Shiwei Dong

60 GHz low loss, amplitude and phase balanced radial waveguide power combiner

This paper presents a 60 GHz low loss, amplitude and phase balanced radial waveguide power combiner using a structure easy to manufacture and assembly. At V band 58∼63 GHz, the return loss at each port of the radial waveguide power combiner is below −20dB, the insert loss from input port to output port is below 0.2 dB. The differences of amplitude and phase between input ports are within 0.2dB and 0.5°respectively. The simulated results show that the radial waveguide power combiner is well satisfied for high frequency and high efficiency power combining.

CW terahertz source techniques for space systems

Many terahertz systems have been put forward and some of them even find space application. Continuous-wave (CW) terahertz sources will play an important role in space systems. Many CW terahertz techniques have been realized in laboratory and even employed. Those proper must be pre elected for space systems with strict limitation. Some space terahertz applications are introduced and CW terahertz sources compared. Among them prospective source technology for space are stressed.

A new solar power satellite system faced to engineering: Concentric disc

To release pressure of solar power satellite engineering, a concentric disc system model is put forward here. Classical Sandwich structure is abandoned for different requirement for planar accuracy between solar array and microwave power transmission array. The solar array is mounted with solar cell on both sides to reduce the system power dynamic range. The microwave power transmission disc circumrotates to maintain a perfect plane. Such a system can operate at increasing power level during its construction.

A design of K band E-plane folded magic tee matched in two ways for spatial power combining

Magic tee is widely used in microwave systems; the four arms of conventional magic tee direct at four different directions, which give inconvenience to the assemblage of a system. In this paper, An E-plane folded magic tee is presented. The designed E-plane folded magic tee for spatial power combining is analyzed in HFSS, and the result is also presented here. For the convenience of assemblage, the magic tee is designed with port 2 and port 3 folded in E-plane in the same direction. If the magic tee works as power combiner and splitter, the power amplifier units can locate at the same side. So the folded structure of magic tee plays an important role in downsizing the microwave system and reducing the system weight.

High efficiency power combining of K band TWTAs for space communications

This paper presents a high efficiency power combining demonstration of two 100 W K-band TWTAs using a 4-port magic-T hybrid junction-based waveguide circuit. A low loss, amplitude and phase balanced, high power magic-T is designed for power combiner. Power combining efficiencies of greater than 90% and output power of more than 170W over a 0.6 GHz frequency band are successfully demonstrated. Such hybrid junctions can also be considered as elements within a corporate combining architecture for much higher power generating.

High efficiency GaN Class E power amplifier at 5.8GHz with harmonic control network

This paper presents a 5.8GHz high efficiency class-E power amplifier (PA) using a 25-W GaN HEMT large signal model for wireless power transmission applications. The input and output harmonic control networks using λ/4 open-stub transmission lines is employed to obtain high output power and high efficiency. The simulation results show that the power-added efficiency (PAE) of 69% with a gain of 12.2dB and output power of 41.2dBm is achieved at 5.8GHz. The PAE over 63% and the output power over 40 dBm are maintained in 100 MHz bandwidth.

Calibration method of retrodirective antenna array for microwave power transmission

This paper presents a calibration method used to compensate channel amplitude and phase mismatch of the retrodirective antenna array for microwave power transmission. The calibration algorithm of N elements array antenna involves transmission of N time multiplexed orthogonal encoded signals. The received signals are coherently detected, accumulated in vector forms, and a set of correction factors are decoded from the received signal using the inverse of the encoded matrix. A Hadamard matrix is used as the encoding matrix. The demonstration of calibration method is carried out by simulation and analysis.

A 60 GHz solid-state power combining system

This paper presents a 60 GHz power combining system using an eight-way radial waveguide structure and four-way solid-state power combining modules. At 58~63 GHz, the return loss at each port of the radial waveguide power combiner is below -20dB, the insert loss is below 0.2 dB. The differences of amplitude and phase between input ports are within 0.2dB and 0.5° respectively. The return loss of the power combining module is below -10 dB and the loss in it is below 1.7 dB. The total power combining efficiency of the system is expected to be about 65%.

Spatial power combining in microwave power transmission systems

The solar power satellite (SPS) is potentially an important energy source in the future and many models have been investigated around the world. Microwave power transmission (MPT) is the pivotal technology of a SPS system. A large power generation and transmission panel is often considered with emphasis in MPT research. Two architectures may be to construct the space segment of the MPT system. For semiconductors scheme, active integrated antennas (AIAs) can be employed to construct such a panel with great advantages. Microwave power combination in open space is important to the MPT system and should be optimized. A 35GHz AIA array is presented for demonstration aim.

Advances of terahertz research and terahertz satellite communications

Remarkable progress has been made of terahertz technologies such as the source and detector. Great advancement has also been achieved of terahertz systems. Such progress reviewed here presents a big impetus to terahertz satellite communications. For satellite-to-satellite communications terahertz link shows great advantages over either millimeter-wave link or optical link. The architecture of terahertz satellite communication systems is proposed.