Obviousness

Obviousness Analysis of US Patent 8,350,763 Under 35 U.S.C. § 103

This analysis examines whether the claims of US Patent 8,350,763 (hereinafter '763 patent) would have been obvious to a person having ordinary skill in the art (PHOSITA) as of its priority date (August 14, 2008), based on combinations of prior art references acknowledged or discussed within the '763 patent itself. A PHOSITA in 2008 would likely be an electrical engineer or antenna designer with expertise in wireless communications, RF circuits, tunable components, impedance matching, and multi-band antenna design.

The '763 patent identifies its core innovation as enabling a "single antenna to be used for simultaneous transmission (or reception) for multiple bands" in wireless portable devices, stating that prior art had not contemplated this simultaneous multi-band operation on a single antenna. Previous actively tuned antenna solutions, such as those described in U.S. Pat. No. 7,369,828 ('828 patent) and U.S. Pat. No. 7,369,829 ('829 patent), were characterized as tuning either distinct antennas for high and low bands, or a single antenna for one band at a time (e.g., a single cellular telephone call).

Combination of Prior Art References

A compelling combination of prior art that would render the claims of the '763 patent obvious would include:

1. U.S. Pat. No. 7,369,828 ('828 patent) by Shamsaifar (Paratek Microwave): This patent discloses an electronically tunable multiple band antenna system. Specifically, it describes "providing a high band antenna with at least one voltage tunable varactor associated therewith, ...; providing a low hand antenna with at least one voltage tunable varactor associated therewith, ...; and inputting control data to the controller and controlling a first bias voltage for biasing the at least one voltage tunable varactor associated with the high band antenna and a second bias voltage for biasing the at least one voltage tunable varactor associated with the low band antenna" [Definitions: a method of transmitting and receiving RF signals...]. The '828 patent uses a controller to tune active elements (varactors) for operation across multiple cellular bands (e.g., quad-band cellular) [Definitions: the multiple band antenna is a quad band antenna...]. The underlying tunable dielectric materials (e.g., BSTO) and their use in tunable capacitors are also well-established by Paratek and Sengupta et al.'s patents cited in the '763 patent-.
2. General knowledge in the art concerning RF signal management and isolation (e.g., D. Pozar's books "Microwave Engineering" and "Microwave and RF Design of Wireless Systems", IEEE conference teachings): These resources teach fundamental RF engineering principles, including the design and use of splitters, combiners, couplers, mixers, switches, filters (including trap circuits), and buffer/tuned amplifiers. Such components are crucial for routing, combining, separating, and isolating RF signals.
3. The existing problem of multiple antennas in wireless portable devices: The '763 patent explicitly highlights this problem: "Today's cellphones and laptops typically require multiple antennas, each antenna designed for resonance or desired performance at a particular frequency band... Computer makers and cellphone makers have difficulty with the mechanical design of their equipment... it is not inconceivable to eventually have wireless portable devices requiring 10 or more separate frequency bands...".

Motivation for Combination

The motivation for a PHOSITA to combine the '828 patent with general RF signal management techniques would be to address the persistent and growing problem of physical space constraints, mechanical design complexity, and increased bill of materials associated with using multiple dedicated antennas for an increasing number of wireless communication bands in portable devices. The '763 patent itself articulates this challenge and states that it "greatly simplifies the mechanical design and layout of wireless portable devices by allowing multiple transmitter (or receiver) bands to simultaneously use one or more antennas for simultaneous multi-purpose use".

A PHOSITA, aware of the active tuning capabilities demonstrated by Paratek ('828 patent) for multi-band operation (albeit often on separate antennas or one band at a time), would naturally seek to extend these benefits to further reduce antenna count by enabling simultaneous multi-band operation on a single physical antenna structure.

Specific motivations for combination and how they render claims obvious:

• Miniaturization and Space Saving: The '828 patent already demonstrated the advantage of tunable elements to achieve multi-band operation, thus avoiding the need for a separate fixed-tuned antenna for every single frequency within a band. Extending this concept to a single antenna for all bands, rather than separate high-band and low-band antennas as in '828, would be a logical next step for space-constrained portable devices.
• Simultaneous Multi-Band Operation: While '828 focused on one-at-a-time operation for cellular calls, the preamble of the '763 patent acknowledges the need for new standards like IEEE 802.11ad, which might require simultaneous capabilities in 2.4 GHz, 5.8 GHz, and 60 GHz bands. A PHOSITA would recognize that to achieve this simultaneous operation on a shared antenna, known RF techniques for managing multiple signals (e.g., using splitters to feed a single antenna from multiple transceivers, as shown in FIG. 3 of the '763 patent) would be necessary. The '763 patent itself describes the use of "individual RF tuners 30, 32, and 34" for different transceivers, feeding a single antenna, and mentions that "input signals are split and routed to each of the respective tuner circuits, and may use a Wilkinson or simple ohmic splitter". These are well-known techniques.
• Isolation Requirements: The '763 patent explicitly states that a "key to proper operation is to also, while providing good matching, provide sufficient RF isolation so that the transmitters in other hands do not overload the front end receiver of a band that is receiving". A PHOSITA would know that achieving simultaneous multi-band operation on a single antenna would necessitate robust isolation. The '763 patent suggests solutions like adjusting the tuner for high impedance at other bands, using "low cost LC circuits... to create an RF Trap," "buffer amplifiers, tuned amplifiers, as well as tuned trap circuits," and "RF antenna switches". These are all standard RF components and techniques taught in general RF engineering literature (e.g., Pozar) and known to a PHOSITA. Furthermore, the use of frequency selective surfaces (FSS) or metamaterials for isolation, as referenced by Ragan et al. in US patent publication 20080238801, further strengthens the obviousness of achieving isolation.
• Controller Functionality (Claims 4, 6, 17): The '828 patent already teaches a controller providing bias voltages to tune varactors. A PHOSITA would find it obvious to expand the functionality of such a controller to manage multiple tuners or a more complex single multiband tuner to facilitate simultaneous operation across multiple bands, especially given the availability of increasingly integrated multiband transceiver chips (as noted in the '763 patent, FIG. 4 and its description). The controller's functions described in '763, such as receiving feedback, adjusting control signals, and managing power, are standard for optimizing performance in active RF systems.
• Simultaneous Matching (Claim 10): The requirement for a tuner to match an antenna to a transceiver "simultaneously" across multiple bands (Claim 10) is a direct consequence of implementing simultaneous multi-band operation on a single antenna. Given the existing tunable antenna technology ('828, Paratek, Agile) and the clear need for multi-band devices, a PHOSITA would be motivated to develop or adapt impedance matching networks to achieve this simultaneous matching, utilizing the known active elements and control systems. The description of individual tuners for each band in FIG. 3, which collectively feed a single antenna, implicitly teaches a system capable of simultaneous matching.

In summary, the '763 patent takes the known concept of actively tuned multi-band antennas (as taught by '828) and applies it to a single antenna for simultaneous multi-band operation. This extension is motivated by well-recognized problems in the art (space, cost, complexity) and is achieved by combining existing active tuning techniques with conventional RF signal splitting, combining, switching, and isolation methods, which are all within the purview of a PHOSITA.