We present in this paper a wideband RF demodulator using a five-port correlator and a power detector for channel sounding applications. The demodulator has been fabricated using microstrip components. The correlator r...We present in this paper a wideband RF demodulator using a five-port correlator and a power detector for channel sounding applications. The demodulator has been fabricated using microstrip components. The correlator receives from the five-port qualities that allow it to be low-cost and less sensitive to the phase and amplitude imbalances. A calibration procedure is proposed to find the complex envelope of the RF signal applied at the input of the five-port correlator. Simulation with Advanced Design System software and measurement results have been conducted to demonstrate its capabilities as a RF signal demodulator operating in a wideband around 2.4 GHz frequency.展开更多
热带地区云的覆盖率高,卫星辐射资料特别是红外通道的数值模拟容易受到云的影响,提高台风等热带天气系统卫星亮温资料的模拟能力,有助于热带地区数值模式的检验以及提高卫星资料直接同化的水平。首先,利用天气研究和预报模式（Weather R...热带地区云的覆盖率高,卫星辐射资料特别是红外通道的数值模拟容易受到云的影响,提高台风等热带天气系统卫星亮温资料的模拟能力,有助于热带地区数值模式的检验以及提高卫星资料直接同化的水平。首先,利用天气研究和预报模式（Weather Research and Forecasting Model,简称WRF）对＂＂珍珠＂＂台风的三维气象场,包括云结构特征,进行了模拟,并诊断分析了总云量、云顶气压等物理量;然后,结合快速辐射传输模式（fast ra-diative transfer model for TOVS,简称RTTOV）8.7版对＂＂珍珠＂＂台风的高分辨率红外辐射探测仪3型（HighResolution Infrared Radiation Sounder,简称HIRS/3）红外辐射亮温进行了模拟,并且比较了有云和无云条件下的模拟结果。结果表明,如果不考虑云的影响,RTTOV模式无法模拟出台风的结构特征;结合三维云特征的模拟量,RTTOV模式可以较好地模拟出HIRS/3第4-10、13-19通道的辐射亮温。加入云结构特征对峰值能量高度在云层以下的红外通道的模拟有正面影响,该方案既可以作为检验模式模拟的一种手段,同时也表明红外资料在热带天气系统的资料同化领域具有潜在的应用能力。展开更多
In this article, we present multiple-input receiver architecture for MIMO (Multiple-Input Multiple-Output) wireless communication applications. The proposed implementation is provided by a defined number of identical ...In this article, we present multiple-input receiver architecture for MIMO (Multiple-Input Multiple-Output) wireless communication applications. The proposed implementation is provided by a defined number of identical receiver units that are fed by a RF modulated signal on specific carrier frequency, power strength and initial phase. These units carry out the corresponding amplification, filtering and demodulation procedures. Details on design and implementation of this Printed-Circuit-Board are introduced and further discussed. Experimental results are also presented, allowing the validation of investigation on the performance of the current receiver architecture. Besides, these measurements indicate that the proposed device, combining with a suitable antenna array, provides a versatile receiver platform for baseband signal processing. The incoming RF modulated signals have frequencies on the range of 2.4 GHz, several phases, magnitudes and modulation modes. From these, it seems that the proposed receiver implementation supports MIMO communication and multiple port channel characterization applications at 2.4 GHz ISM (Industrial, Scientific and Medical) band.展开更多
文摘We present in this paper a wideband RF demodulator using a five-port correlator and a power detector for channel sounding applications. The demodulator has been fabricated using microstrip components. The correlator receives from the five-port qualities that allow it to be low-cost and less sensitive to the phase and amplitude imbalances. A calibration procedure is proposed to find the complex envelope of the RF signal applied at the input of the five-port correlator. Simulation with Advanced Design System software and measurement results have been conducted to demonstrate its capabilities as a RF signal demodulator operating in a wideband around 2.4 GHz frequency.
文摘热带地区云的覆盖率高,卫星辐射资料特别是红外通道的数值模拟容易受到云的影响,提高台风等热带天气系统卫星亮温资料的模拟能力,有助于热带地区数值模式的检验以及提高卫星资料直接同化的水平。首先,利用天气研究和预报模式（Weather Research and Forecasting Model,简称WRF）对＂＂珍珠＂＂台风的三维气象场,包括云结构特征,进行了模拟,并诊断分析了总云量、云顶气压等物理量;然后,结合快速辐射传输模式（fast ra-diative transfer model for TOVS,简称RTTOV）8.7版对＂＂珍珠＂＂台风的高分辨率红外辐射探测仪3型（HighResolution Infrared Radiation Sounder,简称HIRS/3）红外辐射亮温进行了模拟,并且比较了有云和无云条件下的模拟结果。结果表明,如果不考虑云的影响,RTTOV模式无法模拟出台风的结构特征;结合三维云特征的模拟量,RTTOV模式可以较好地模拟出HIRS/3第4-10、13-19通道的辐射亮温。加入云结构特征对峰值能量高度在云层以下的红外通道的模拟有正面影响,该方案既可以作为检验模式模拟的一种手段,同时也表明红外资料在热带天气系统的资料同化领域具有潜在的应用能力。
文摘In this article, we present multiple-input receiver architecture for MIMO (Multiple-Input Multiple-Output) wireless communication applications. The proposed implementation is provided by a defined number of identical receiver units that are fed by a RF modulated signal on specific carrier frequency, power strength and initial phase. These units carry out the corresponding amplification, filtering and demodulation procedures. Details on design and implementation of this Printed-Circuit-Board are introduced and further discussed. Experimental results are also presented, allowing the validation of investigation on the performance of the current receiver architecture. Besides, these measurements indicate that the proposed device, combining with a suitable antenna array, provides a versatile receiver platform for baseband signal processing. The incoming RF modulated signals have frequencies on the range of 2.4 GHz, several phases, magnitudes and modulation modes. From these, it seems that the proposed receiver implementation supports MIMO communication and multiple port channel characterization applications at 2.4 GHz ISM (Industrial, Scientific and Medical) band.
