scholarly journals BPSK Modulation-Based Local Oscillator-Free IQ Demodulation for Millimeter Wave Imaging

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Qibin Zheng ◽  
Yanpeng Jian ◽  
Lei Wang ◽  
Ziyue Ma ◽  
Xinyu Li ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Sampling Rate ◽  
Three Dimensional ◽  
Intermediate Frequency ◽  
Local Oscillator ◽  
Radar Imaging ◽  
Sampling Theorem ◽  
Shift Keying ◽  
The Hilbert Transform ◽  
Bpsk Modulation

The precision of local oscillator (LO) signal in in-phase and quadrature (IQ) demodulation strongly affects the imaging performance of millimeter wave (mmWave) radars. Therefore, to eliminate the requirement for high-precision LO, a simple yet effective digital IQ demodulation method has been proposed with the aid of a specified sampling scheme in order to eliminate the demand for LO. Based on the bandpass sampling theorem, the characteristic of the intermediate frequency signal of mmWave imaging indicates that the LO is unrequired if the sampling rate is twice of the frequency of the carrier of the intermediate signal. In this way, the in-phase signal would be directly and accurately obtained by performing the Binary-Phase-Shift-Keying (BPSK) modulation on the samples, based on which the IQ demodulation would be completed by using the Hilbert transform. The proposed method does not employ LO and thus simplifies the demodulation process and is suitable for implementation in a Field-Programmable Gate Array (FPGA) with fewer hardware resources. To verify the method, a three-dimensional mmWave radar imaging is carried out at the 30-34 GHz bandwidth, where the sampling and digital IQ demodulation are realized by an ADC (AD9250) and FPGA (XC7K325T), respectively. The results show a simplified transceiver with lower requirements and the prospect of the proposed method being applied in radar imaging and other related fields.

scholarly journals Cylindrical Three-Dimensional Millimeter-Wave Imaging via Compressive Sensing

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Guoqiang Zhao ◽  
Shiyong Li ◽  
Bailing Ren ◽  
Qingwei Qiu ◽  
Houjun Sun
Keyword(s):  
Compressive Sensing ◽  
Millimeter Wave ◽  
Imaging Techniques ◽  
New Technology ◽  
Three Dimensional ◽  
Sampling Theorem ◽  
Future Application ◽  
Imaging Method ◽  
Wave Imaging ◽  
The Cost

Millimeter-wave (MMW) imaging techniques have been used for the detection of concealed weapons and contraband carried by personnel. However, the future application of the new technology may be limited by its large number of antennas. In order to reduce the complexity of the hardware, a novel MMW imaging method based on compressive sensing (CS) is proposed in this paper. The MMW images can be reconstructed from the significantly undersampled backscattered data via the CS approach. Thus the number of antennas and the cost of system can be further reduced than those based on the traditional imaging methods that obey the Nyquist sampling theorem. The effectiveness of the proposed method is validated by numerical simulations as well as by real measured data of objects.

scholarly journals An Ultra-Wideband Microwave Photonic Channelized Receiver with Zero-IF Architecture

2019 ◽  
Vol 10 (1) ◽  
pp. 30 ◽  
Author(s):  
Bo Chen ◽  
Yangyu Fan ◽  
Zhou Tian ◽  
Wuying Wang ◽  
Bochao Kang ◽  
...  
Keyword(s):  
Frequency Comb ◽  
Optical Filter ◽  
Intermediate Frequency ◽  
Local Oscillator ◽  
Optical Frequency Comb ◽  
Ultra Wideband ◽  
Optical Frequency ◽  
Analog To Digital ◽  
Shift Keying ◽  
Channelized Receiver

A scheme for realizing a zero-intermediate frequency (IF) channelized receiver using a dual-polarization quadrature phase-shift keying (DP-QPSK) modulator and a narrow-band optical filter is proposed. The channelized system only requires one optical frequency comb to achieve zero-IF multi-channel reception of wideband signals, and the spacing of the optical frequency comb only needs to be equal to the sub-channel width, which is very easy to implement. It is found that using photonic IQ demodulation and balanced detection and reception technology can not only eliminate many disadvantages of the traditional zero-IF receiver, including local oscillator (LO) leakage, direct current (DC) offset, even-order distortion, and in-phase/quadrature (I/Q) imbalance, but also reduce the bandwidth and sample rate of the analog-to-digital converter (ADC). It is theoretically proven that the radio frequency (RF) signal with a bandwidth of 3 GHz can be divided into five sub-channels with a bandwidth of 600 MHz and finally demodulated to I/Q basebands, which are also verified with simulation.

Millimeter-wave dual-mode and dual-band switchable Gilbert up-conversion mixer in 65-nm CMOS process

2021 ◽  
pp. 1-5
Author(s):  
Fang Zhu ◽  
Guo Qing Luo
Keyword(s):  
Millimeter Wave ◽  
Complementary Metal Oxide Semiconductor ◽  
Local Oscillator ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Dual Band ◽  
Cmos Process ◽  
Pumping Power ◽  
Dual Mode ◽  
Dc Power

Abstract In this paper, a millimeter-wave (MMW) dual-mode and dual-band switchable Gilbert up-conversion mixer in a commercial 65-nm complementary metal oxide semiconductor (CMOS) process is presented. By simply changing the bias, the proposed CMOS Gilbert up-conversion mixer can be switched between subharmonic and fundamental operation modes for MMW dual-band applications. With a low local oscillator pumping power of 3 dBm and low dc power consumption of 6 mW, the proposed CMOS Gilbert up-conversion mixer exhibits a measured conversion gain of −0.5 ± 1.5 dB from 37 to 50 GHz and 2.5 ± 1.5 dB from 17.5 to 32 GHz for the subharmonic and fundamental modes, respectively.

Note: Three-dimensional stereolithography for millimeter wave and terahertz applications

2012 ◽  
Vol 83 (4) ◽  
pp. 046103 ◽  
Author(s):  
A. Macor ◽  
E. de Rijk ◽  
S. Alberti ◽  
T. Goodman ◽  
J-Ph. Ansermet
Keyword(s):  
Millimeter Wave ◽  
Three Dimensional ◽  
Terahertz Applications

A Hybrid Synthetic Aperture and Time-Reversal MUSIC Algorithm for Subwavelength Radar Imaging

2021 ◽  
Author(s):  
Nathaniel Tamminga ◽  
Brianna Christensen ◽  
Sarah Petry ◽  
Enson Chang
Keyword(s):  
Synthetic Aperture Radar ◽  
Millimeter Wave ◽  
Time Reversal ◽  
Radar Imaging ◽  
Synthetic Aperture ◽  
Music Algorithm ◽  
Subwavelength Imaging ◽  
Chipless Rfid ◽  
Imaging Approach ◽  
Printing Cost

A promising chipless RFID approach uses millimeter-wave synthetic aperture radar (SAR) to image metal ink-printed ID tags from a meter or more away. Due to printing cost, it is desirable to minimize the size and spacing of metal patches within a tag, preferably into the subwavelength regime. Although circular SAR (CSAR) has a sharply peaked point response in 2D, its side lobes of closely-spaced targets interfere strongly with each other to distort the image. An alternative 2D subwavelength imaging approach with minimal side lobes is Time-Reversal MUSIC (TR-MUSIC). Traditional TR-MUSIC, however, requires a large number of transmitters and receivers. We propose a hybrid synthetic aperture TR-MUSIC algorithm (SATR-MUSIC) that combines the benefits of both approaches. Using relatively few transceivers, SATR-MUSIC is able to resolve objects separated by approximately  in 2D with minimal background artifacts. It does so by averaging TR-MUSIC’s imaging kernel incoherently over the synthetic aperture.

Contributed Review: Advanced three-dimensional laser radar imaging with the airborne optical systems testbed

2018 ◽  
Vol 89 (10) ◽  
pp. 101502 ◽  
Author(s):  
Marius A. Albota ◽  
Rajan Gurjar ◽  
Anthony Mangognia ◽  
Daniel Dumanis ◽  
Brendan Edwards
Keyword(s):  
Three Dimensional ◽  
Radar Imaging ◽  
Optical Systems ◽  
Laser Radar
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