While Fools should generally take the opinion of Wall Street with a grain of salt, it's not a bad idea to take a look at particularly stock-shaking analyst upgrades and downgrades -- just in case their reasoning behind the call makes sense.

What: Shares of RF Micro Devices, (NASDAQ: RFMD) gained 1% in premarket trading today after Bank of America upgraded the radio frequency solutions supplier from neutral to buy.

So what: Along with the downgrade, analyst Vivek Arya reiterated his price target of $10, representing about 40% worth of upside to Friday's close. While contrarians might be turned off by the stock's recent price surge, Arya thinks that there's plenty of room to run given the juicy market share and cost synergies RF Micro stands to gain from its proposed merger with TriQuint Semiconductor (TQNT.DL).

Now what: According to B of A, RF Micro's risk/reward trade-off is pretty attractive at this point. "We upgrade RFMD to Buy with $10 PO, or ~40% upside potential from current levels, as its proposed merger with TriQuint would bring together the #3 and #4 players in the radio frequency chip (RF) market to create a powerhouse with ~35% share," noted Arya. "RFMD's strong portfolio of power amps and switches combined with TriQuint's filters brings strong product, sales and cost synergies for 3G/4G smartphones, tablets and other connected devices. Also, ~25% exposure to high margin (55% GM, 30%+ OpM) and long life-cycle military/infrastructure adds defensiveness to the business model." Of course, with the stock already up about 45% in 2014, I'd wait for a wider margin of safety before buying into that bullishness.