A gain boosting method without noise-figure degradation by optimizing interstage matching in a cascode low-noise amplifier (LNA) with emitter-degeneration inductor is demonstrated at 5.2 GHz using 2-μm GaInP/GaAs HBT technology. A low-pass LC matching network is inserted in the interstage of a conventional cascode LNA with emitter-degeneration-inductor to enhance the gain with the same current consumption. The 2-μu GaInP/GaAs HBT LNA without interstage matching has 14-dB power gain and 2.37-dB noise figure at 5.2 GHz while the 2-μm GaInP/GaAs HBT LNA with interstage matching has 19.5-dB power gain and 2.22-dB noise figure at 5.2 GHz. The current consumption is 2.3 mA and voltage supply is 3.6 V.
- Emitter inductive degeneration
- GaInP/GaAs HBT