Laser diode matching circuit and method of impedance matching therefor

摘要

A laser diode is matched to a laser driver IC by a microwave stub to take advantage of radio frequency/microwave effects of electrical conductors on high frequency signals. The microwave stub is a piece of microwave transmission line with a characteristic impedance defined by its physical dimensions and its material. A transmission line having a distributed set of capacitors and inductors is tuned over a range of frequencies by changing its operating length/width. A capacitor short circuits the microwave stub to ground. The capacitor position along the microwave stub determines the microwave transmission line operating length (and hence frequency). Therefore, a matching network is tuned by changing the capacitor position along the microwave stub instead of using several different valued capacitors.