SEMICONDUCTOR DEVICE AND AMPLIFIER

摘要

PROBLEM TO BE SOLVED: To increase the isolation between the input-output pads of a plurality of semiconductor elements having opposite inputting-outputting directions by arranging the elements in parallel on a semiconductor substrate and providing a plurality of grounding lines between the elements. SOLUTION: An HBT(heterojunction bipolar transistor) 15 for preceding stage and an HBT 18 for succeeding stage the inputting-outputting direction of which is opposite to that of the HBT 15 are arranged in parallel on a semiconductor substrate 1A. Then a plurality of grounding lines 21 are arranged between the HBTs 15 and 18. The signal inputted to the input pad 16 of the HBT 15 is amplified and the amplified signal is inputted to the HBT 18 from the output pad 17 of the HPT 15 through the input pad 19 of the HBT 18. Then the signal inputted to the HBT 18 is again amplified and the amplified signal is outputted from the output pad 20 of the HBT 18. Therefore, the oscillation which occurs in a closed loop can be suppressed.