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- 摘要
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[IEEE 2018 IEEE International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM) - Nagoya (2018.8.29-2018.8.31)] 2018 IEEE International Workshop on Electromagnetics:Applications and Student Innovation Competition (iWEM) - E-Plane Beam-Forming Performance of Rotman-Lens in Multi-Layer Substrate
摘要： A two-dimensional Rotman-lens feeding circuit was proposed for planar two-dimensional multi-beam antenna using multi-layer substrate integrated waveguide in the millimeter-wave band. In this work, an E-plane Rotman-lens for two-dimensional Rotman-lens was designed and the E-plane beam-forming performance was evaluated by array factors from the simulated S-parameters.
关键词： multi-beam antenna,feeding circuit,multi-layer substrate,millimeter-wave,Rotman-lens
更新于2025-09-23 15:22:29
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COMPACT ROTMAN LENS STRUCTURE CONFIGURATIONS TO SUPPORT MILLIMETER WAVE DEVICES
摘要： The development of modern communication devices for the latest technologies such as 5G has brought the millimeter wave technology into the spotlight because it offers higher data rates and bandwidth. Since highly directional transmissions are necessary for communication in these frequencies due to high path loss and atmospheric absorption, the use of adaptive antennas is inevitable. Rotman lenses have long been used as analog beam forming networks to support linear array antennas for electronic scanning. Their broad bandwidth and planar structure make them ideal for a variety of applications. However, their overall dimensions can be prohibitive especially for large scan angles. In this paper, we propose a few compact configurations that reduce the overall dimensions of Rotman lens as much as 50% without degrading its performance.
关键词： compact configurations,Rotman lens,millimeter wave,beam forming networks,electronic scanning
更新于2025-09-23 15:21:21
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Multibeam Monopulse SIW Slot Array Antenna
摘要： A multibeam slot array antenna is proposed in the 10-GHz band for a monopulse tracking system with resolution enhancement techniques. The antenna architecture combines a four-subarray SIW slot antenna, a multibeam-forming network of microstrip Rotman lens array, and a SIW comparator of four-quadrant monopulse technique. A method to form difference patterns in both E-plane and H-plane for mutibeams is presented, and the method can improve the accuracy of angle detection for all beams. The key point of the method is to compensate the phase difference caused by the beam deflection between two subarrays (quadrants) by constraining input delay lines of the Rotman lens array. To validate the proposed concepts, an antenna prototype is realized and measured. The experimental results demonstrate a scanning range of ±36° with -5 dB crossover level between two adjacent sum beams in the E-plane. The corresponding beams of difference pattern are generated in E-plane and H-plane via the monopulse comparator to enhance angle resolution. The multibeam monopulse system can achieve gains between 21.7 dBi and 23.5 dBi for all sum beams at the center frequency of 10 GHz. The lobe imbalances are less than 1.1 dB and null depths are lower than -16 dB for all difference patterns. This multibeam monopulse slot antenna can be applied in radar and communication systems requiring beam-scanning capabilities and target tracking.
关键词： slot array,Rotman lens,monopulse antenna,substrate integrated waveguide (SIW),Multibeam antenna
更新于2025-09-23 15:21:01
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[IEEE 2018 IEEE MTT-S International Microwave Workshop Series on 5G Hardware and System Technologies (IMWS-5G) - Dublin (2018.8.30-2018.8.31)] 2018 IEEE MTT-S International Microwave Workshop Series on 5G Hardware and System Technologies (IMWS-5G) - On the Impact of Spillover Losses in 28 GHz Rotman Lens Arrays for 5G Applications
摘要： This work demonstrates the sensitivity of lens antenna arrays operating at millimeter-wave (mmWave) frequencies. Considering a Rotman lens array in receive mode, our investigation focuses on its most imperative defect: aberration of electromagnetic (EM) energy. Aberration leads to spillover of electric fields to neighboring ports, reducing the lens’ ability to focus the EM energy to a desired port. With full EM simulations, we design a 28 GHz, 13 beam and 13 array port Rotman lens array to characterize its performance with the aforementioned impairment. Our findings show that the impact of aberration is more pronounced when the beam angles are close to the array end-fire. More critically, the corresponding impact of aberration on the desired signal and interference powers is also investigated for an uplink multiuser cellular system operating at 28 GHz. The presented results can be used as a reference to re-calibrate our expectations for Rotman lens arrays at mmWave frequencies.
关键词： Rotman lens,5G,spillover losses,millimeter-wave,aberration
更新于2025-09-23 15:21:01
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Tri-Focal Configuration of Three-Dimensional Metallic Waveguide-Array Lens Antennas of Rotman Lens Concept for Multi-Beam Applications
摘要： This paper presents a design methodology of three-dimensional (3-D) passive metallic waveguide-array lens antenna (MWALA) by implementing the Rotman lens concept (RLC) for collinear multi-beam radiations on the same angular plane. The RLC methodology extends the original concept of two-dimensional (2-D) tri-focal Rotman lens into a 3-D one in free space. Thus, the MWALA has a planar aperture facing to the radiation boresight to resemble a planar phased array of waveguide antennas and also has a curved focal surface pro?le (CFSP) on the opposite side to receive the illumination by the radiations of feed antennas. The three co-planar focal points are speci?ed to de?ne a circular focal arc (CFA) for multiple feed placement to radiate multi-beams through this MWALA. The boundary formed by the CFSP and CFA resembles the shape of Rotman lens equivalently realized in free space. In addition, the shortage of freedoms in conventional MWALA design limited to dual-focus con?gurations and resulting in narrow scan angles, is relaxed by adopting the phase velocities inside the waveguides as an additional freedom to realize a tri-focal con?guration and broaden the scan angles of multi-beam radiation. Theoretical foundation and design guidelines are summarized with numerical and experimental examples presented to validate the feasibility.
关键词： Antenna radiation,Rotman lens,multi-beam radiation,waveguide array lens antenna
更新于2025-09-19 17:13:59
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A low-profile 28-GHz Rotman lens-fed array beamformer for 5G conformal subsystems
摘要： This paper reports on the first demonstration of an experimental millimeter-wave (mm-wave) beamforming based on the conformal Rotman lens. The passive switched-beam network is intended for operation in the 28-GHz band, covering the 18-38 GHz range, for the deployment in the fifth generation (5G) subsystems. The primary objective of this work is to conduct the feasibility of designing a beamforming network (BFN) based on the liquid-crystal polymer substrate, and to evaluate the performances in terms of the scattering (S)-parameters and surface currents for the proposed flexural case of the convex-circumferential bending. A prototype has been accurately fabricated, and a setup has also been deployed to conduct the measurements. The performance in terms of the linear progressive phase behavior, as the main figure of merit, has been shown. The BFN exhibits significant characteristics to be used as a low-profile unit of the transceivers with the in-built beam steering for the conformal 5G subsystems.
关键词： beamforming network,Rotman lens,5G,mm-wave,wireless subsystem,conformal antenna array
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE International Conference on Communications (ICC 2018) - Kansas City, MO (2018.5.20-2018.5.24)] 2018 IEEE International Conference on Communications (ICC) - Uplink Interference Analysis with RF Switching for Lens-Based Millimeter-Wave Systems
摘要： In this paper, we take a fundamental look at the interference characteristics of a lens–based millimeter–wave multiuser multiple–input multiple–output system. We consider a hybrid architecture, implemented via a bank of radio–frequency (RF) switches which perform beam selection followed by low–complexity uplink maximum–ratio combining at baseband. Considering a Rotman lens antenna array in line–of–sight propagation, we derive tight analytical expressions for the average (expected) interference power of an arbitrary user terminal, with and without the presence of RF switching. Our mathematical expressions show that without RF switching, the Rotman lens losses its bene?ts and collapses to a conventional uniform linear array. Numerical results demonstrate that the expected interference power of a given terminal decreases signi?cantly with RF switching, due to the beam selection process separating multiple uplink direction–of–arrivals (DoAs). This is in contrast to the case when there is no RF switching, which relaxes the beam selection constraints and thus allows very similar DoAs. Overall, the results in this paper emphasize the necessity of RF switching in order to obtain superior performance with a Rotman lens array, over conventional phased arrays.
关键词： multiuser multiple–input multiple–output,Rotman lens,RF switching,interference power,millimeter–wave
更新于2025-09-09 09:28:46
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[IEEE 2018 15th European Radar Conference (EuRAD) - Madrid, Spain (2018.9.26-2018.9.28)] 2018 15th European Radar Conference (EuRAD) - Analog Beamforming based on Fourier Rotman Lens for Multibeam Applications
摘要： Spatial division represents a popular approach to increasing capacity in modern wireless networks. This paper presents a study of a simplified beamforming network based on a Fourier transform network with the number of output ports lower than the number of the elements in the antenna array. It is shown that connecting the output ports of Fourier transform network via power dividers to several array elements in phase, thus implementing a nearest-neighbor phase interpolation, preserves the gain and width of the beams in a narrow scanning sector. Therefore, in applications where few orthogonal beams are required to span a narrow spatial sector, the proposed approach can offer reduction of the hardware complexity. The simulated radiation patterns for a phase interpolation Fourier beamforming network are demonstrated. The antenna radiation patterns have been measured, using a Fourier Rotman lens with 2-way Wilkinson power dividers, which confirmed the simulated trends.
关键词： Rotman lens,beamforming,Fourier transform beamforming,Antenna arrays
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 Novel Electronically Wideband Steering System using Rotman Lens for 5G Applications at 28 GHz
摘要： this paper presents the design, simulation and measurement results for a beam steerable system, which covers the frequency range from 22 GHz to 35 GHz for 5G applications. A Rotman Lens with five input ports and six output ports is the beamforming network that is connected to a six circular patch L-shaped reflector antennas. This novel system covers a wide scanning angle from -45 to +45 degree for all frequencies. In addition, the simulated and measured results show that the Rotman Lens fed-antenna array has the S11 response less than 10dB in the frequency range of 22 to 35 GHz.
关键词： Beamforming,steering system,Rotman Lens,5G,array antenna
更新于2025-09-04 15:30:14