Wideband Feeding Network Research Articles

W-Band Large-Scale High-Gain Planar Integrated Antenna Array

This communication presents a 32 $\,\times\,$ 32 high-gain patch array antenna fed by the substrate integrated waveguide (SIW) structure at W-band. The array antenna consists of two layers to achieve a compact topology, which allows for mass production using a standard PCB fabrication process. The wideband feeding network is placed in the bottom layer while the radiating patches are on the top layer. This configuration also resolves the trade-off between gain and bandwidth of conventional SIW array antennas. Measured gain of the 32 $\,\times\,$ 32 antenna array is within the range 28.81–29.97 dBi in the working bandwidth of 91–97 GHz. Measured impedance bandwidth covers the same frequency band for $\vert {\rm S} _{11} \vert . The cross-polarization of the antenna array is less than 40 dB at the beam direction. Good agreement between the simulated and measured results validates our design.

A programmable compact wide-band RF feed network

The design and fabrication of a wide-band programmable radio frequency (RF) feed network is proposed. It is designed to cover a wide band from 2.5 to 6 GHz over two separate branches. The feed network is simulated and fabricated on an FR-4 substrate with 0.8 mm thickness. Good matching between simulation and measurement results is achieved. The measured amplitude resolution was 0.5 dB with a maximum error of 0.22 dB. The measured phase resolution was approximately 5.6° with 1° maximum error. This design is a generic one that can be used in any kind of RF or antenna systems.

Dual-band Circularly Polarized Aperture Coupled Annular-ring Microstrip Antenna for GNSS Applications

In this paper, a dual-band circularly polarized stacked annular-ring microstrip antenna which covers the bands of Galileo (E5a, E5b, E1, E2, L1), GPS (L1, L2, L5) and GLONASS (L1, L2, L3) is presented. The antenna is composed of two concentric annular-ring patches that are etched on a substrate to generate a dual-band response. Four H-shaped apertures are added to improve the coupling between the microstrip lines and rings. And a wide-band feeding network is used to broaden the axial-ratio bandwidth. Good agreement is achieved between the simulation and measurement, which shows that the return loss of the proposed antenna is less than -15 dB in the whole band and the 3-dB axial-ratio (AR) bandwidths for the lower and upper band are 12.5% and 20.8% respectively. The measured results confirm the validity of the designed antenna which is suitable for Global Navigation Satellite System.

Design of a compact wideband circularly polarized microstrip antenna

abstractA compact wideband feed network comprising a dual‐band Wilkinson power divider and a broadband 90° phase shifter is presented. Taking advantage of the coupled‐line section, the feed network achieves both compact circuit configuration and wideband performance. A compact wideband circularly polarized (CP) antenna using the wideband feed network achieves measured impedance bandwidth (|S11| ≤ –10 dB) of 65%, 3‐dB axial ratio bandwidth of 63%, and peak gain of 8.8 dBi. Above all, the proposed CP antenna features most compact size with the demensions of 0.64 λ0 × 0.64 λ0 × 0.054 λ0 and achieves the trade‐offs between the performance and the demension. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2531–2536, 2013

A Wideband Circularly Polarized Pinwheel-Shaped Planar Monopole Antenna for Wireless Applications

A wideband circularly polarized pinwheel-shaped planar monopole antenna fed by a wideband feeding network is presented in this paper. The proposed antenna is formed by four wideband planar monopole antenna elements with aquadruple feeding network in order to improve the performance of circular polarization. Additionally, the antenna, which is introduced here, has a high gain in the z axis direction because of its folded antenna structure. The attractive characteristics of the proposed antenna are the wide impedance bandwidth of 87.3 % (1 GHz to 2.55 GHz), the 3 dB axial ratio (AR) bandwidth of 92.3 % (1.05 GHz to 2.85 GHz), and the maximum gain within the 3 dB AR bandwidth is about 8.24 dBic.

Optimisation of a microstrip left-handed transmission line using circuit modelling

Two circuit modelling and parameterisation techniques for optimisation of a left-handed microstrip transmission line for antenna applications are presented. Such a transmission line is characterised by high transmission loss ripples in the required frequency band, which hinders its use as a wideband feeding network in antenna array applications. The first circuit modelling technique is based on numerical parameterisation, whereas the second is based on analytical parameterisation. The goal of the parameterisation is to obtain multivariable functions to represent the components of the circuit model with the geometrical dimensions as parameters. A novel and improved circuit model taking into consideration the external mutual coupling between the elements of the left handed transmission line was used to optimise its performance in terms of absolute transmission loss and minimum ripple over a wide frequency band. The performance of the improved equivalent circuit model is compared with the electromagnetic simulations, and a good agreement is obtained. A prototype of the optimised left-handed transmission line was built and tested. Satisfactory agreement was obtained between the simulated and measurement results.

A self-matching wideband feed network for microstrip arrays

A novel technique for feeding microstrip antenna arrays is proposed. It consists of a microstrip feed network designed to operate in dual standing and traveling-wave modes and provide uniform excitation to its elements with either mode. It, therefore, produces a uniform aperture distribution, regardless of the array element input impedances. The traveling wave propagates when radiating elements are matched, but resonant standing wave prevails if loads become mismatched. Since the feed network resonance does not alter the array excitation, it can be used in combination with the radiating patch resonance to broaden the impedance bandwidth. The physical reasons for such behaviors are explained and experimental verification are provided. The generalization of the concept to large arrays is also discussed.