This letter proposes an integrated rectifying-mixer (IRM) circuit designed for simultaneous wireless information and power transfer (SWIPT) receiver architecture. The advantage of IRM is that it combines the functions of rectifier and mixer. When used in the SWIPT receiver, it can process information and power simultaneously, greatly improving the integration of SWIPT receiver and communication anti-interference capabilities. To validate the design, the IRM is subject to both 5.8-GHz high-power RF signal and 5.68-GHz low-power local oscillator (LO) signal. The measurements show that the maximum power conversion efficiency (PCE) is 51.25% for quadrature phase shift keying (QPSK) (17-dBm RF input) signal, 47.99% for binary phase shift keying (BPSK) (17-dBm RF input) signal, 61.7% for continuous wave (CW) signal (21-dBm RF input), and the conversion loss (CL) is 18.2 dB. In addition, the communication function of IRM is validated by measuring the error vector magnitude (EVM), proving that the IRM circuit is suitable for SWIPT systems.

In this paper, a novel microwave oscillator incorporating miniaturized nested split-ring resonators is proposed. The high-quality (Q) factor and wide spurious-free band of the NSRR contribute to low-phase noise and high-harmonic suppression of the proposed oscillator circuits. In addition, the NSRR is featured by compact size of 0.12λ_g × 0.12λ_g, where λ_g is the guided wavelength of resonance frequency. The fabricated 2.4 GHz oscillator has an output power of 11.7 dBm with 5 V DC supply and 10 mA current consumption. The second harmonic suppression is −45.49 dBc, the phase noise is −110 dBc/Hz @100 kHz, and the DC–RF conversion efficiency is measured as 30%.

This letter proposes a novel wideband 360° filtering phase shifter (FPS), which combines a reflection-type phase shifter (RTPS) and two switch-type phase shifters (STPSs). The RTPS is based on a filtering magic-T configuration with varactor diodes on the collinear ports, which simultaneously realizes the filtering function and 0°–90° phase shift. Then, a 180° STPS and a 90° STPS are cascaded with the RTPS to form the proposed wideband 360° FPS. It achieves a full 360° continuous phase shift and good frequency selectivity within a wide passband. For demonstration, a prototype of the proposed wideband 360° FPS was fabricated and measured. The measured results show that the prototype operates over a 2–3-GHz bandwidth with a 40% fractional bandwidth (FBW), exhibiting a maximum in-band phase error of ±6.14°, a root-mean-square (rms) phase error of 3.55°, and a return loss (RL) better than 10 dB.

This paper presents a high-efficiency and integrated millimeter-wave rectenna, which aims to provide stable wireless power supply for small wireless sensor networks in Internet of Things (IoT) environments. The antenna adopts slot-coupled feeding, with the feed line and the radiating patch located on opposite sides of the ground plane, it can effectively reduce the interference between the antenna and circuitry and increase the effective radiating area. Two Schottky diode are symmetric parallel mounted in rectifier, which can reduce the power losses caused by the junction resistance, and improve the power conversion efficiency (PCE). The measurement results show that the rectenna has achieved a maximum gain of 19.2 dBi, and PCE of 66.1% with 188 Ω load at 21 dBm input power. Additionally, by using the tiled stacking technique, a DC-DC power management module, a Bluetooth transmitting module and temperature, humidity, and light sensors were integrated with the rectenna to construct a highly integrated millimeter-wave power receiver with dimensions of only 32×32×10 mm ³ . This receiver can stably receive RF power from external wireless power source and drive the sensors and information transmitter module to return data in real-time, achieving simultaneous wireless power and information transfer (SWIPT), which demonstrate significant application potential in IoT scenarios.