Wideband Class AB Monolithic Power Amplifier

摘要

Wide-band power amplifiers are used in many electronic systems. In transmitters, for example, power amplification from the signal source to the output stage is conveniently realized with cascaded wide-band power amplifiers. In instrumentation applications there are many situations where high-frequency power amplification is required. Important characteristics of wide-band power amplifiers include the power output at 1-dB gain compression (P-1dB), the -3-dB small-signal bandwidth (f(-3dB), and the circuit power efficiency (ratio of signal power out to supply power in)). In general, input and output impendances matched to 50 or 75 Ohm are required. Other important considerations are circuit ruggedness, tolerance of input overdrive, fabrication, packaging cost, and the number and type of external components required. In this paper, a new monolithic power amplifier is described which achieves dc to 830-MHz small-signal bandwidth, 1-dB gain-compression power P (-1dB) equal to +20 dBm (100 mW) at 100 MHz, and requires no external components other than input and output coupling capacitors. The circuit has a small die size, is housed in an inexpensive package, and exhibits excellent tolerance to input overdrive. (reprints). (rh)