This paper presents a 60-GHz CMOS power amplifier (PA) with efficiency enhancement at power back-off. To boost the amplifier performance at millimeter-wave (mm Wave) frequencies, the neutralized amplifier stage is optimized with input transformer. Furthermore, the power combining techniques are used to enlarge the output power and enhance the efficiency at power back-off as well. The transformer-based power-combining PA consists of several unit amplifiers, operating in Class AB for both good back-off efficiency and linearity.
['Zhichao Li', 'Thangarasu Bharatha Kumar', 'Xiaopeng Yu', 'Kiat Seng Yeo']
A 60-GHz power amplifier with efficiency enhancement at power back-off