What is the result of increasing the Q of an impedance-matching circuit?

The Quality factor (Q) of a circuit is a measure of its selectivity. It is mathematically defined as the ratio of the resonant frequency to the bandwidth (Q = f / BW). Rearranging this formula shows that bandwidth is inversely proportional to Q (BW = f / Q). Because of this inverse relationship, increasing the Q of an impedance-matching circuit results in a narrower, or decreased, matching bandwidth. A high-Q circuit is highly selective and only passes a very narrow range of frequencies. Options suggesting the bandwidth increases or that harmonics increase are incorrect. Higher Q actually provides a sharper frequency response and better harmonic suppression.