A Novel Integrated Power Detection Circuit for Low Noise Amplifiers in Cellular Applications

A novel power sensing method, integrated in low noise amplifier architectures is presented and demonstrated in 130 nm SiGe BiCMOS technology. The power sensor architecture can be utilized to detect blocking signals by supply current variations caused from different amplifier saturation states. Therefore the combined amplifier/power sensor architecture overcomes the need of additional components in the RF signal path for input power sensing. Two sensor architectures are compared while one is implemented. The architectures ability to indicate input power by amplifier saturation is proven by measurement. It is shown that the sensor gives direct feedback at early stages before the amplifier is in full saturation. The amplifier achieves a maximum gain of 14.31 dB and is optimized for the 5G low-band frequency range from 600 MHz to 1 GHz.