Ka-band MMIC LNA Design

In order to better adapt to the requirements of smaller noise and better performance in low-noise amplifiers in radio communications,this article simulates and designs a 35GHz broadband monolithic microwave integrated circuit (MMIC) low noise amplifier,by adopting InGaAs pseudo-crystal high electron mobility transistor (pHEMT) process model. The circuit uses a three-stage cascaded dual power supply structure. The front-stage amplifier circuit optimizes the noise figure while ensuring a good input and output standing wave ratio. The last two stages provide maximum gain matching, which guarantees the good noise figure, gain flatness and VSWR of the overall amplifier.In addition, the source negative feedback inductance and bias network circuit of each stage are optimized to achieve a broadband output and high gain under low noise. The simulation design shows that under the working conditions of gate and drain bias voltages of -0.5V and 3V, and current of 90mA respectively, the amplifier has a minimum noise figure of less than 2dB and a maximum gain of more than 20dB in the 25-45GHz band. At 35GHz, it has a minimum noise figure of 1.702dB, a maximum gain of 24.594dB, an input standing wave ratio of 2.236 and an output standing wave ratio of 1.122.The designed low-noise amplifier can be implemented in a broadband millimeter wave transceiver system.