Low power, highly stable and wideband LNA for GNSS applications in SiGe technology

A low power wideband low noise amplifier (LNA) was designed and implemented in SiGe HBT technology. The measured noise figure is less than or equal to 1 dB in almost the entire L-band. The gain in the L-band is above 13 dB with a gain variation of 4 dB. Hence, it´s useful for present as well as future GNSS applications. A single supply of +5V is used. The active current consumption is 5 mA for a collector to emitter voltage of 3V. The stability of the design was tested using various simulations prior to actual implementation which greatly helped in preventing oscillations in the circuit. It is found to be unconditionally stable in the frequency range of 40 MHz to 40 GHz. The design consists of simple matching and DC bias networks making it small in size and cost-effective.