In this paper a novel 1-bit phase shifter topology based on dual input Low Noise Amplifier (LNA) for Active Reflective Intelligent Surfaces (Active RIS) is presented. The proposed solution is advantageous when the LNA has to be switched between two different radio-frequency (RF) sources. In particular, the Active RIS receiving (RX) patch antenna has two opposite feed points in order to obtain a 0° and 180° phase shifted signals entering the dual input LNA. A 1-bit digital enable (EN) signal is used to select one of the two inputs at a time, making the LNA behaves as pseudo-switch. Experiments were carried out on a fabricated prototype. The reported results show good agreement with simulations, thus validating the LNA operation. The LNA is based on a 130 nm SiGe BiCMOS technology, operating between 20 and 30 GHz with a 13 dB gain and 3 dB noise figure.

Solid-state noise sources are essential components in highly reliable mm-wave systems for life- or mission-critical applications such as self-driving car radars, airborne and satellite communication systems, space science instruments, and 6G to THz communications. Integrating a noise source, typically based on the avalanche effect of diode junctions, allows for testing of the architecture during production and operational lifetime. This paper presents a comparative study of three avalanche noise diodes integrated in different silicon technologies. The study is based on a solid experimental work that highlights the key points for a successful device design aimed at increasing the generated noise power, bandwidth, and operating frequency.

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 paper proposes a Low-Noise Block (LNB) downconverter operating in the Ku-band for Cubesat transponders. The frontend is composed by a Low-Noise Amplifier (LNA) and two switchable Substrate Integrated Waveguide (SIW) filters, providing a frequency reconfigurability to the system. The LNB is completed by a downconversion unit, constituted by a mixer, a PLL frequency synthesizer and an IF amplifier. A first breadboard features an overall gain of 54 dB with a 2.3 dB noise figure. The worst case linearity performance indicates an input-referred 1 dB compression point (P1dB) and a third-order intercept point (IIP3) equal to -27 dBm and -16 dBm respectively. This work is important since demonstrates a low-cost solution for satellite radio apparatuses based on commercial components and standard PCB.

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 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.

This paper presents a passive wireless harmonic transponder capable of transmitting information acquired by its vibration sensor. The system is equipped with a Schottky diode frequency doubler which converts the received signal from f ₀ to its second harmonic 2 f ₀. The sensed information is then encoded in the 2 f ₀ carrier phase using a varactor phase-shifter (acting as the phase modulator) biased through a piezoelectric transducer (which senses the mechanical vibrations). The transponder operation is demonstrated with particular focus on piezoelectric transducer vibrating resonance frequency. The side-band amplitude of the backscattered signal increases by about 10 dB for an increment of the acceleration of the mechanical system under test of 1.5 g 128 Hz.

This paper proposes a low-noise receiver frontend for nanosatellite and Cubesat platforms. The frontend is composed by a Low-Noise Amplifier (LNA) and two Substrate Integrated Waveguide (SIW) filters, providing a frequency reconfigurability to the system. The two filters operate in the 13 and in the 14 GHz uplink bands, and are selected by means of a pair of solid-state SPDT switches. As a results, 15.5 dB gain with 2.4 dB noise figure for the 13 GHz configuration and 17.8 dB gain with 2.3 dB noise figure for the 14 GHz configuration are obtained. This work is important since demonstrates a low-cost solution for satellite radio apparatuses based on commercial components on a standard PCB.