The nation’s small businesses can expect a wave of capital from a new generation of investors following the launch of a campaign to more than double the number of active angels backing UK firms by 2019.The new Become An Angel campaign, which will launch on Wednesday at the House of Commons, plans to recruit 23,000 new angels into the investor community, representing an extra £1bn-worth of growth capital.Today, 18,000 active angels invest an average of £47,000 each into early-stage UK businesses every year, according to the UK’s industry body for angels, the UKBAA. Become An Angel is the brainchild of …