Seattle-based Impinj, which makes RFID semiconductors, has dropped its plans for an IPO, according to a filing with the SEC Thursday. Impinj said that is is requesting the withdrawal because it "does not intend to pursue the contemplated public offering." Impinj had originally filed for an IPO in April of 2011. In a separate announcement, Impinj said that it has raised $21M in an equity funding, AllianceBernstein L.P., ARCH Venture Partners, GF Private Equity Group, Intel Corporation, Madrona Venture Group, Mobius Venture Capital and Polaris Venture Partners, which will help it expand sales, marketing, product development and manufacturing operations. The company said the funding would "fulfill the company's capital needs" for the "foreseeable future", which is why it has withdrawn its IPO filing. The company said in that release that it intends to resubmit a registration station, albeit under the new, streamlined process of the JOBS Act.