Guerilla RF, a startup wireless infrastructure company that recently secured $800,000 in funding from the Piedmont Angel Network and others, will get a chance to impress more investors at the CED Tech Venture Conference in Raleigh in September. Guerilla RF was founded in 2013 by Ryan Pratt, and it designs chips for use in "small cells" or "carrier class Wi-Fi," that mobile carriers are able to use to increase network capacity without large new towers. Pratt's engineering resume includes…