.g., opposite rotational directions, same linear direction) to achieve desired magnetic field properties (e.g., field reinforcement or cancellation) are fundamental principles of electromagnetic design for antennas. The patent explicitly states these are known possibilities: "two coils among the multiple are electrically connected... in series" or "in parallel". Regarding the inconsistency in Claim 14 (referring to "third coil" and "second hole"), if interpreted as a drafting error referring to the second coil and first hole, the principle of controlling current directions in connected coils remains an obvious design choice for a PHOSITA.
• Multi-layer PCBs and additional coils (Claim 12): Using multi-layer PCBs to incorporate additional coils (e.g., a "fourth coil" surrounding the first hole in a different layer) for increased antenna length, bandwidth, or performance is a common technique in advanced PCB design, especially when compact solutions are required. The patent mentions "the flexible PCB may comprise a first layer and a second layer stacked over each other, wherein the first layer comprises the first and second coils, and the second layer comprises a fourth coil".
• Specific frequencies and functions (Claims 18, 21): Assigning the first coil to MST (85-100 KHz) and the second coil to NFC (13.56 MHz) is a direct application of known communication standards and the understanding that different antennas are tuned for different frequency ranges. The patent explicitly states these functional assignments: "a first one of the multiple coils is used as an MST antenna", "a second one of the multiple coils is used as an NFC antenna".
• Connection lines crossing over coils (Claim 11): Managing the routing of connection lines on a multi-layer flexible PCB, including routing them over existing coils while ensuring electrical insulation, is a routine aspect of PCB layout design, especially in high-density, compact modules. The patent notes that "Connector lines are insulated from the coil antennas 204 and 206 that they are crossing via insulation layers".

Conclusion

Based on the explicit and implicit disclosures within US patent 11728564 itself, a PHOSITA would have been motivated to combine known elements such as flexible PCBs, multiple coil antennas (including nested configurations and coils surrounding holes), magnetic sheets acting as cores, and the physical integration techniques for these components. The desire to create compact, high-performance MST and NFC antenna modules for space-constrained smartphones would drive a PHOSITA to arrange these elements in the claimed configurations, including the specific interaction between the magnetic sheet (with its head, base, and neck portions) and the coil segments. The dependent claims further represent obvious design choices and well-known engineering practices for optimizing such an antenna system. Therefore, the claims of US11728564 are rendered obvious under 35 U.S.C. § 103 by a combination of the prior art explicitly and implicitly described within the patent's own specification.