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9. A 0.34THz Schottky Varactor Frequency Doubler with 50% PAE

Author

Hongji Zhou, Wei Kou, Shixiong Liang, Dong Yazhou, and Hongxin Zeng

Subjects
Materials science, business.industry, Terahertz radiation, Frequency multiplier, Bandwidth (signal processing), Schottky diode, law.invention, Power (physics), Maximum efficiency, law, Optoelectronics, business, Varicap, Waveguide
Abstract

This paper describes a 0.34THz Schottky varactor frequency doubler with 50% PAE. We focus on the design of frequency doubler input matching, using the single side heightening waveguide to reduce reflection and expand bandwidth The simulation results show that when the input power is 100 mW, the frequency doubler efficiency is more than 40% from 0.33 THz to 0.36 THz, the output power is more than 40 mW and the maximum efficiency is up to 50%.

Published
2021

10. Terahertz Frequency Doubler Based on Multi-anodes Monolithic Integrated GaAs Diode

Author

Wei Kou, Dong Yazhou, Hongji Zhou, Ziqiang Yang, and Shixiong Liang

Subjects
Materials science, business.industry, Terahertz radiation, Frequency multiplier, Optoelectronics, Substrate (electronics), business, Anode, Diode, Power (physics)
Abstract

This paper proposes two terahertz monolithic integrated doublers in the terahertz band (170 GHz, 340GHz), have been designed and fabricated on a 15μm thick GaAs film substrate. The front stage frequency multiplier adopts eight anodes and the rear stage adopts six anodes. Measurement has shown that the efficiency is greater than 20% in the frequency range of 157-177GHz (First stage) with the input power of 300mW, and the peak efficiency at 170GHz is 26.25%. The simulation showed efficiency is greater than 40% in the frequency range of 330-350GHz(Second stage) with the input power of 60mW, and the peak efficiency at 341GHz is 46%.

Published
2021

11. A Meta-Structure-Based Frequency Doubler With Low Input Power.

Author

Dong, Yazhou, Liang, Huajie, Liang, Shixiong, Kou, Wei, Hao, Xiaolin, Zhou, Hongji, Zeng, Hongxin, Feng, Zhihong, Yang, Ziqiang, and Zhang, Yaxin

Subjects
ELECTROMAGNETIC waves, ELECTRIC fields, SCHOTTKY barrier diodes, ELECTROMAGNETIC wave scattering, IMPEDANCE matching
Abstract

As the operating frequency increases, the output power of traditional frequency doublers becomes too low to drive the next stage devices. To address this problem, a double-layer meta-chip circuit consisting of a symmetrical split ring (SSR) structure with a doubler circuit is presented. It combines the transmission mode in the rectangular waveguide with the resonance mode in the meta structure. The meta structure improves the coupling efficiency between the diode and electromagnetic energy, strengthens the electric field at the diode, and ultimately enhances the efficiency of the frequency doubler at low input power. From 160–180 GHz, the experiments show that the frequency doubler with SSR achieved a peak efficiency of 22.4% with an output power of 10.6 mW. Its performance of maximum output power is 45.2% better than the traditional structure, which provides an important technical approach to achieve higher efficiency at low input power. [ABSTRACT FROM AUTHOR]

Published
2022
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14. All-Polarized Wideband Rectenna With Enhanced Efficiency Within Wide Input Power and Load Ranges.

Author

Bo, Shao Fei, Ou, Jun-Hui, Dong, Yazhou, Dong, Shi-Wei, and Zhang, Xiu Yin

Subjects
ELECTRIC current rectifiers, BREWSTER'S angle, TELECOMMUNICATION satellites, RECEIVING antennas, WIRELESS power transmission, POWER density
Abstract

The efficiency of a rectenna varies under the influences of receiving polarization tilt angle, operating frequency, input power, and load value in different applications. Yet, no reported rectenna can realize stable efficiency when all these factors vary within a wide range. To solve this problem, an all-polarized rectenna is proposed in this article, composed of a dual-input rectifier and a dual-polarized (DP) antenna. By introducing a novel six-port coupler, the rectifier maintains stable efficiency at wideband, wide input power, and dc load ranges. Moreover, the efficiency of the rectifier keeps stable when the antenna receives power at different polarization tilt angles. Accordingly, a DP antenna with extended bandwidth and 3-dB beamwidth is implemented. Finally, the rectenna is formed. The prototype can maintain beyond 70% of the peak efficiency from 1.7 to 2.5 GHz. At a power density as low as 1 μW/cm2, efficiency can reach 24.4%. Furtherly, the rectenna is demonstrated by forming a battery-less digital clock. The clock can be powered wirelessly by a WiFi router or cellular base station with maximum distances of 1 or 70 m respectively. Besides, the clock can successfully function under significant transmitting-direction deviation or polarization misalignment between the power source and the rectenna. [ABSTRACT FROM AUTHOR]

Published
2022
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23. Highly-Isolated RF Power and Information Receiving System Based on Dual-Band Dual-Circular-Polarized Shared-Aperture Antenna.

Author

Ou, Jun-Hui, Xu, Bihang, Bo, Shao Fei, Dong, Yazhou, Dong, Shi-Wei, Tang, Jie, and Zhang, Xiu Yin

Subjects
REFLECTOR antennas, ANTENNAS (Electronics), INFORMATION storage & retrieval systems, APERTURE antennas, ELECTRIC current rectifiers, POWER transmission, RECEIVING antennas
Abstract

A highly integrated RF power and information receiving system is proposed in this paper. The system consists of an antenna, a rectifier, and an information receiving module. The information receiving module acts as part of the dc load. To realize high integration, a dual-band, dual-circular-polarized shared- aperture antenna is implemented. The antenna consists of a left-circular-polarized element operating at 2.4-GHz band, and a high-gain, right-circular-polarized $2\times 2$ array operating at 5.8-GHz band. The lower-frequency antenna is for communication, while the higher-frequency one is for power transmission. All the elements share the same aperture, and the radiator of lower- frequency antenna acts as the reflector of higher-frequency elements. Accordingly, a class-F rectifier that matches the higher- frequency array is designed and verified, and a system-level demonstration is implemented. Owing to the high isolation on frequency splitting and polarization diversity, the baseband signal can be successfully demodulated under a 30-dB input-power-level difference at two frequency bands. The base-band information can be displayed by an ink screen. The received RF power can be effectively rectified and power the data-processing modules. [ABSTRACT FROM AUTHOR]

Published
2022
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36. Noncontact Measurement of Complex Permittivity of Electrically Small Samples at Microwave Frequencies.

Author

Dong, Jing, Shen, Fazhong, Dong, Yazhou, Wang, Ying, Fu, Wenli, Li, Huan, Ye, Dexin, Zhang, Bin, Huangfu, Jiangtao, Qiao, Shan, Sun, Yongzhi, Li, Changzhi, and Ran, Lixin

Subjects
PERMITTIVITY, RAYLEIGH model, HOUGH transforms, MIMO systems, SIGNAL processing
Abstract

Noncontact measurements of material parameters have important applications in various fields. In this paper, we propose a noncontact measurement of complex permittivity for electrically small samples at microwave frequencies. Based on Rayleigh approximation, we propose a noncontact measurement approach that can linearly retrieve complex permittivity from the measured impedance change. Using a subwavelength resonance, far-field radiation can be effectively suppressed, and thus the measurement is not notably influenced by unwanted environmental reflection. With the features of simple calibration and noncontact measurement, our method can be widely used in repeated on-site measurements of complex permittivity for small-sized samples at microwave frequencies. [ABSTRACT FROM AUTHOR]

Published
2016
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43. Radio Frequency Beamforming Based on a Complex Domain Frontend.

Author

Peng, Zhengyu, Chen, Jialong, Dong, Yazhou, Zhang, Bin, Qiao, Shan, Ye, Dexin, Huangfu, Jiangtao, Sun, Yongzhi, Li, Changzhi, and Ran, Lixin

Subjects
RADIO frequency, ENERGY consumption, BROADBAND communication systems, BEAMFORMING, COST effectiveness
Abstract

The state-of-the-art phased array-based digital beamforming systems suffer from disadvantages of high power consumption, high cost, and system complexity due to the massive use of transmitter/receiver (T/R) modules and high-speed digital and digital–analog mixed devices. In this paper, we point out that by proposing a new concept “complex domain” radio frequency (RF) frontend, the relatively slowly changed waveform delay information required to accomplish adaptive beamforming can be separated from wideband RF signals, based on which a self-contained beamforming system can be implemented with a low-speed baseband. By introducing vector RF multipliers in the proposed frontend, the amplitude and phase of RF signals can be simultaneously controlled by the real and imaginary parts of complex numbers, such that beamforming algorithms derived in complex domain can be directly applied without any form of transformation. By doing so, the massive use of conventional T/R modules and high-speed baseband devices can be avoided. Theoretical analysis and experimental demonstration based on commercial components have validated the proposed approach. Our method is able to significantly simplify the realization and decrease the cost of wideband digital beamforming systems, and can be widely used in low cost, power efficient beamforming applications. [ABSTRACT FROM AUTHOR]

Published
2016
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