Obviousness

Obviousness Analysis under 35 U.S.C. § 103

A patent claim is considered obvious under 35 U.S.C. § 103 if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date to a person having ordinary skill in the art (PHOSITA). This analysis considers whether there was motivation in the prior art to combine elements to achieve a successful result.

The present patent, US11495875B1, details a smartphone antenna module primarily characterized by the arrangement of multiple coils on a flexible PCB in conjunction with a magnetic sheet, particularly for NFC and MST applications.

Combination 1: Flexible PCB Antennas with Multiple Coils and Magnetic Material

References:

• US6593900B1 (Flexible printed circuit board antenna): Discloses an electromagnetic antenna on a flexible PCB having multiple conductive levels and electrical traces forming helices, suitable for non-planar surfaces.
• US10062484B2 (Flexible soft magnetic core, antenna with flexible soft magnetic core and method): Describes an antenna coil with a flexible soft magnetic core and at least one winding wound around it. It mentions that the antenna winding can be formed by printed wiring on a flexible film surrounding the magnetic core.
• "Flexible printed circuit board (FPC) antennas for mobile phone operation" by Wu et al. (2010): Shows FPC meander antennas for multi-band design in mobile phones.
• US20050259031A1 (Multi-band monopole antenna for a mobile communications device): Teaches multi-band antennas on a substrate material such as a flex-film substrate, for mobile communication devices.

Rationale for Combination:
A PHOSITA in the field of smartphone antenna design, seeking to optimize antenna performance and reduce space, would have been motivated to combine the teachings of these references.

1. Flexible PCB Antennas in Smartphones: It is well-known in the art to use flexible PCBs for antennas in mobile devices, as demonstrated by Wu et al. and US20050259031A1, due to their ability to conform to internal device geometries. US6593900B1 explicitly teaches electromagnetic antennas comprising flexible PCBs with multiple conductive levels and helices for non-planar surfaces.
2. Incorporation of Magnetic Material for Enhanced Performance: US10062484B2 teaches the use of a flexible soft magnetic core with antenna windings wound around it to enhance antenna performance. A PHOSITA would recognize the benefits of incorporating such a magnetic core to improve inductance and efficiency, particularly for low-frequency applications like NFC and MST, which are known to be constrained by space within smartphones.
3. Multiple Coils for Multiple Frequencies (NFC/MST): The present patent explicitly states that smartphones include both NFC and MST antennas, which use different low-frequency bands and require larger antenna sizes, leading to design challenges. The concept of multi-band antennas on flexible substrates is already known, as shown in US20050259031A1. Therefore, a PHOSITA would be motivated to integrate multiple coils on a single flexible PCB to support different communication protocols (e.g., NFC at 13.56 MHz and MST at 85-100 KHz) within a compact smartphone environment. The prior art's emphasis on flexibility and multi-band operation provides a clear motivation for combining these elements.

Obviousness of Claim 1 (Smartphone Antenna Module):
Claim 1 describes a flexible PCB with first, second, and third coils, where the first and third are side-by-side and the second surrounds them, along with a magnetic sheet having portions that overlap specific coil sections and pass through a through-hole.

• The use of a flexible PCB with multiple coils for different communication functions (e.g., MST and NFC) would be obvious given the teachings of flexible antennas in mobile phones (Wu et al., US20050259031A1) and the known need for both MST and NFC functionality in smartphones.
• The concept of a magnetic sheet associated with coils to improve antenna performance is taught by US10062484B2.
• The specific arrangement of coils (first and third side-by-side, second surrounding both) and the magnetic sheet (first portion over first PCB section, second portion under second PCB section overlapping coils, intermediate portion through a hole) would be an obvious design choice for a PHOSITA optimizing space and magnetic coupling. The use of through-holes in PCBs for routing or component placement is a standard practice, and shaping a magnetic sheet to interact with coils and pass through such holes would be a predictable engineering solution to integrate the magnetic material effectively with the flexible PCB and its coil arrangement.

Obviousness of Claim 17 (Smartphone):
Claim 17 specifies a smartphone with a display, the antenna module of Claim 1, and a non-magnetic rear wall, where the magnetic sheet is parallel to the rear wall and specific portions are interposed between the rear wall and PCB sections.

• Integrating an antenna module into a smartphone with a display and rear wall is fundamental to smartphone design.
• The placement of the magnetic sheet parallel to the rear wall and its interposition between the rear wall and various PCB sections would be an obvious arrangement for a PHOSITA to achieve optimal antenna performance, given the design constraints of a smartphone. This configuration minimizes interference and maximizes the benefit of the magnetic material by placing it strategically relative to the antenna coils and the non-magnetic rear wall.

Obviousness of Claim 18 (Smartphone Antenna Module - Alternative Configuration):
Claim 18 focuses on a flexible PCB with a through-hole, a first coil surrounding it, a second coil surrounding the first, and no electrical connection between them. It also specifies a magnetic sheet with a head portion passing through the hole and a wider base portion, with specific overlaps.

• The idea of multiple, electrically decoupled coils on a flexible PCB for different antenna functions (e.g., MST and NFC, which often operate independently) would be obvious. The patent itself notes that "there is no electric connection between the first coil antenna 204 and the second coil antenna 206 in the antenna module." This suggests a known architectural choice.
• The magnetic sheet's head portion passing through a through-hole and a wider base portion overlapping coils is a logical extension of integrating magnetic material, as taught by US10062484B2, to maximize magnetic coupling within a constrained space. The design choices for the dimensions of the head and base portions (e.g., head portion smaller than the hole, base portion wider than the hole) are straightforward engineering decisions to allow for insertion while providing a larger magnetic area where needed.

Obviousness of Claim 26 (Smartphone - Alternative Configuration):
Claim 26 describes a smartphone with the antenna module of Claim 18, a display, and a non-magnetic rear wall, with specific interpositions of the magnetic sheet and PCB sections relative to the rear wall.

• Similar to Claim 17, this is an obvious application of the antenna module of Claim 18 within a smartphone, with the magnetic sheet positioned to interact effectively with the rear wall and PCB sections.

Obviousness of Claim 27 (Smartphone Antenna Module - Distinct Coil Relationships):
Claim 27 details the relationship between the second coil and the third coil, specifically mentioning a line of the second coil crossing the third coil while the first line does not, ensuring the entire third coil is between a second line of the second coil and the second segment of the first coil.

• While highly specific, the detailed routing of conductive lines on a flexible PCB to achieve particular spatial relationships and electromagnetic coupling characteristics is a standard practice in antenna design. Given the known need for compact, multi-functional antennas (NFC/MST) within smartphones, a PHOSITA would routinely optimize coil placement and routing, including crossing techniques (insulated, of course), to minimize space and maximize performance. The goal of fitting multiple coils and magnetic material within tight smartphone confines would provide ample motivation for such precise routing.

Obviousness of Claim 34 (Smartphone Antenna Module - Magnetic Sheet Shape and Coil Overlap):
Claim 34 specifies the magnetic sheet having head, neck, and base portions with different widths and specific overlaps with first and second coil segments in different PCB sections, where the third coil is positioned between segments of the first and second coils.

• The varied widths of the magnetic sheet portions (head, neck, base) are obvious design choices to facilitate insertion through a through-hole and provide optimal magnetic coverage for different coil sections. This is an engineering optimization based on the integration of a magnetic core (US10062484B2) with a flexible PCB antenna.
• The precise overlapping of specific coil segments with these magnetic sheet portions, and the placement of the third coil, represent further optimizations of the overall antenna module. Such arrangements are predictable efforts by a PHOSITA to enhance magnetic coupling for the various coils (NFC, MST, etc.) while adhering to spatial constraints.

Conclusion

Based on the cited prior art, a PHOSITA would have been motivated to combine the teachings of flexible PCB antennas, the use of magnetic materials to enhance antenna performance, and the need for multiple communication functionalities (like NFC and MST) within a compact smartphone. The specific structural arrangements of coils and magnetic sheets described in the independent claims, while detailed, represent predictable engineering solutions and optimizations for integrating these known elements into a functional and space-efficient smartphone antenna module.