In this letter, an efficient and compact tri-band rectifier with large frequency ratio is proposed, which adopts a novel low-cost direct current (dc)-pass filter structure in the design. Three large frequency ratio rectifiers are combined together by using diode arrays with a frequency-selective topology without additional impedance matching networks. The dc-pass filter is composed of microstrip line structures cascaded low-cost lumped components, which can effectively suppress the high-order harmonics at high-and low-frequency points while reducing the circuit size and costs of large frequency ratio. For validation, the proposed rectifier working at 0.915, 2.45, and 5.8 GHz is fabricated with the dimensions of 29.5 mm $\times$ 21.3 mm. The measured results show that the RF-dc power conversion efficiency (PCE) reaches 72.6%, 71.8%, and 73.5% at 0.915, 2.45, and 5.8 GHz, respectively, when the input power is 19 dBm. Compared with traditional multiband rectifiers, the proposed topology exhibits merits of compact size, high efficiency, and large frequency ratio.

This letter presents an efficient and compact ultrawideband (UWB) rectifier for wireless power transfer (WPT) and energy harvesting (EH) systems. The rectifier utilizes the voltage-doubling topology, which can effectively compress load impedance and facilitate broadband impedance matching. The input impedance matching network (IMN) is achieved using an L-type microstrip branch cascaded with a lumped inductor, which can counteract the capacitive of the diodes and reduce the circuit size. The proposed rectifier was designed and fabricated for verification with a 14.3 $\times$ 7.4 mm dimension. The measured results show that the rectifier can provide 197.6% (0.04–6.74 GHz) fractional bandwidth (FBW) with the power conversion efficiency (PCE) exceeding 50% and 196.8% (0.05–6.2 GHz) bandwidth with the PCE exceeding 60% at 22 dBm input power. The peak PCE reaches 74.8% at 1.9 GHz. Compared with traditional UWB rectifiers, the proposed one exhibits the merits of small size, high efficiency, and wider bandwidth.

A new design method of microwave monolithic integrated circuit (MMIC) predistortion linearizer compatible with the standard gallium arsenide (GaAs) high-electron-mobility transistor (HEMT) technology is proposed for wideband cancellation of power amplifier (PA)’s frequency-dependent amplitude-modulation (AM)/phase-modulation (PM) distortion. Adopting the dual-branch vector synthetic topology, a modified reflective topology is proposed to improve the extracted nonlinear signal with higher gain expansion dynamic range, and the reversed-biased HEMT-based varactor is deployed to realize variable phase tuning capacity. Phase and time-delay allocation between the linear and nonlinear branches is analyzed to achieve arbitrary monotone frequency-dependent phase predistortion performance. Four linearizer MMICs are designed and fabricated using a commercial 0.15- ${\mu}$ m GaAs HEMT process based on the proposed method and design procedure, in which the $X$ -and $Q$ -band chips are dedicated for positive phase conversion with the increase in input power, and the $Ku$ -and $K$ -band chips are for negative phase conversion. The $X$ -, $Ku$ -, and $Q$ -band designs are capable of exhibiting monotone increasing phase conversion with frequency, while the $K$ -band design exhibits monotone decreasing phase conversion with frequency. All these results are validated by on-chip measurement. Moreover, measurement conforms that consistent predistortion performance can be maintained by tuning the biasing voltage under different temperatures; static and dynamic measurements are performed with the designed linearizers applying to PA modules, validating the wideband cancellation capacity of frequency-dependent AM/PM distortion and the linearity improvement under wideband modulated signal excitation.

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.

This paper presents the balanced-to-balanced Gysel filtering power divider with arbitrary power division for first time. Based on the multicoupled series-resonator bandpass prototype network, a detailed theory analysis is presented and the corresponding design equations are concluded. Two filtering power dividers with the division ratio of 2 and 3 are realized using the half-wavelength resonator and the short-stub-loaded resonator. Finally, two example circuits are fabricated and measured for verification. The measured results show good agreement with the simulated and confirm the theory.

This letter describes efficient high-power rectifiers, using a cost-effective AlGaN/GaN Schottky barrier diode (SBD) with accurate extraction of large-signal parameters as the rectifying device. The thin-barrier (TB) recess-free GaN SBD exhibits a low turn-on voltage of 0.5 V, a low on-resistance of 6.2 $~\Omega $ , a low junction capacitance of 0.28 pF, and a high breakdown voltage of 66 V. A precise large-signal equivalent-circuit model is derived by elaborating the measured $I$ – $V$ , $C$ – $V$ data, and $S$ -parameters under different dc bias conditions. For model verification, two separate rectifiers working at 5.8 and 10 GHz are fabricated. The measured results indicate that, with 31-dBm input power, the maximum efficiencies of the two rectifiers are 78.9% and 76.6% at 5.8 and 10 GHz, respectively. The maximum power handling capability of each single SBD reaches 36 dBm. Owing to the low-cost high-performance GaN SBD with an accurate model, the high-power rectifiers exhibit the merits of compact size and high efficiency, indicating great potential for large-scale microwave power transfer (MPT) applications, such as space solar power systems (SSPS).