A compact 4 × 4 butler matrix on double‐layer substrate

2016

In the proposed paper, the study of the design of Butler Matrix Elements is presented. The design presented in this paper consists of Microstrip 0 90 Hybrid coupler, 3dB crossover coupler, and 0 45 phase shifter. These elements are designed to work in ISM frequency band i.e. at 2.4GHz, which can be used for wireless applications such as Bluetooth, WLAN, and other wireless applications. The design is implemented on a FR-4 epoxy substrate with dielectric constant of 4 4. r ε = .The design and simulation is carried out in CST studio. Simulated results show good agreement with theoretical calculation.

Wireless Personal Communications, 2014

A design of compact and inexpensive two-layer ultra-wideband (UWB) 4 × 4 butler matrix beam-forming network employing trapezoidal-shaped microstrip-slot technique is presented in this paper. The proposed design uses multi-layer technology that allows having compact size and broad bandwidth. The proposed 4 × 4 butler matrix configuration consists of four couplers and two phase shifters without using crossovers. Both couplers and phase shifters use trapezoidal-shaped broadside coupled patches and a rectangular slot created in a common ground plane of two Rogers duroid RT5880 dielectric substrates. The simulations and experimental results show a good performance in terms of transmission magnitudes and phases with good return losses and isolation characteristics across the entire UWB frequency range. To demonstrate the functionality of the designed butler matrix, four identical tapered slot antenna (TSA) elements are connected to four output ports of the butler matrix and the radiation pattern characteristics are simulated, presented and discussed.

Microwave and Optical Technology Letters, 2009

2015

A design of compact and inexpensive two-layer ultra-wideband (UWB) 4 × 4 butler matrix beam-forming network employing trapezoidal-shaped microstrip-slot technique is presented in this paper. The proposed design uses multi-layer technology that allows having compact size and broad bandwidth. The proposed 4 × 4 butler matrix configuration consists of four couplers and two phase shifters without using crossovers. Both couplers and phase shifters use trapezoidal-shaped broadside coupled patches and a rectangular slot created in a common ground plane of two Rogers duroid RT5880 dielectric substrates. The simulations and experimental results show a good performance in terms of transmission magnitudes and phases with good return losses and isolation characteristics across the entire UWB frequency range. To demonstrate the functionality of the designed butler matrix, four identical tapered slot antenna (TSA) elements are connected to four output ports of the butler matrix and the radiation pattern characteristics are simulated, presented and discussed.

IEEE Access

A novel dual band branch line coupler (BLC) has been proposed, designed, implemented, and analyzed in this paper. A dual band 4 × 4 Butler matrix (BM) has also been developed by employing the proposed BLC. To realize the proposed BLC, PI and modified PI-shaped transmission lines (TLs) as dual band TLs, with the complete derivation of the design equations, have also been introduced. The proposed BLC is equivalent to a dual band ±90 • BLC and a dual band ±45 • phase shifter combination and capable of performing a dual band operation for 2.3 to 4.4 frequency ratios. In order to verify the proposed approach, a dual band BLC for 1GHz and 2.85GHz frequencies has been designed and implemented. For the proposed BLC, equal power division between the output ports has been achieved with maximum ±0.2dB amplitude imbalance and a phase difference of +45 • /−135 • ±1 • at frequency 1GHz and +135 • /−45 • ±2 • at frequency 2.85GHz between the output ports for port1/port4 excitation. By employing the proposed BLC, a dual band 4 × 4 BM has also been developed. Compared to the existing dual band BMs, the 4 X 4 BM offers a simpler design, compact size, and design with fewer number of components. INDEX TERMS Branch line coupler, dual band, Butler matrix, PI shaped transmission line, frequency ratio, compact size.

2012

This paper presents a novel design of a 4 × 4 twolayer wideband Butler matrix using a CB-CPW wideband multilayer directional coupler as well as a novel CB-CPW wideband elliptic directional coupler. With this configuration, the proposed matrix was designed to avoid crossovers as in conventional Butler matrices, thus reducing its size, losses and the design complexity while leading to a broad bandwidth of 3 GHz. To evaluate the performance of the proposed matrix, experimental prototypes of the directional elliptic coupler, the CB-CPW multilayer directional coupler and Butler matrix were fabricated and measured. Furthermore, a 4-element antenna array was connected to the matrix to form a beamforming antenna system at 5.8 GHz. As a result, four orthogonal beams were realized in the band 4.5-7.5 GHz.

IEEE Microwave and Wireless Components Letters, 2015

A novel two-layer 4 4 Butler matrix by feeding substrate integrated waveguide is designed and realized. The proposed Butler matrix has broadband operation frequency range of over 8.5 to 10.6 GHz with excellent phase and amplitude performance. The proposed design in this letter prevents the loss of amplitude and phase shifts in Butler matrix and decreases amplitude imbalance to less than 0.6 dB. This is achieved by reducing the size of Butler matrix and avoiding the use of a line length which causes a phase shift.

2008

A novel design of a compact 4 × 4 Butler matrix is presented. All the design is based on the use of a Lange coupler with certain geometrical characteristics. This matrix occupies only 20% of the size of the conventional Butler matrix at the same frequency (80% of compactness). To examine the performance of the proposed matrix, the Lange coupler and the Butler matrix were simulated using Momentum (ADS) and IE3D softwares. Simulation results of magnitude and phase show a good performance. Furthermore, a four-antenna array was also designed at 2.45 GHz and then connected to the matrix to form a beamforming antenna system. As a result, four orthogonal beams at −45 • , −15 • , 15 • , and 45 • are produced. This matrix is suitable for wireless application at ISM band of 2.45 GHz.

IET Microwaves, Antennas & Propagation, 2008

The design and realisation of a 4 Â 4 Butler matrix for multibeam antenna arrays operating at 5.8 GHz are described. The matrix is implemented on a single layer slotline structure to avoid using air bridges as required in coplanar waveguide technology. In this design, a new hybrid coupler and a crossover using slotline technology were designed and fabricated, and they are used to build a new Butler matrix. To examine the performances of the proposed matrix, numerical simulations and experimental measurements were carried out; the comparison between simulated and experimental results shows a good agreement.

2006

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.