Design Optimization of Single-/Dual-Band FET LNAs Using Noise Transformation Matrix

This paper describes the design optimization of single- and dual-band inductively source degenerated field-effect transistor low-noise amplifiers (LNAs) using an analytical formula of noise parameters derived through a noise transformation matrix. The dual-band LNA design can be directly expanded from the single-band LNA design using a noise transformation matrix. The derived noise formulas of LNAs reveal that a simultaneous noise and input match (SNIM) can be obtained at a single frequency for a single-band LNA. For a concurrent dual-band LNA, the simultaneous noise match cannot be achieved at two different operating frequencies and thus a balanced design in noise performance is developed using a noise transformation matrix. This paper demonstrates a 5-GHz single-band and a 2.4/5-GHz concurrent dual-band two-stage single-voltage-supply LNA using 0.15- μm depletion-mode pseudomorphic HEMT technology to verify design methodology. The inductively source-degenerated common-source amplifier is applied at the input stage. The 5-GHz common-source common-drain (CS-CD) LNA shows 1.4-dB noise figure (NF) with an SNIM. Moreover, the 2.4/5-GHz CS-CD concurrent dual-band LNA has a balanced noise performance of 2.2-dB NF at 2.4 GHz and 2.0-dB NF at 5 GHz, respectively.