A low power low noise amplifier employing negative feedback and current reuse techniques

• A 1.3 mW, inductorless differential Common Gate Low Noise Amplifier is presented in this paper.
• The idea is to remove the stringent trade-off between the input matching and power consumption by using the transconductance of the tail transistor.
• Unlike gm-boosting, the proposed technique doesn’t degrade the linearity.
• The circuit is low power, low active area and wideband, so it’s suitable for multimode and Wireless Sensor Network applications.

This paper presents a low power wideband differential Low Noise Amplifier (LNA) suited for multimode receivers and Wireless Sensor Networks (WSN) in a 0.18 μm CMOS technology. By using negative feedback, the stringent trade-off between the input matching and the transconductance (gm) is broken and the required transconductance of input transistor in Common-Gate (CG) LNA is decreased. As a result of this and also using the current reuse implementation scheme, power consumption (PDC) is significantly reduced. The circuit provides high gain and decreased Noise Figure (NF) in spite of low PDC. The LNA structure is fully inductorless, and the core circuit consumes only 1.3 mW from a 1.8-V supply occupying an area of 0.032 mm2. A maximum voltage gain of 20.1 dB is provided with 3 dB bandwidth up to 3.3 GHz. The input matching is better than −16 dB from 20 MHz to 3.3 GHz. The minimum NF is 3.2 dB with third order Input Intercept Point (IIP3) of −2.4 dBm.