One of the most important things in designing modern telecommunication systems is the need to increase data transfer speeds. Increasing the transmission speed requires a wider bandwidth and work in a higher frequency range, and this has led to more attention to broadband circuits. For applications with a bit rate of 40 Gb/s, the bandwidth required for the amplifier is 28GHz. For this purpose, in this paper, 30GHz broadband amplifiers are designed. In this paper, 5 amplifiers with distributed cascade pseudo-differential topology with cascade classes of 2 to 6 stages in which there is only one gain cell in each floor are designed. The proposed circuits were implemented in RF_CMOS 0.18 µm technology and simulated in ADS software. The compromise of the parameters is in favor of the 4-stage amplifier. In this amplifier, the voltage gain in the 30GHz bandwidth is 25dB, while other scattering parameters are below 10dB. Power consumption is 162mW and chip area is 0.74mm2 and noise figure is 5dB, which are good results compared to other designs.