Michihiro Ide

This article presents a 256-element CMOS active phased-array transmitter (TX) that works at 19 GHz for low-Earth orbit (LEO) satellite applications. This work proposes a 90° coupler-end structure for circular polarization (CP) wave generation, which features low power consumption and enables dual-CP waves emitting in two directions. In addition, this work employs two calibration techniques to improve cross-polarization discrimination (XPD) in single-CP and dual-CP modes. The power consumption of the proposed structure is 9.4 W at 56-dBm average effective isotropic radiated power (EIRP), which is 40% lower than the state-of-the-art. It consumes 17.8 W at 64.7-dBm maximum EIRP. The beam-steering ability of this work can achieve ±65° with a sidelobe level <10-dBc. For the EVM measurement result, in single-CP mode, this work can support 256 amplitude-phase shift keying (APSK) modulation with a 2-Gbaud symbol rate on a 56-dBm EIRP output. In dual-CP mode, this work can support 256 APSK modulation with a 250-MBaud symbol rate on a 56-dBm EIRP output.

This work presents a D-band high-power-density four-element phased-array transceiver for 6G user equipment (UE). Conventional designs require large multi-stage LO generation circuits for D-band up/down conversion, making it difficult to achieve compact size and low-power consumption. To address this, we propose an integrated LO chain using an injection-locked tripling phase shifter (ILTPS), which enables both frequency tripling and phase shifting within a single circuit without multi-stage amplifiers. The ILTPS achieves an area of 0.088 mm² and a power consumption of 15 mW. In addition, to realize high power density, the transceiver integrates a bi-active sub-harmonic mixer (BA-SHM) and a D-band PA/LNA with PA-sharing TDD switching. An eight-element antenna-in-package (AiP) module using two transceiver ICs operates in the 142–164-GHz frequency range, achieving an EIRP of 25.7 dBm and a maximum data rate of 56 Gbps. The power consumption per element is 150 mW in TX mode and 93 mW in RX mode with 1 V VDD. The active area of this transceiver is 8.5 mm², and it is implemented using a 65 nm CMOS process.

This paper introduces an active reflector for D-band communication utilizing 122GHz wireless power transfer (WPT). The reflector consists of rectifiers with an integrated low-pass filter (LPF), an IF-band power combining network, and a 1-port amplifier composed of a circulator and IF-band amplifiers. The proposed rectifier not only works as an RF-DC converter but also operates as a self-heterodyne mixer by using the 122GHz WPT signal as a LO. Since the rectifier operates in a fully passive manner, it can simultaneously perform the upconversion and downconversion required for Tx and Rx operations. The IF signal obtained from downconversion is efficiently amplified and then re-input into the IF distributing network and rectifier after 1-port amplifier for upconversion and reflectively transmission in the specular direction. According to probe measurements, the rectifier achieves a power conversion efficiency (PCE) of 12.2% with an input power of 9.3dBm, and conversion gains of -15.9dB and -17.7dB for Tx and Rx modes, respectively. Additionally, the proposed rectifier supports a data rate of 48Gbps with a 64QAM modulation scheme and an 8GHz bandwidth for both Tx and Rx.

This letter introduces a 256-array wirelessly powered phased-array transceiver with 24-GHz wireless power transfer (WPT) for 28-GHz millimeter-wave 5G communication. The 256-element rectifier arrays are configured with discrete ICs, including GaAs diodes, baluns, DPDT switches, and digital ICs. The rectifier can convert a 24-GHz WPT signal to dc while providing the frequency conversion between 28-and 4-GHz IF signal by using a 24-GHz WPT as an LO signal. The phases of 4-GHz IF signals are changed by the 180 $^{\circ}$ phase shifters, configured with two baluns and a DPDT switch, resulting in Tx and Rx beamforming. According to the over-the-air (OTA) measurement with the 256-array prototype module, it can achieve 54% of PCE with 10-dBm input power and $-$ 19-dB conversion gain for Tx mode. The error vector magnitude (EVM) is also measured with the orthogonal frequency-division multiple access (OFDMA)-mode modulated signal, compliant with 5G new radio (NR), and the proposed transceiver can transmit and receive a 64 QAM modulated signal with 400-MHz bandwidth with 28-GHz beamforming.

This article presents a low-power 256-element $Ka$ -band CMOS phased-array receiver utilizing on-chip distributed radiation sensors for the low Earth orbit (LEO) small satellite communication system. Since the available solar cell area limits the power generation of the small LEO satellites, a distributed current-sharing common-gate (CG) low noise amplifier (LNA) and a voltage-tuning variable gain amplifier (VGA) are introduced to reduce power consumption. After utilizing the proposed technique, the power consumption of the beamformer is 2.95 mW/element. Moreover, the proposed voltage-tuning VGA is configured to utilize both upper and lower transistors for gain contributions to save power. The on-chip distributed radiation sensors are presented to eliminate the non-uniform radiation influence and realize 0.22-dB/Mrad gain degradation performance. The proposed receiver achieves $-$ 20-dBm single-element IIP3 with a 3.6-dB noise figure. The occupied on-chip area for a single element is only 0.24 mm $^2$ . DVB-S2X standard modulated signals of up to 256 amplitude and phase-shift keying (APSK) can be supported in the over-the-air (OTA) measurement. The receiver achieves $-$ 31.3-dB EVM and 24-Gb/s link speed under 1.5-GBaud dual-linear polarization signals. The measured 256-element beam pattern can cover radiated angle from $-$ 50 $^\circ$ to $+$ 50 $^\circ$ with lower than $-$ 9-dBc sidelobe level. Thanks to the proposed low-power distributed current-sharing CG LNA and on-chip radiation sensors, a low-power radiation-hardened phased-array receiver can be achieved for the small LEO satellites.

Lightweight and deployable phased arrays are important in Small-Satellite (Small-Sat) constellation systems to reduce price and increase link distance. This article proposes a Ka-band deployable active phased-array TX on a 4-layer liquid crystal polymer (LCP) board for a lightweight and high stowage rate solution to break through the trade-off between high antenna aperture size and small form factor in phased arrays. This article describes detailed designs of the phased array and its building blocks with the proposed 4-layer LCP substrate structure. Assembled with the beamformer ICs (BFIC), a Ka-band 8×4-element deployable active phased-array TX on the 4-layer LCP substrate is fabricated. The proposed deployable phased-array TX can steer the beam from -50° to 50°. The phased-array TX can drive 32-APSK DVB-S2 signal with a -28.7 dB EVM as well, revealing that the deployable phased-array TX performs with high phased-array performance. Furthermore, the TX achieved the lightest and thinnest phased array with 0.96 kg/m ² areal mass and 0.9 mm thickness. This groundbreaking research sets the stage for the realization of affordable and user-centric satellite communication (SATCOM) in low-earth orbit (LEO).

A $Ka$ -band 64-element deployable active phased-array transmitter (TX) on a hetero segment liquid crystal polymer (LCP) substrate for small satellites is proposed. The proposed phased-array TX achieved a large array size implementation and a small form factor with integrated six-layer and two-layer LCP substrates. Antenna and transmission line designs considering hetero layer structure are presented in detail. Achieving 46.7 dBm electronically isotropically radiated power (EIRP), the proposed phased-array TX can support 256-APSK DVB-S2X. As a result, the proposed deployable active phased-array TX successfully realizes low-launch cost with a 9.65 g lightweight and large antenna aperture size with superior EVM performance.

This article introduces a wirelessly powered phased-array transceiver for fifth-generation (5G) relay systems. To realize the battery-less relay operation, 24-GHz wireless power transfer (WPT) is employed. This relay transceiver consists of the proposed vector-summing backscatter for Transmitter (Tx) and a passive phase-shifting self-heterodyne Receiver (Rx) with a rectifier for Rx and WPT. The receiver generates dc power from the 24-GHz WPT signal, which is also used as a local oscillator (LO) signal to down-convert the 28-GHz 5G modulated data to a 4-GHz IF. The vector-summing backscatter up-converts the 4-GHz IF signal to 28-GHz using a 24-GHz LO signal while working as a 360° phase shifter with a 7-bit resolution. Both transmitter and receiver operate only using the generated power from the 24-GHz WPT. The chip area of the eight-path transceiver is 1.8 mm ² and the transceiver is mounted on a 32-element phased-array antenna board. This module generates 3.1-mW dc power from 6.7-mW/cm ² received power density at 24 GHz. The transmitter achieves a −2.2-dBm measured saturated equivalent isotropically radiated power (EIRP) and supports a −30° to +30° beam range. The measured error vector magnitude (EVM) values are −27.5 dB for Tx mode and −31.3 dB for Rx mode with a 400-MHz 64-QAM orthogonal frequency division multiple access (OFDMA)-mode signal (5G new radio (NR), MCS 19). The power consumption for each path is 0.03 mW in both Tx and Rx modes.