Room-Temperature Low-Noise Amplifier With 11-K Average Noise From 0.6 to 2 GHz

In this letter, a low-noise amplifier (LNA) with 11-K average noise in the frequency range from 0.6 to 2 GHz at
$+25 ^{\circ} \text{C}$
is designed, manufactured, and measured. The input matching network (IMN) of the amplifier is realized by a stepped high-impedance suspended substrate line structure that achieves input reflection coefficients lower than −10 dB over the whole frequency range. The LNA has an integrated temperature-stable noise calibration source for the system noise measurement. Furthermore, when the operating temperature drops to
$- 40\,\,^{\circ} \text{C}$
, the average noise of the LNA will decrease to 7.5 K. The LNA achieves good noise without the need for high-cost cryogenics, which will greatly reduce the cost of high-performance receiving systems for wide-band applications at low microwave frequencies.