| 1. |
- Alfonso Alos, Esperanza, 1979, et al.
(author)
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Parabolic cylindrical reflector antenna at 60 GHz with line feed in gap waveguide technology
- 2013
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In: 7th European Conference on Antennas and Propagation, EuCAP 2013, Gothenburg, Sweden, 8-12 April 2013. - 2164-3342. - 9781467321877 ; , s. 319-323
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Conference paper (peer-reviewed)abstract
- A parabolic cylindrical reflector antenna is proposed in this paper for wireless multi-gigabit communications at 60 GHz. The line feed is realized by a power distribution in parallel plate waveguide (PPW). Inside the PPW waveguide there are metal pin rows forming the contours of an H-plane horn structure in front of a parabolic reflector, where we see possible mechanical advantages in not requiring metal contact of the pins to more than one metal plate. They will still work as a total reflecting wall by making use of the same stopband features as in gap waveguide technology. The result is a low loss, low cost and very versatile 60 GHz antenna with high gain. The electrical design for maximum aperture efficiency and minimum loss is explained.
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| 2. |
- Cerullo, Livia, 1982, et al.
(author)
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Microwave Measurements for Metal Vessels
- 2013
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In: 7th European Conference on Antennas and Propagation, EuCAP 2013, Gothenburg, Sweden, 8-12 April 2013. - 2164-3342. - 9781467321877 ; , s. 3869 - 3873
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Conference paper (peer-reviewed)abstract
- We present two different measurement techniques intended for closed metal vessels, where the objective is to measure the permittivity inside the metal vessel. This problem is relevant for many applications found in e.g. process industry. The first approach exploits the measurement of resonance frequencies, where the metal vessel is used as a microwave resonator. In the second approach, we let the boundary of the metal vessel be equipped with aperture antennas, where the aperture antennas are implemented in terms of rectangular waveguides. The waveguide apertures loads the cavity significantly and we exploit the scattering matrix parameters for the solution of the inverse problem.
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| 3. |
- Cismasu, Marius, et al.
(author)
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Antenna Bandwidth Optimization by Genetic Algorithms with Single Frequency Simulation
- 2013
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In: 2013 7th European Conference on Antennas and Propagation (EuCAP). - 2164-3342. - 9781467321877 ; , s. 2781-2782
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Conference paper (peer-reviewed)abstract
- Antenna Q optimization by a genetic algorithm with method of moments simulation at a single frequency is described. The optimized antennas may have arbitrary shapes within a rectangular region. Simulations using a commercial tool show good agreement between the predicted and realized Q factor. Furthermore, comparison with the physical bound shows that the optimized antennas perform close to the optimum for many electrically small dimensions.
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| 4. |
- Fayazi, Seyedeh Shaghayegh, et al.
(author)
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UWB SAR Imaging of Near-Field Object for Industrial Process Applications
- 2013
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In: 7th European Conference on Antennas and Propagation, EuCAP 2013, Gothenburg, Sweden, 8-12 April 2013. - 2164-3342. - 9781467321877 ; , s. 2245-2248
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Conference paper (peer-reviewed)abstract
- Ultra wideband technology becomes more widely used for near-field object detection. We present an aperture synthetic radar (SAR) system using ultra-wideband (UWB) signals for such applications. One of the problems with UWB time-domain SAR imaging algorithm is the artefact originated from scattered field of adjacent objects. In this paper an algorithm based on the Range Point Migration (RPM) method is used to alleviate this problem. This method estimates a possibility distribution of the optimal Direction of Arrival (DOA) of the scattered field from objects. A weighting factor based on this possibility is used to suppress the effect of artifact scattered fields. The results in the paper show that the UWB SAR accompanied with RPM can produce an image of an object with a significant suppression of undesired artifact from scattered field of adjacent objects.
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| 5. |
- Iupikov, Oleg, 1983, et al.
(author)
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A Plane Wave Approximation in the Computation of Multiscattering Effects in Reflector Systems
- 2013
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In: 7th European Conference on Antennas and Propagation, EuCAP 2013, Gothenburg, Sweden, 8-12 April 2013. - 2164-3342. - 9781467321877 ; , s. 3828-3832
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Conference paper (peer-reviewed)abstract
- A hybrid MoM/PO method for the analysis of multiple scattering effects between reflector and large feeds, such as dense multibeam phased array feeds or multifrequency front-ends (MFFEs) in which higher frequency feeds operate in the vicinity of an extended metal structure, has been presented and studied. This paper evaluates the accuracy and computational efficiency for the MoM/PO method with and without using a uniform plane wave approximation of the reflector scattered field.
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| 6. |
- Li, Hui, et al.
(author)
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Calculating signal correlation in lossy dipole arrays using scattering parameters and efficiencies
- 2013
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In: 2013 7th European Conference on Antennas and Propagation, EuCAP 2013. - : EurAAP. - 2164-3342. - 9788890701832 - 9781467321877 ; , s. 519-523
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Conference paper (peer-reviewed)abstract
- Correlation coefficient, as a critical performance metric of multiple antenna systems, can be calculated from the 3D radiation patterns of the antennas for multipath environments with uniform 3D angular power spectrum. A simpler, faster and lower cost approach uses the antennas' scattering parameters to determine correlation coefficient. However, the method assumes lossless antennas, and hence only achieves good accuracy for antennas with high radiation efficiencies. In this work, a method for calculating correlation coefficients in lossy dipole arrays is proposed, using only the scattering parameters and radiation efficiencies. The method is based on the equivalent circuit of antennas, and it gives a significantly better estimate of the correlation coefficient than the existing methods. The proposed method is also applied to two folded monopole antennas in a compact terminal to demonstrate its effectiveness.
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| 7. |
- Vakili, Iman, et al.
(author)
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Pulse transmission using leaky lens antenna and RTD-MOSFET wavelet generator
- 2013
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In: [Host publication title missing]. - 2164-3342. - 9781467321877 ; , s. 324-325
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Conference paper (peer-reviewed)abstract
- A leaky lens antenna system for short pulse applications is designed, fabricated and characterized. The antenna has very good phase center stability over large bandwidths. The leaky lens antenna is connected to an in-house wavelet generator to transmit 100 ps pulses centered at 57.5 GHz. It is shown that the antenna preserves the reference pulse shape and has very low dispersion.
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| 8. |
- Vasilev, Ivaylo, et al.
(author)
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Adaptive impedance matching performance of MIMO terminals with different bandwidth and isolation properties in realistic user scenarios
- 2013
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In: European Conference on Antennas and Propagation (EuCAP), 2013. - 2164-3342. - 9788890701832 - 9781467321877 ; , s. 2590-2594
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Conference paper (peer-reviewed)abstract
- Using the metric of channel capacity, three dual-antenna multiple-input multiple-output (MIMO) terminals with adaptive impedance matching were evaluated at LTE Band 13 in four different user scenarios using simulation. Each of the three terminals is equipped with a slot-monopole antenna and a planar inverted-F antenna (PIFA). The slot monopole is fixed at one edge of the chassis, whereas the location of the PIFA differs among the terminals to provide different bandwidth and isolation characteristics in free space (FS). The results show that adaptive matching leads to an average capacity gain of up to 24% at the center frequency, favoring the terminal with the smallest antenna bandwidth and the largest isolation. However, the maximum capacity gain from adaptive matching decreases to 15.7% when averaged over the entire system bandwidth. Moreover, the terminal with moderate antenna bandwidth and isolation offers the best overall absolute capacity performance under different user scenarios, indicating a design tradeoff. These results highlight important design considerations for MIMO terminals with adaptive impedance matching.
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| 9. |
- Xiaoming, Chen, 1983, et al.
(author)
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Investigation of the Distribution of the Random LOS Component in a Reverberation Chamber
- 2013
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In: 7th European Conference on Antennas and Propagation, EuCAP 2013, Gothenburg, Sweden, 8-12 April 2013. - 2164-3342. - 9781467321877 ; , s. 2551-2554, s. 2551-2554
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Conference paper (peer-reviewed)abstract
- In the previous measurement uncertainty work by Kildal, et al. (2012), the random line-of-sight (LOS) component in a reverberation chamber (RC) was assumed to be Gaussian distributed without quantitative justification. In the present paper, we apply goodness-of-fit (GOF) test to the measured LOS component samples to check its Gaussianity. It is shown that the Gaussianity hypothesis of the distribution of the random LOS component is accepted at most of the frequencies, which justifies the Gaussian LOS component assumption.
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| 10. |
- Al-Rawi, Ali, 1985, et al.
(author)
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The Double-sided 4-port Bow-tie Antenna: A New Compact Wideband MIMO Antenna
- 2013
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In: 7th European Conference on Antennas and Propagation, EuCAP 2013, Gothenburg, Sweden, 8-12 April 2013. - 2164-3342. - 9788890701832 ; , s. 3731-3735
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Conference paper (peer-reviewed)abstract
- We present a new compact ultra-wideband 4-port antenna for use in MIMO systems, such as in reverberation chambers for OTA measurements. The new antenna is based on the self-grounded bow-tie antenna with a very compact size. The design was done through an optimization by employing the genetic algorithm in order to obtain low reflection coefficient and mutual coupling between ports. The designed antenna has an embedded radiation efficiency higher than -0.35 dB, reflection coefficient below -7 dB, mutual coupling between ports below - 12.5 dB (in most frequencies below -20 dB), over a frequency range of 0.4–15 GHz.
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