Characterization of wideband low-noise distributed amplifiers in 0.15 μm Gallium arsenide process

Two wideband low-noise distributed amplifiers implemented in 0.15 μm gallium arsenide process with alternative layout strategies is investigated. Simple common-source transistors are used in each of the four stages to explore compact layout techniques and its effect on the performance of the amplifier. In the first design, conventional layout is followed, while the core area of the second design is made compact by sharing the sources of the transistors in the consecutive stages. The measured small signal gain of the amplifiers are approx. 10.5 dB with a gain flatness of ± 0.5 dB. The bandwidth of the first design is 45 GHz and 36 GHz for the second amplifier. The measured NF for both the designs are better than 3 dB across most of the band and the measured saturated power is better than 15 dBm at a nominal bias. The area of the amplifiers are 1.3 mm2 and 1.15 mm2, respectively, including the pads.