Design and Implementation of Multi-Frequency Digital Receiver Based on FPGA

2014 ◽  
Vol 643 ◽  
pp. 117-123
Author(s):  
Yu Peng Liu ◽  
Chao Du ◽  
Dong Lin Liu
Keyword(s):  
Digital Technology ◽  
Wide Band ◽  
Radar System ◽  
Center Frequency ◽  
Beam Forming ◽  
Digital Receiver ◽  
Effective Implementation ◽  
Great Performance ◽  
Implementation Method ◽  
Band Signal

Recently, the concept of software radar has been proposed. The wide application of the digital technology has become a trend. With the development of modern radar system, the system requires higher and higher performance to the radar receiver. The technology of digital receiver has become an effective implementation method for high-accuracy and wide-band radar receiving systems. However, most of the digital receiver can only receive one wide-band signal with one center frequency. A multi-frequency digital receiver which can receive several center frequencies of signal simultaneously [1] is discussed in this paper. We also describe the theory and the design about digital receiver, introduce digital downconversion (DDC), FIR and decimation, digital beam forming and channel calibration. Based on the research, a realization of multi-frequency digital receiver based on FPGA is put forward. The analysis and simulation is made and the result shows the design of great performance.

scholarly journals A procedure to correct the effects of a relative delay between the quadrature components of radar signals at base band

2005 ◽  
Vol 23 (1) ◽  
pp. 39-46
Author(s):  
◽  
La Hoz ◽  
◽  
Keyword(s):  
Radar Data ◽  
Center Frequency ◽  
Digital Receiver ◽  
The Real ◽  
Incoherent Scatter ◽  
Singular Region ◽  
Analysis Strategies ◽  
Relative Delay ◽  
Base Band ◽  
Band Signal

Abstract. The real and imaginary parts of baseband signals are obtained from a real narrow-band signal by quadrature mixing, i.e. by mixing with cosine and sine signals at the narrow band's selected center frequency. We address the consequences of a delay between the outputs of the quadrature mixer, which arise when digital samples of the quadrature baseband signals are not synchronised, i.e. when the real and imaginary components have been shifted by one or more samples with respect to each other. Through analytical considerations and simulations of such an error on different synthetic signals, we show how this error can be expected to afflict different measurements. In addition, we show the effect of the error on actual incoherent scatter radar data obtained by two different digital receiver systems used in parallel at the EISCAT Svalbard Radar (ESR). The analytical considerations indicate a procedure to correct the error, albeit with some limitations due to a small singular region. We demonstrate the correction procedure on actually afflicted data and compare the results to simultaneously acquired unafflicted data. We also discuss the possible data analysis strategies, including some that avoid dealing directly with the singular region mentioned above.

The NASA/GSFC 94 GHz Airborne Solid State Cloud Radar System (CRS)

2021 ◽  
Author(s):  
Matthew L. Walker McLinden ◽  
Lihua Li ◽  
Gerald M. Heymsfield ◽  
Michael Coon ◽  
Amber Emory
Keyword(s):  
Solid State ◽  
Digital Technology ◽  
Direct Relationship ◽  
Radar System ◽  
Digital Receiver ◽  
Internal Loop ◽  
Nasa Goddard Space ◽  
Cloud Radar ◽  
W Band ◽  
Reflectarray Antenna

AbstractThe NASA/Goddard Space Flight Center’s (GSFC’s) W-band (94 GHz) Cloud Radar System (CRS) has been comprehensively updated to modern solid-state and digital technology. This W-band (94 GHz) radar flies in nadir-pointing mode on the NASA ER-2 high-altitude aircraft, providing polarimetric reflectivity and Doppler measurements of clouds and precipitation. This paper describes the design and signal processing of the upgraded CRS. It includes details on the hardware upgrades (SSPA transmitter, antenna, and digital receiver) including a new reflectarray antenna and solid-state transmitter. It also includes algorithms, including internal loop-back calibration, external calibration using a direct relationship between volume reflectivity and the range-integrated backscatter of the ocean, and a modified staggered-PRF Doppler algorithm that is highly resistant to unfolding errors. Data samples obtained by upgraded CRS through recent NASA airborne science missions are provided.

scholarly journals An efficient wide-band signal detection and extraction method

2021 ◽  
Vol 336 ◽  
pp. 04011
Author(s):  
Qian Cheng ◽  
Kexian Gong ◽  
Min Zhang ◽  
Xiaoyan Liu
Keyword(s):  
Computational Complexity ◽  
Signal Detection ◽  
Filter Bank ◽  
Wide Band ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Channelized Receiver ◽  
Multi Phase ◽  
Receiver Model ◽  
Band Signal

Aiming at the influence of time-varying and frequency-varying of noise on the signal detection performance in the short wave wide-band channel and the large amount of computation in the channelized receiver model of the traditional low pass filter bank, a cross-channel reconfigurable multi-phase high-efficiency channelization method based on morphological processing is proposed in this paper .Firstly, The wide-band signal is coarsely filtered by the multi-phase structure of the uniform filter bank which is determined by the protection interval between signals, and then the bandwidth and position of the signal are determined by improved morphological operation and threshold decision of the power spectrum. Finally, the sub-band signals across the channel are combined to complete the approximate reconstruction of the sub-signals. Compared with the computational complexity of traditional channelized receiver model, the results show that this method has lower computational complexity. The simulation results show that the method can achieve the approximate constant false alarm rate(CFAR) under the colored noise environment, and has higher detection capability under different signal-to-noise ratios(SNR).

Digital Design and Numerical Control Processing of Deflection Yoke Based on Top-Down

2012 ◽  
Vol 220-223 ◽  
pp. 373-376
Author(s):  
Huan Lin ◽  
Dong Qiang Gao ◽  
Zhi Fang Shi ◽  
Jiang Miao Yi
Keyword(s):  
Machine Tool ◽  
Product Design ◽  
Digital Technology ◽  
Digital Design ◽  
Numerical Control ◽  
Top Down ◽  
Control Machine Tool ◽  
Implementation Method ◽  
Control Machine

In this paper, it introduces the design processing and implementation method of digital technology based on Top-down, analysis the advantages of the method using Top-down in the product design. To deflection yoke for example, completed digital design and assembly of the deflection yoke based on Top-down, and completed the NC processing by using numerical control machine tool

scholarly journals Radar Imager for Mars’ Subsurface Experiment—RIMFAX

2020 ◽  
Vol 216 (8) ◽  
Author(s):  
Svein-Erik Hamran ◽  
David A. Paige ◽  
Hans E. F. Amundsen ◽  
Tor Berger ◽  
Sverre Brovoll ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Sand Dunes ◽  
Landing Site ◽  
Wide Band ◽  
Center Frequency ◽  
Depth Range ◽  
Fmcw Radar ◽  
Shallow Subsurface ◽  
Eventual Return ◽  
Ground Penetrating

AbstractThe Radar Imager for Mars’ Subsurface Experiment (RIMFAX) is a Ground Penetrating Radar on the Mars 2020 mission’s Perseverance rover, which is planned to land near a deltaic landform in Jezero crater. RIMFAX will add a new dimension to rover investigations of Mars by providing the capability to image the shallow subsurface beneath the rover. The principal goals of the RIMFAX investigation are to image subsurface structure, and to provide information regarding subsurface composition. Data provided by RIMFAX will aid Perseverance’s mission to explore the ancient habitability of its field area and to select a set of promising geologic samples for analysis, caching, and eventual return to Earth. RIMFAX is a Frequency Modulated Continuous Wave (FMCW) radar, which transmits a signal swept through a range of frequencies, rather than a single wide-band pulse. The operating frequency range of 150–1200 MHz covers the typical frequencies of GPR used in geology. In general, the full bandwidth (with effective center frequency of 675 MHz) will be used for shallow imaging down to several meters, and a reduced bandwidth of the lower frequencies (center frequency 375 MHz) will be used for imaging deeper structures. The majority of data will be collected at regular distance intervals whenever the rover is driving, in each of the deep, shallow, and surface modes. Stationary measurements with extended integration times will improve depth range and SNR at select locations. The RIMFAX instrument consists of an electronic unit housed inside the rover body and an antenna mounted externally at the rear of the rover. Several instrument prototypes have been field tested in different geological settings, including glaciers, permafrost sediments, bioherme mound structures in limestone, and sedimentary features in sand dunes. Numerical modelling has provided a first assessment of RIMFAX’s imaging potential using parameters simulated for the Jezero crater landing site.

scholarly journals A Design of Wide Band and Wide Beam Cavity-Backed Slot Antenna Array with Slant Polarization

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Huiying Qi ◽  
Ke Xiao ◽  
Fei Zhao ◽  
Shunlian Chai ◽  
Wenlu Yin
Keyword(s):  
Antenna Array ◽  
Wide Band ◽  
Experimental Results ◽  
Slot Antenna ◽  
Center Frequency ◽  
Challenging Problem ◽  
Wide Beam ◽  
Limited Size

Design of antenna array under the limitation of restricted size is a challenging problem. Cavity-backed slot antenna is widely used because of its advantages of small size, wide band, and wide beam. In this paper, a design of wide band and wide beam cavity-backed slot antenna array with the slant polarization is proposed. To obtain wide band and wide beam with limited size, the inverted microstrip-fed cavity-backed slot antenna (IMF-CBSA) is adopted as the element of 1 × 4 antenna array. The slant polarized antennas and their feeding networks are adopted because of their simple structures. The performance of the proposed antenna array is verified by the simulations and experiments. The measured VSWR < 2 bandwidth is 55% at the center frequency 21.8 GHz, and the gain is larger than 12.2 dB. Experimental results demonstrate that the proposed design achieves wide band and beam with the size of 68 mm × 56 mm × 14.5 mm.

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