A G-Band Packaged Amplified Noise Source Using SiGe BiCMOS 55-nm Technology

This article introduces the first BiCMOS SiGe technology-based packaged noise source (NS) operating in the G-band (140-220 GHz). An amplified p-n junction diode has been packaged and biased in avalanche mode to generate excess noise ratios (ENRs(av)) of approximately 25 dB between 140 and 170 GHz at package output for an unbiased low state and a high state corresponding to a 20-mA cathode current. The two-stage amplifier is a cascode cell composed of two BiCMOS 55-nm NPN very high speed (NPNVHS) transistors with an emitter length and a width of 5.56 and 0.2 mu m, respectively. An optimal biasing results in a 8.2-mA current consumption for one cascode stage and an overall available power gain (G(av)) better than 12 dB between 140 and 180 GHz. This supports operation in a low state, where the diode is unbiased and the amplifier is biased, which constitutes a scheme that easily validates the minimum detectable signal (MDS) condition while exhibiting a 14-dB ENRav level in the beginning of G-band compared to this polarized low state. This NS shows a monitorable P-COLD and is adaptable to several noise receivers. In addition, the ENRav level flatness is better than 3 dB over the entire frequency range, and the impedance matching, better than -7.5 dB at package output, is not dependent on the NS bias condition. Noise figure (NF) extraction of a WR05-connectorized III-V amplifier [MPA04-1 from Virginia Diodes, Inc. (VDI)] was performed and compared to the ELVA ISSN-05 commercial NS measurement, showing low discrepancy. The same study was performed on-wafer for an NPNVHS transistor on BiCMOS 55-nm technology, showing a maximum discrepancy of 0.8 dB between the two measured NFs. The NF measurement accuracy of the MPA04-1 amplifier was assessed up to 220 GHz, by varying the chosen high state while keeping the low state completely unbiased. A maximum 0.5-dB variation over 12 obtained NF values is observed up to 200 GHz.