a variable gain amplifier includes at least two amplifiers for amplifying a signal , the at least two amplifiers being connected in series with one another , and a variable resistor having a resistance that is controlled in accordance with a voltage applied to a control terminal , the variable resistor being connected between the outputs of two of the at least two amplifiers having opposite output phases . as a result , the variable gain amplifier is capable of a low - gain operation and an attenuating operation in a high - frequency amplifier used in a communications device for transmitting and receiving high - frequency signals .