Temperature Calibrated K-Band Noise Source Employing a COTS Si-Ge HBT

In this paper a mm-Wave, temperature-calibrated K-band noise source built with commercial on-the-shelf (COTS) components is demonstrated. The proposed source includes a Si-Ge Heterojunction Bipolar Transistor (HBT) using its base-emitter (BE) junction driven into avalanche breakdown, as the main noise-generating element. Excess Noise Ratio (ENR) values reaching 10.8 dB were obtained with a 6.71 mA breakdown current, in a 24 GHz to 32 GHz bandwidth and a 21 °C to 102 °C device temperature excursion, with no impedance matching. A calibration model is also provided, which fits ENR magnitude with an average error less than 0.05 dB, when considering the maximum current and temperature ranges. An ENR drift error of 0.8 dB was instead reported for the uncalibrated source.