A design of LNA and RFVGA with broadband and wide dynamic gain range for digital video broadcasting application

Abstract

ABSTRACTA low noise amplifier (LNA) and a radio frequency variable gain amplifier (RFVGA) were designed for digital video broadcasting‐satellite second edition (DVB‐S2) receiver tuner integrated circuit using a CMOS 0.18‐μm process. To achieve broadband and dynamic gain range characteristics, a switching filter technique was modified and applied to the LNA. An RFVGA was designed using Gilbert cell topology to achieve the wide dynamic gain range. In addition to the LNA and RFVGA, two 15 dB attenuators were designed and placed in front of the LNA, which can be separated into three voltage gain modes, such as −15 dB, 0 dB, and 15 dB, according to the strength of the input signal power. Good noise performance was achieved in high‐gain mode, and high linearity characteristics were achieved in low‐gain mode. The designed CMOS LNA and RFVGA achieved a 50 dB gain dynamic range, a noise figure below 5.1 dB, an input third‐order intercept point of 13.08 dBm, and an input second‐order intercept point of 24.98 dBm at −15 dB voltage gain with a layout size of the total chip area of 1500 × 600 μm2. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:418–423, 2016