- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Two-Stage Beamforming for Phased Array Imaging using the Fast Hankel Transform
摘要： An ultrasound scan generates a huge amount of data. To form an image this data has to be transferred to the imaging system. This is an issue for applications where the data transfer capacity is limited such as hand-held systems, wireless probes and miniaturized array probes. Two-stage beamforming methods can be used to significantly reduce the data transfer requirements. In the first stage, which is applied in-probe, the amount of data is reduced from channel to scanline data. In the imaging system the data is then beamformed to obtain images that are synthetically focused over the entire image. Currently two approaches exist for the second stage. The first approach is a time-of-flight approach called synthetic aperture sequential beamforming (SASB) that has been developed for both linear and phased arrays. SASB does however introduce artefacts in the image that can be reduced by tapering the first stage scan lines at the cost of lateral resolution. The second approach is based on the wave equation, but a computationally efficient method for phased arrays that is producing sector scan data is lacking. Here we propose an algorithm that uses the fast Hankel transform to obtain a fast algorithm. The imaging performance of this method is evaluated with simulations and experiments. Compared with PSASB, which is an adaption of SASB for phased arrays, our method requires a similar amount of operations to construct the entire image and there is no trade-off between resolution and artefacts. These results show the advantage of using the wave equation instead of a time-of-flight approach.
关键词： Ultrasound imaging,two-stage beamforming,synthetic aperture,phased array,migration
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE Research and Applications of Photonics In Defense Conference (RAPID) - Miramar Beach, FL (2018.8.22-2018.8.24)] 2018 IEEE Research and Applications of Photonics In Defense Conference (RAPID) - Integrated Photonics for RF-Photonic Phased-Array Radar System
摘要： We discuss some potential benefits of using integrated RF-photonic devices/circuits in a phased-array-Radar system. A viable and simple solution is proposed for a low-cost, RF-photonic multi-beams beamformer that meets both transmitting and receiving RF-system specifications/requirements. Proof-of-concept experiments and chip-scale integrated-photonics subsystem development will also be discussed.
关键词： Phased array Radar,Fiber optics links and subsystems,Optical control of phased array antenna,Radio frequency photonics,Integrated Photonics
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - A planar dual-polarized ultra-wideband millimeter-wave array antenna
摘要： We present a dual-polarized ultra-wideband element in an in?nite large array condition for planar phased array antennas in mm-wave applications. The array antenna consists of tightly-coupled bowties in a dual-offset con?guration. In order to simplify the manufacturing process and eliminate the scalability limitation, a new feeding network is employed. The feeding is inspired by magneto-electric dipoles (MEDs) and planar ultra-wideband array antennas (PUMAs). Hence, the feeding is integrated with the horizontally oriented radiating bowties and removes the need for the external baluns. The simulated antenna shows relative bandwidths of 2.3 : 1 and 3 : 1 at VSWR<3, for maximum scanning angles of 60? and 45?, respectively, at both E- and H-planes.
关键词： mm-Wave,Phased array antenna,UWB,Array antenna
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Uniform Arrays with Low Sidelobe Two-Way Antenna Patterns
摘要： The peak sidelobe level of a two-way array factor resulting from a uniform transmit and uniform receive apertures can be lowered by making the two apertures different sizes. The concept is demonstrated using uniform linear and uniform receive arrays with different number of elements and one array has a null in the direction of the first sidelobe of the other.
关键词： antenna array,low sidelobes,two-way antenna pattern,phased array
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - SIW Based Antenna Array with Power Equalization in Elevation Plane for 5G Base Stations
摘要： In this paper, we present a 5G base station phased array antenna concept based on the power flux equalization in the elevation plane. We designed an aperture- coupled microstrip patch sub-array fed by a substrate integrated waveguide to produce a cosecant radiation pattern in the elevation plane. The antenna is designed to be operational at frequencies around 28.5GHz, targeting a candidate 5G mm-wave frequency band. The dimensions of the cosecant antenna sub-array support wide-angle scanning of the final phased array antenna in the horizontal plane. The antenna exhibits good impedance and radiation properties in the scanning range +/- 45deg.
关键词： cosecant radiation pattern,microstrip patch antenna,substrate integrated waveguide,phased array antenna,5G base station
更新于2025-09-04 15:30:14
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Analysis and Design of High Frequency 1-D CMUT Imaging Arrays in Non-collapsed Mode
摘要： High frequency ultrasound imaging arrays are important for a broad range of applications, from small animal imaging to photoacoustics. CMUT arrays are particularly attractive for these applications as low noise receiver electronics can be integrated for an overall improved performance. In this paper we present a comprehensive analysis of high frequency CMUT arrays based on an experimentally verified CMUT array simulation tool. The results obtained on an example, a 40 MHz 1-D CMUT array for intravascular imaging, are used to obtain key design insights and tradeoffs for receive only and pulse-echo imaging. For the receiver side, thermal mechanical current noise, plane wave pressure sensitivity, and pressure noise spectrum are extracted from simulations. Using these parameters, we find that the receiver performance of CMUT arrays can be close to an ideal piston, independent of gap thickness and applied DC bias, when coupled to low noise electronics with arrays utilizing smaller membranes performing better. For pulse-echo imaging, thermal mechanical current noise limited SNR is observed to be dependent on the maximum available voltage and gap thickness. In terms of bandwidth, we find that Bragg resonance of the array, related to the fill factor, is a significant determinant of the high frequency limit and the fluid loaded single membrane resonance determines the lower limit. Based on these results, we present design guidelines requiring only fluid loaded single membrane simulations and membrane pitch to achieve a desired pulse-echo response. We also provide a design example and discuss limitations of the approach.
关键词： CMUT,Bragg’s resonance,CMUT design,High frequency arrays,Phased array,Photoacoustic receiver
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - High-gain Series-fed Phased Array Antenna for Wearable Wireless Applications
摘要： A new varactor controlled series-fed scanning array antenna is introduced. At the center of the design is a varactor controlled phase shifter, where varactor capacitance is changed by applying different bias voltages which alters the progressive phase between series-fed dipole input currents and allows array pattern to be scanned (-25, 0, 25 degrees). Good return loss (greater than 10 dB), high gain (10 dB), and beam scanning (within plus minus 25 degrees) with nulls between two consecutive beams are achieved.
关键词： Phased Array,Varactor controlled,Electronic beam steering
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Dual-Band 5G Millimeter-Wave MIMO Antenna Array for Mobile Phone Application
摘要： In this paper, a dual-band 5G millimeter-wave antenna array for 37-40 GHz mobile application is proposed. The proposed antenna has two resonances generated by a monopole branch and a loop branch. The two branches are located on the surface of a ceramic block, and the antenna is mounted on PCB. Possible locations of the MIMO antenna array in a mobile phone are studied and an optimized location for the MIMO antenna system is proposed.
关键词： beam forming,5G mm-wave,phased-array antenna
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Finger Ring Phased Antenna Array for 5G IoT and Sensor Networks at 28 GHz
摘要： In this paper, a circular phased antenna array has been constructed on the finger ring for the 28 GHz 5G communication systems. The antenna array has been verified in free space and with user’s hand phantom on three fingers by the simulations. It has been found that such antenna structure is resilient towards the user effects and has a stable coverage efficiency characteristics. The coverage efficiency of 80 % with the realized gain of 5 dBi has been observed when the ring simulated with the user’s hand. The correlation between high power loss density with antenna de-tuning has also been observed.
关键词： 5G,Wearable Antennas,Sensor Networks,28 GHz,Phased Array,IoT,Finger Ring Antenna,User effects,Antennas
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Compensation Method for Distorted Active Phased Array Antennas in Condition of Quantization Errors Based on Structural-Electromagnetic Coupling
摘要： Widely used digital attenuator and phase shifter could inevitably introduce quantization errors for distorted active phased array antenna, at the time of controlling the amplitude and phase for improving the electromagnetic performance. The reduction of quantization errors decides the compensation effect service for antenna environment. Therefore, a compensation method for distorted antenna in condition of quantization errors is presented based on the coupled structural-electromagnetic model with least squares method. The quantized amplitude and phase adjustments are deduced from the perspective of multiple dividing of minimum quantization value and the optimal amplitude and phase differences, which could be implemented to recover a high quality pattern from a distorted antenna. Lastly, an X-band active phased array antenna with representative saddle shape deformation is illustrated to verify the compensation effect for quantization errors including both the amplitude and phase.
关键词： structural-electromagnetic coupling,quantization errors,active phased array antenna,deformation,amplitude and phase compensation
更新于2025-09-04 15:30:14