Self-testing solution are very useful not only for make sure that devices are operating in the correct way, but also to realize system auto-calibration: auto-calibration is based on the experimentally extraction of proper parameters and it is usually realized by adopting radio frequency noise injection subsystems. In these cases, the systems use power acquisition devices, based on diode detectors, to perform the measurements; this solution denotes poor reconfigurability, unless a very complicated system architecture is adopted. In this paper we prove that the measurements needed for the over mentioned purpose, can be performed avoiding the application of complex architectures, by using software-defined radios with high level of potential reconfigurability and flexibility.

This contribution demonstrates, for the first time, on-chip Built-In Self Test (BIST) circuits based on avalanche noise diodes, a class of devices that are recently developed up to millimeter-waves in commercial Si technologies. The proposed BIST is constituted by a Low-Noise Amplifier (LNA) integrated with an avalanche p-i-n diode. The LNA has two equal channels that can be enabled independently. The first channel is connected to the input pads and, when active, the circuit operates as a standard LNA. The second channel, instead, is tied to the noise diode through a coupling capacitor and a 6-dB resistive attenuator. If the second channel is selected, the LNA works in self-test mode. As a consequence, the LNA gain and noise figure can be determined by switching on and off the integrated noise source and measuring the output noise power in these two conditions. The fabricated LNA (14.4-dB gain and 3.8-dB noise figure) is based on a 130-nm SiGe BiCMOS technology and operates between 20 and 30 GHz, i.e., in a frequency band compatible with 5G services. The integrated noise source (avalanche p-i-n diode with attenuator) has an Excess Noise Ratio (ENR) of about 17 dB at 30 GHz when biased with a 4 mA current. Experiments shows that measurements from the input pads (LNA mode) agree with those using the internal noise source (BIST mode) within 0.7 dB for gain and 1.3 dB for noise figure.

Avalanche noise diodes have recently been demonstrated in standard Si technologies such as CMOS and SiGe BiCMOS processes and used to design fully integrated noise sources. This letter investigates the reproducibility (die-to-die and run-to-run) and the stability over time of these devices. On-wafer noise sources are indeed relevant because of their extensive use in mm-wave noise measurements and for the calibration of high performance, single-chip receivers and radiometers. The results, obtained for the case study 30-GHz noise sources in 130-nm SiGe BiCMOS technology, show that a 0.3-dB reproducibility is achieved (ten dice fabricated in three different foundry runs) and that the generated noise has a stability of 0.07% in a period of 1000 min (Allan deviation of fractional temperature fluctuations). This will enable a new class of built-in test equipment (BITE) for terrestrial and space applications.

This paper investigates, for the first time, the feasibility of harmonic tag sensors based on orthogonally polarized waves. The main tag building blocks (circular and dual polarization antennas, Schottky diode frequency doubler and phase shifter) are designed, implemented with standard PCBs technology and materials, and experimentally characterized. Finally a proof-of-concept of the whole system operating at 1.04/2.08 GHz is proposed and validated in laboratory. The system can recover the encoded phase regardless the interrogation distance.

This paper proposes a Ka-band receiver front-end for future CubeSats Low-Earth Orbit (LEO) to Geostationary (GEO) inter-satellite links. The receiver is able to support very high data rates (up to 100 Mbit/s) in Quadrature Phase-Shift Keying (QPSK) when in the line of sight of a GEO satellite that is equipped with a steerable 70-cm antenna and transmitting a 25-W signal. The originality of the proposed approach is twofold. First we will demonstrate the receiver feasibility based on a class of miniaturized and low-cost microwave integrated circuits, currently available on the market. In particular, our receiver is based on a novel combination of integrated Low-Noise Amplifiers (LNA) with an image rejection filter, the latter exploiting the Substrate Integrated Waveguide (SIW) technology. An optimization of the via placement proved to be able to reduce the need for shielding apparatuses, thus simplifying the mechanics and reducing mass, volume and hardware costs. Secondly, we will propose a noise injection circuit capable of measuring and calibrating the receiver gain, also during in-orbit operation. Self testing capabilities are particularly relevant for CubeSats because the usage of commercial components poses serious reliability issues.