Design of a 4×4 butler matrix for beamforming antenna applications
01 Dec 2014-pp 1-4
TL;DR: This paper focuses on the design of a planar 4×4 butler matrix functioning at 2.45 GHz band frequency and implemented a simple microstrip structure with single layer to exploit this matrix as a beam forming network generating orthogonal beams oriented towards various directions.
Abstract: This paper focuses on the design of a planar 4×4 butler matrix functioning at 2.45 GHz band frequency. The purpose is to exploit this matrix as a beam forming network generating orthogonal beams oriented towards various directions. For that, we have implemented a simple microstrip structure with single layer. We have also integrated some microwave devices, namely phase-shifters, 3 dB couplers and cross-couplers.
Citations
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TL;DR: In this article, the authors present an extensive review of the Butler Matrix (BM) based beamforming networks, and discuss which type of BM will be suitable for the phased array antenna (PAA) systems in the upcoming 5G and next-generation of B5G wireless systems.
Abstract: Due to the rapid development of wireless communication technologies, the number of wireless users are radically increasing. Currently, $\sim 23$ billion wireless devices are connected to the internet, and these numbers are expected to increase manifolds in the years to come. The technology growth of the fifth-generation (5G) wireless systems will be needed to meet this high demand of the network. 5G wireless systems offer data-rates of up to 10Gbps, 1-ms latency, and reduced power consumption. It is a known fact that 5G wireless systems will be exploiting beyond the presently used 3 GHz microwave and millimetre-wave (mm-wave) frequency bands. This is the primary driver in the development of the 5G wireless system. Multi-beam Phased array antenna (PAA) systems are typically used in the deployment of 5G systems for high-gain and directionality. In current 5G and future Beyond 5G (B5G) antenna array systems, beamforming networks (BFNs) such as the Butler Matrix (BM) will play a key role in achieving multi-beam characteristics. So, this paper presents an extensive review of the BM based BFNs, and discusses which type of BM will be suitable for the phased array antenna (PAA) systems in the upcoming 5G and next-generation of B5G wireless systems. Moreover, this paper also summarizes the different types of BM designs based on the number of layers. The BMs are classified into the bi-layer, tri-layer, and four-layer structures. It includes different techniques that have been used to solve the problem of crossing, narrow bandwidth, and size reduction of the BM. From the previous studies, it is found that most of the past research work was performed using the bi-layer BM system, whereas the difficult geometries like tri- and four-layer BM are avoided due to their complex fabrication process. It is also found in this paper that the metamaterial (MTM) based bi-layer BM achieves low insertion-loss and phase-error, excellent bandwidth and compact size, and good S-parameter performance, which makes them an ideal BFN candidate for the upcoming 5G and next-generation B5G systems.
43 citations
TL;DR: A low-complexity approximation for the 16-point DFT and its respective multiplierless fast algorithm is proposed and achieves RF beam performance similar to the DFT at the cost of a small error which would be tolerable for the majority of multibeam phased-array receivers.
Abstract: A low-complexity approximation for the 16-point DFT and its respective multiplierless fast algorithm is proposed. A receive mode multibeam phased-array experiment was realized at 2.4 GHz employing a 16-element IQ receiver array that uses the proposed approximate spatial DFT in real-time in order to achieve multibeam digital beamforming. The 16-beam digital receiver experiment uses a ROACH-2 based Xilinx Virtex-6 FPGA platform for both digital beam computation as well as to perform the multireceiver analog-to-digital conversion. Receive mode RF beams were measured and compared to the exact DFT (realized with fixed-point multipliers with 8-bit twiddle factors). The measured approximate DFT closely followed the measured beams resulting from the fixed-point conventional DFT implementation. The approximate DFT achieves RF beam performance (mainlobe gain, sidelobes) similar to the DFT at the cost of a small error which would be tolerable for the majority of multibeam phased-array receivers. The 16-point approximate DFT provides a hardware reduction of $\sim$70% with respect to FFTs, setting up a low size, weight and power (SWaP) system.The maximum magnitude error of the filter bank response is 0.106 ($\approx -20$ dB).
6 citations
01 Sep 2016
TL;DR: This paper describes the development of 4×4 wideband compact Butler matrix operating between 1.6 GHz and 2.4 GHz, which involves two microstrip dielectric layers with a shared ground plane and a coupling slot to attain wideband characteristics.
Abstract: This paper describes the development of 4×4 wideband compact Butler matrix operating between 1.6 GHz and 2.4 GHz. In order to attain wideband characteristics, the matrix uses microstrip-slot technology, which involves two microstrip dielectric layers with a shared ground plane and a coupling slot. The multilayer beamforming network design is compact in size and avoids the use of crossovers, which makes it more advantageous than the conventional Butler matrix. To verify the performances of the beamformer, a four-antenna array is connected to the proposed 4×4 Butler matrix to shape a switched-beam system. Simulation results are presented and discussed.
2 citations
Cites methods from "Design of a 4×4 butler matrix for b..."
...To alleviate this drawback, the use of an elliptical coupler [6] in place of the hybrid enhances the bandwidth....
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TL;DR: In this paper , a complete end-to-end far-field wireless power transfer (WPT) is proposed and studied for the application of the Internet of Things (IoT) at the industrial, scientific, and medical (ISM) band of 2.4 GHz.
Abstract: A complete end-to-end far-field wireless power transfer (WPT) is proposed and studied in this paper for the application of the Internet of Things (IoT) at the industrial, scientific, and medical (ISM) band of 2.4 GHz. The radiative WPT has achieved a remarkable attraction for the capability to transfer power in the long range. We propose two approaches. In the first approach, a 2×4 microstrip patch transmitter antenna array with a high gain and a narrow beamwidth is proposed that is rotated toward the IoT device using a small stepper motor. The performance of the rectifier in the receiving circuit was separately analyzed, and 17.54% efficiency was achieved with a load of 0.6 kΩ for the circuit, while the input power was 10 dBm. The overall system test was performed and the targeted result was investigated considering the distance between the transmitter and the receiver, and an input radio frequency (RF) power of 5 dBm to 15 dBm at 2.4 GHz. The second approach uses a 1×4 transmitter antenna array fed through a Butler matrix to provide four individual beams with a 22.5∘ angular separation, and 90∘ total angular coverage. The goal was to focus the power into four angular locations and to reduce the power waste in other directions. A mobile app was developed to control the direction of the beam. A system efficiency of as much as 19% was measured for an input RF power of 0 dBm and a resistive load of 62 kΩ.
1 citations
30 May 2022
TL;DR: In this paper , a low-profile beamforming antenna array fed by $1\times 4$ Butler matrix and printed on two layers homogeneous stackup substrates for 5G applications in the ka-band is presented.
Abstract: This paper presents a low-profile beamforming antenna array fed by $1\times 4$ Butler matrix and printed on two layers homogeneous stackup substrates for 5G applications in ka-band. The homogeneous stackup substrate is composed of two layers with the same electrical properties. Indeed, the Butler matrix is printed on the lower layer whereas the $4\mathrm{x}4$ Chebyshev tapered microstrip antenna array, is printed on the top one. The overall dimensions are $20\times 27\times 0.63\ mm^{3}$. A switched beam pointing toward four different angles $\pm 4^{\circ}$ and $\pm 29^{\circ}$ is achieved. The corresponding values of the gain are respectively 14.5 dB, 13 dB, 13 dB and 14.5 dB at 28 GHz.
1 citations
References
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Book•
01 Apr 1990
10,459 citations
"Design of a 4×4 butler matrix for b..." refers methods in this paper
...5 shows the geometry adopted for the achievement of this device whose corresponding S matrix [9] – [10] can be written as follows: ...
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...Through evenodd made analysis, it can be shown [9] that the S-matrix is giving as follows....
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TL;DR: In this article, a 4 times 4 two-layer Butler matrix based on a broadband broadband 2-layer slot-coupled directional coupler is presented and implemented at 58 GHz using coplanar waveguide technology.
Abstract: In this paper, a novel 4 times 4 two-layer Butler matrix based on a broad-band two-layer slot-coupled directional coupler is presented and implemented at 58 GHz using coplanar waveguide technology With the slot-coupled directional coupler, the proposed matrix was designed without using any crossovers as used in conventional Butler matrices, which leads to significant size reduction and loss minimization To examine the performance of the proposed matrix, experimental prototypes of the multilayer directional coupler and the Butler matrix were fabricated and measured Furthermore, a four-antenna array was also designed and fabricated at 58 GHz and then connected to the matrix to form a beamforming antenna system As a result, four orthogonal beams at -45deg, -15deg, 15deg, and 45deg are produced Measured results on the entire system agree well with the theoretical predictions, validating the proposed design
133 citations
03 Jul 2005
TL;DR: In this article, a new configuration of a coplanar waveguide (CPW) beamforming 8-port Butler matrix operating at 5.8 GHz is presented, which is based on a novel CPW multilayer directional coupler.
Abstract: In this paper, a new configuration of a coplanar waveguide (CPW) beamforming 8-port Butler matrix operating at 5.8 GHz is presented. This matrix is based on a novel CPW multilayer directional coupler. The main objective of the proposed coupler is to avoid using crossovers as employed in conventional Butler matrices. To examine the performance of the proposed matrix, an experimental prototype was fabricated and measured, and the obtained results confirm the proposed approach.
96 citations
TL;DR: A novel application of 4 $\,\times\,$ 4 Butler matrices in a multiport measurement technique has been investigated in this paper, where the proposed measuring system consists of two standard Butler matrix.
Abstract: A novel application of 4 $\,\times\,$ 4 Butler matrices in a multiport measurement technique has been investigated The proposed measuring system consists of two standard Butler matrices By application of numerical procedure in measurement system calibration, an enhanced accuracy has been achieved An influence of power detectors' uncertainty and imperfect Butler matrix parameters on calibration procedure and measurement results has been investigated The proposed measuring system has been verified by measurements of scattering parameters of two attenuators and a narrowband bandpass filter in frequency range of 2–3 GHz It has been shown that the proposed system allows for achieving results corresponding closely to the measurements obtained with the commercial vector network analyzer
23 citations
"Design of a 4×4 butler matrix for b..." refers background in this paper
...INTRODUCTION Smart antennas are introduced to improve the performance of wireless systems [1] and increase their capacity by spatial filtering, which can separate spectrally and temporally overlapping signals from multiple users....
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01 Dec 2009
TL;DR: In this paper, the design of a microstrip antenna array with four port Butler matrix with switched beam antenna for 2.4GHz band Wi-Fi (Wireless Fidelity) system is presented.
Abstract: In this paper, the design of a microstrip antenna array with four port Butler matrix is presented. The Butler matrix is used as a beamforming network and it produces orthogonal beams that can be steered in different directions. Simulated butler matrix has 10 dB return loss bandwidth of 20%. This matrix feeds four single element microstrip antennas that can be operated from 2.412GHz to 2.484GHz. The circuit is designed by considering a single layer microstrip structure that makes it simpler. The design of wide band microwave devices such as branch-line coupler; cross-coupler and phase-shifters are also incorporated. The switched beam antenna is designed for 2.4GHz band Wi-Fi (Wireless Fidelity) system.
21 citations
"Design of a 4×4 butler matrix for b..." refers background in this paper
...One of the most essential parts of a switched beam antenna system is the feeding of the network [6]....
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