Nokia Technologies OY v Telecommunications Corp, Ltd & Ors. - [2022] EWHC 2814 (Pat)

A patent claiming a programmable low-pass filter in a polar transmitter is construed by reference to the claim language and the skilled team’s technical understanding, rather than by confining the claims to preferred embodiments. “Integrated” requires a sufficiently proximate functional and physical relationship, not necessarily a single integrated circuit. A claim requiring filtering means suitable for filtering, rather than proof that filtering has actually occurred. Obviousness must be assessed without hindsight and by reference to the concrete teaching of the prior art. A conceptual leap from fixed-bandwidth systems to dynamically varying filtering in LTE was not obvious where the alleged motivation depended on an unestablished worst-case resource-block scenario.

Nokia alleged that Oppo mobile phones infringed European Patent (UK) No 3 716 560 B1, an implementation patent concerning power-supply circuitry in polar transmitters. Oppo denied infringement and challenged validity on obviousness and sufficiency grounds, relying principally on Jarvinen, Arayashiki and Hadjichristos. Nokia also proposed two amendments and alleged infringement of dependent claim 6.

During trial Oppo conceded infringement of claim 1 on the relevant construction, subject to the court’s determination of claim scope. The central issues were the meaning of “integrated”, the scope of “for low-pass filtering”, whether the patent was obvious over the prior art in the context of LTE, the construction and validity of claim 6, and the allowability of the proposed amendments.

1. Disposition. Claim 1 was infringed by the Oppo phones with software used before the Update. Claim 6 was not infringed. The Patent was valid as granted, and neither proposed amendment was allowed.
2. Claim construction. The claims were not confined to the illustrated embodiments. “Integrated” required a sufficiently proximate functional and physical relationship such that the components worked together in generating the power-supply signal. It did not require all components to be on the same integrated circuit. An LC filter at the output of an SMPS could therefore satisfy the relevant integer. “For low-pass filtering” meant suitable for filtering; actual filtering was unnecessary.
3. Common general knowledge and obviousness. The skilled team designing an LTE transmitter would obtain the relevant resource-block information from the standards. Nevertheless, the proposition that one resource block might be placed at the channel edge with full permitted power was not common general knowledge or a natural starting point. The obviousness case depended on that proposition and on an artificial abstraction of the prior art. The court applied the Pozzoli analysis and the approach in Actavis v ICOS, allowing for the fact that implementation could be carried out by the skilled team but rejecting hindsight.
4. Prior art. Jarvinen disclosed a variable filter for multimode systems, not dynamic resource-block allocation in LTE. Hadjichristos disclosed a variable filter for production variation in GSM/EDGE. Neither supplied a concrete or non-hindsight reason to redeploy the teaching for the claimed LTE purpose. Arayashiki was not separately considered because Oppo accepted it would not succeed if Jarvinen failed.
5. Claim 6. A feed-forward path had to be identified by reference to the input and output of the SMPS and had to be within the SMPS. The alleged arrangement did not satisfy that requirement. The attack on validity also failed, substantially for the reasons already given on claim 1.
6. Amendments. Amendment A lacked sufficient clarity and risked altering the meaning of “integrated”. Amendment B added matter because it extracted an RC-filter feature from a specific embodiment without a clear and unambiguous basis.