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2024, 22(12):1313-1319.
DOI: 10.11805/TKYDA2024364
Abstract:
Terahertz communication has become a current research hotspot due to its extremely large bandwidth, and further improving the system capacity in terahertz systems has also become a problem worth exploring. This paper optimizes the terahertz system composed of all-electronic components using a hybrid Probability and Geometric Shaping(PGS) scheme. The Pairwise Optimization(PO) algorithm is employed to adjust the Probabilistically Shaped 16-ary Quadrature Amplitude Modulation(PS-16QAM) signal after probabilistic shaping to obtain the desired hybrid PGS-16QAM signal. By testing the optimization effects of PS-16QAM, Geometric Shaping(GS)-16QAM and PGS-16QAM on uniform 16QAM at different net rates, it is verified that the hybrid shaping has the best optimization effect. When the wireless transmission distance is set to 2 meters and the Normalized Generalized Mutual Information(NGMI) experimets have shown that threshold is set to 0.92, PGS-16QAM achieves a net transmission rate increase of 15.6%, 11.8%, and 3.8% compared to traditional 16QAM, PS-16QAM, and GS-16QAM, respectively.
Terahertz communication has become a current research hotspot due to its extremely large bandwidth, and further improving the system capacity in terahertz systems has also become a problem worth exploring. This paper optimizes the terahertz system composed of all-electronic components using a hybrid Probability and Geometric Shaping(PGS) scheme. The Pairwise Optimization(PO) algorithm is employed to adjust the Probabilistically Shaped 16-ary Quadrature Amplitude Modulation(PS-16QAM) signal after probabilistic shaping to obtain the desired hybrid PGS-16QAM signal. By testing the optimization effects of PS-16QAM, Geometric Shaping(GS)-16QAM and PGS-16QAM on uniform 16QAM at different net rates, it is verified that the hybrid shaping has the best optimization effect. When the wireless transmission distance is set to 2 meters and the Normalized Generalized Mutual Information(NGMI) experimets have shown that threshold is set to 0.92, PGS-16QAM achieves a net transmission rate increase of 15.6%, 11.8%, and 3.8% compared to traditional 16QAM, PS-16QAM, and GS-16QAM, respectively.
2024, 22(12):1320-1323.
DOI: 10.11805/TKYDA2024237
Abstract:
The demand for high-capacity, anti-interference, safe and reliable transmission between ships on the sea and between ships and aircraft is becoming urgent. Terahertz band has a high frequency band and large bandwidth, making it an excellent means of high-capacity transmission and anti-interference communication. Based on the characteristics of marine terahertz communication, the influence of water vapor attenuation on terahertz wave on the sea surface in China is analyzed firstly. Then, based on the link budget and propagation reliability calculation, a marine terahertz communication system is designed. After being tested on a 150 m river, the system's feasibility is verified by achieving a speed of 520 Mbps with an bit error rate of 2×10-8.
The demand for high-capacity, anti-interference, safe and reliable transmission between ships on the sea and between ships and aircraft is becoming urgent. Terahertz band has a high frequency band and large bandwidth, making it an excellent means of high-capacity transmission and anti-interference communication. Based on the characteristics of marine terahertz communication, the influence of water vapor attenuation on terahertz wave on the sea surface in China is analyzed firstly. Then, based on the link budget and propagation reliability calculation, a marine terahertz communication system is designed. After being tested on a 150 m river, the system's feasibility is verified by achieving a speed of 520 Mbps with an bit error rate of 2×10-8.
2024, 22(12):1324-1331.
DOI: 10.11805/TKYDA2024327
Abstract:
In order to meet the requirement of increasing transmission rate, the future communication technology will naturally develop to a higher carrier frequency, and terahertz communication technology becomes a possibility. Aiming at the I/Q imbalance problem in terahertz communication system under the background of large bandwidth, an I/Q imbalance damage model is constructed under terahertz zero-intermediate frequency architecture. The algorithm derivation and compensation architecture design are completed in corresponding narrowband and broadband scenarios, and the algorithm performance is improved by improving the cost function for broadband scenarios. The simulation results show that the Mean-Square Error(MSE) of the proposed algorithm is improved by 15 dB compared with that of the statistical algorithm. In the experiment of 220 GHz zero intermediate frequency communication system, the MSE of narrowband algorithm proposed in this paper is improved by 7 dB, and that of the broadband algorithm is improved by 1 dB.
In order to meet the requirement of increasing transmission rate, the future communication technology will naturally develop to a higher carrier frequency, and terahertz communication technology becomes a possibility. Aiming at the I/Q imbalance problem in terahertz communication system under the background of large bandwidth, an I/Q imbalance damage model is constructed under terahertz zero-intermediate frequency architecture. The algorithm derivation and compensation architecture design are completed in corresponding narrowband and broadband scenarios, and the algorithm performance is improved by improving the cost function for broadband scenarios. The simulation results show that the Mean-Square Error(MSE) of the proposed algorithm is improved by 15 dB compared with that of the statistical algorithm. In the experiment of 220 GHz zero intermediate frequency communication system, the MSE of narrowband algorithm proposed in this paper is improved by 7 dB, and that of the broadband algorithm is improved by 1 dB.
2024, 22(12):1332-1338.
DOI: 10.11805/TKYDA2024260
Abstract:
Traditional terahertz frequency doublers often utilize hybrid integrated circuits as implementation methods, leading to issues such as large size, high packaging loss, and poor stability. By employing an active device based on indium phosphide(InP) High Electron Mobility Transistors(HEMT) with a gate length of 2×25 μm, a fully monolithic integrated D-band frequency doubler is designed by using a combined simulation analysis method of Advanced Design System(ADS) and electromagnetic(EM) simulation. The frequency doubler is designed in the form of frequency doubling plus amplification, with the first stage being a frequency doubling circuit and the second stage using an amplification circuit. Within the range of 132~154 GHz, when the input power is 4.5 dBm, the output power is greater than 6 dBm, the fundamental wave suppression ratio is better than 31 dBc, the third harmonic suppression ratio is better than 36 dBc, and the maximum output power is 9 dBm@144 GHz, with a corresponding frequency conversion gain of 4.5 dB. The chip area of this frequency doubler is approximately 3.1 mm×1.3 mm. This design provides a new option for fully monolithic integrated terahertz sources and the realization of miniaturized terahertz sources.
Traditional terahertz frequency doublers often utilize hybrid integrated circuits as implementation methods, leading to issues such as large size, high packaging loss, and poor stability. By employing an active device based on indium phosphide(InP) High Electron Mobility Transistors(HEMT) with a gate length of 2×25 μm, a fully monolithic integrated D-band frequency doubler is designed by using a combined simulation analysis method of Advanced Design System(ADS) and electromagnetic(EM) simulation. The frequency doubler is designed in the form of frequency doubling plus amplification, with the first stage being a frequency doubling circuit and the second stage using an amplification circuit. Within the range of 132~154 GHz, when the input power is 4.5 dBm, the output power is greater than 6 dBm, the fundamental wave suppression ratio is better than 31 dBc, the third harmonic suppression ratio is better than 36 dBc, and the maximum output power is 9 dBm@144 GHz, with a corresponding frequency conversion gain of 4.5 dB. The chip area of this frequency doubler is approximately 3.1 mm×1.3 mm. This design provides a new option for fully monolithic integrated terahertz sources and the realization of miniaturized terahertz sources.
2024, 22(12):1339-1355.
DOI: 10.11805/TKYDA2024264
Abstract:
Terahertz waves occupy a unique position in the electromagnetic spectrum, characterized by high frequency, high bandwidth, and high penetration, which hold broad application prospects in fields such as communication, radar, imaging, sensing, and security inspection. Frequency converters like frequency multipliers and mixers are key components of solid-state terahertz systems. Schottky diodes boast low parasitic parameters, simple fabrication processes, and ease of integration, with their operating frequencies covering the entire terahertz band. Frequency conversion devices based on Schottky diodes, featuring room-temperature operation, broad bandwidth, electronic tunability, low phase noise, and high sensitivity, have become the mainstream devices in terahertz transceiver links. This article reviews the recent developments in Schottky diode technology, including its structure and fabrication methods. Additionally, it introduces the current state of frequency multipliers and mixers based on Schottky diodes and discusses future development trends.
Terahertz waves occupy a unique position in the electromagnetic spectrum, characterized by high frequency, high bandwidth, and high penetration, which hold broad application prospects in fields such as communication, radar, imaging, sensing, and security inspection. Frequency converters like frequency multipliers and mixers are key components of solid-state terahertz systems. Schottky diodes boast low parasitic parameters, simple fabrication processes, and ease of integration, with their operating frequencies covering the entire terahertz band. Frequency conversion devices based on Schottky diodes, featuring room-temperature operation, broad bandwidth, electronic tunability, low phase noise, and high sensitivity, have become the mainstream devices in terahertz transceiver links. This article reviews the recent developments in Schottky diode technology, including its structure and fabrication methods. Additionally, it introduces the current state of frequency multipliers and mixers based on Schottky diodes and discusses future development trends.
2024, 22(12):1356-1363.
DOI: 10.11805/TKYDA2024248
Abstract:
Terahertz communication is one of the important development directions for wireless mobile communication in the 6G era, characterized by large bandwidth and low latency, suitable for various application scenarios such as high-speed wireless backhaul and satellite communication. This paper designs a D-band (110~170 GHz) wireless communication system based on intermediate frequency synthesis, achieving D-band broadband wireless communication with a total bandwidth of (n×2) GHz by synthesizing n intermediate frequencies with a bandwidth of 2 GHz each, thereby achieving a transmission rate of over 100 Gbps. To verify the feasibility of the system, a 1/n scale-down verification was conducted on the designed n-path communication system. The results show that using a 2 GHz D-band channel bandwidth, a maximum of 11.2 Gbps air interface transmission rate and 9.4 Gbps service transmission rate can be achieved with 128-QAM(Quadrature Amplitude Modulation), proving that the n-path intermediate frequency synthesis system architecture using only one set of D-band RF front ends can achieve low-cost D-band broadband high-speed wireless communication.
Terahertz communication is one of the important development directions for wireless mobile communication in the 6G era, characterized by large bandwidth and low latency, suitable for various application scenarios such as high-speed wireless backhaul and satellite communication. This paper designs a D-band (110~170 GHz) wireless communication system based on intermediate frequency synthesis, achieving D-band broadband wireless communication with a total bandwidth of (n×2) GHz by synthesizing n intermediate frequencies with a bandwidth of 2 GHz each, thereby achieving a transmission rate of over 100 Gbps. To verify the feasibility of the system, a 1/n scale-down verification was conducted on the designed n-path communication system. The results show that using a 2 GHz D-band channel bandwidth, a maximum of 11.2 Gbps air interface transmission rate and 9.4 Gbps service transmission rate can be achieved with 128-QAM(Quadrature Amplitude Modulation), proving that the n-path intermediate frequency synthesis system architecture using only one set of D-band RF front ends can achieve low-cost D-band broadband high-speed wireless communication.
