Obviousness

Due to the absence of specific prior art patent or publication numbers within the provided "Prior art keywords" or "Definitions" section of US11031677B2, a detailed obviousness analysis combining specific prior art documents cannot be performed. However, based on the patent's own description of the state of the art and the problems it seeks to solve, a hypothetical obviousness argument under 35 U.S.C. § 103 can be constructed.

Background in the Art (as described by US11031677B2)

The patent describes a landscape where multifunction wireless devices (MFWDs), including multimedia terminals (MMT) and smartphones (SMRT), were prevalent. These devices often featured movable bodies (e.g., clamshell, slide, twist configurations) and increasingly sophisticated functionalities, requiring compact, multi-band, and efficient antenna systems. Key challenges in the prior art included:

• Maintaining performance (e.g., bandwidth, gain, efficiency) in small antennas due to fundamental physical limits related to volume.
• Achieving multi-band operation, particularly for broad bands like UMTS, within limited space without performance degradation or increased size.
• Overcoming the limitations of suitable antenna types for slim/movable devices, such as patch antennas (including PIFA), which were known for poor gain and narrow bandwidths.
• Integrating antennas efficiently alongside other electronic components and additional antennas, while meeting strict size, weight, and battery consumption constraints.
• The general understanding that increased gain and directivity often required larger antenna sizes, contrasting with the need for omni-directional patterns in portable devices.

The patent itself lists "antenna, contour, rectangle, wireless device, complexity" as prior art keywords, indicating that these concepts were known in the field before the 2006-07-18 priority date.

Hypothetical Combination of Prior Art for Obviousness

To establish obviousness for the claims of US11031677B2, a person having ordinary skill in the art (PHOSITA) would likely combine the following types of generic prior art, based on the problems and solutions described in the patent:

1. Prior Art Reference A: A Multifunction Wireless Device (MFWD) with a Movable Body (e.g., a generic mobile phone patent or commercial product from pre-2006).

   • This reference would disclose an MFWD featuring an upper and a lower body adapted to move relative to each other (e.g., clamshell, slide, or twist). It would also include multimedia and/or smartphone functionalities, encompassing components like a microprocessor, operating system (capable of running productivity applications), memory (e.g., greater than 1GB), a receiver for sound signals, and an image recording system (e.g., with a 2 Megapixel sensor, flash, or zoom capabilities), as well as data storage (e.g., greater than 1GB). Such devices were widely available and documented in various forms prior to 2006.

2. Prior Art Reference B: Known Antenna Design Techniques for Compact, Multi-band Antennas (e.g., an antenna engineering textbook or patent illustrating antenna shaping for mobile devices from pre-2006).

   • This reference would teach established methods for designing antennas to operate in multiple frequency bands (e.g., GSM, UMTS) within limited spatial volumes. It would describe techniques such as introducing slots, gaps, slits, cuts, or apertures into conductive plates; removing portions of the antenna structure; bending, folding, or curving antenna parts; meandering, sinuous, zig-zagging, or curving the perimeter; and employing multiple coupled antenna elements. These techniques were known means to achieve miniaturization, multi-band resonance, and impedance matching, addressing the inherent trade-offs between antenna size and bandwidth.

3. Prior Art Reference C: Methods for Quantifying Geometric Complexity (e.g., a technical paper or textbook discussing fractal geometry, box-counting methods, or other metrics for shape complexity from pre-2006).

   • This reference would disclose methods for characterizing the geometric complexity of two-dimensional or three-dimensional shapes. Such methods could include grid-based counting techniques (similar to those described for F21 and F32 in the patent), fractal dimension calculations, or other means to quantify "edge-richness, angle-richness and/or discontinuity-richness" of a contour at different levels of scale.

Motivation to Combine and Obviousness Rationale

A PHOSITA in antenna design, seeking to improve the performance of antennas in compact, multi-body MFWDs (Reference A), would have been highly motivated to apply known antenna shaping techniques (Reference B). The patent explicitly states the desire "to provide an enhanced wireless connectivity" and "to optimize the efficiency of an antenna for a MFWD device while observing the constraints of small device size and enhanced performance characteristics". The recognized shortcomings of conventional antennas, such as the narrow bandwidth of PIFAs for UMTS operation in slim devices, would further compel a PHOSITA to explore advanced geometries.

Given that the "complexity" of antenna shapes was a known concept in the prior art, and that engineers frequently sought to maximize surface area within a given volume to improve bandwidth, a PHOSITA would naturally experiment with more intricate antenna contours. If methods for quantifying geometric complexity (Reference C) were known or readily derivable, a PHOSITA would be motivated to utilize such quantitative analysis to systematically design and optimize antenna shapes. Such quantification would allow for a more objective comparison and refinement of various complex geometries (e.g., meanders, slots, multiple branches) beyond qualitative assessment.

The specific parameters F21 and F32, as defined in the patent, are presented as tools to "capture and characterize certain aspects of the geometrical details of the antenna contour... when viewed at different levels of scale" and to guide antenna design and optimization. The patent even suggests that these "parameters may also be used in numerical optimization algorithms as target values or to define target intervals in order to speed up such algorithms".

Therefore, a PHOSITA, aiming to optimize antenna performance (multi-band, broadband, efficiency, gain, miniaturization, isolation) in a movable MFWD (Reference A) using known shaping techniques (Reference B) and informed by methods of quantifying geometric complexity (Reference C), would have been motivated to iteratively design and test various complex antenna contours. Through routine experimentation and optimization, a PHOSITA could reasonably arrive at antenna designs whose contours fall within the claimed ranges for complexity factors F21 (1.05-1.80) and F32 (1.10-1.90). The selection of these specific ranges, while beneficial, would be considered an obvious result of such a systematic optimization process, driven by the known engineering objectives for mobile device antennas.

For example, a PHOSITA aware that highly convoluted perimeters (which would increase F32) can aid miniaturization and broad frequency response, and that branched structures (which would increase F21) can improve multi-band operation, would be motivated to combine these features. The discovery of specific quantitative ranges (F21 and F32) that yield optimal results within these design goals would be an expected outcome of applying known design principles and optimization techniques to address known problems in the art.