Bandwidth Enhancement of a Planar Printed Quasi-Yagi Antenna With Size Reduction

Wu, Jheng-Yu; Zhao, Zhiqin; Nie, Zaiping; Liu, Qing

doi:10.1109/tap.2013.2287286

Cited by 108 publications

(74 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Reducing the lateral size of the ground plane will decrease the electrical size of the ground plane, in order to remedy the defect, two stubs are symmetrical extended from its ground plane [14]. Figure 7 shows the reflection coefficient varying with different length (L 5 ) of the stub.…”

Section: Antenna Design and Discussionmentioning

confidence: 99%

“…A notched band from 4.8 GHz to 6.1 GHz is implemented by L-shape slot etched on the driver dipole element. Gain is significantly improved by rotating the driver dipole and two parasitic strips compared with the antenna in [14]. Good experimental results indicate that this antenna has good performance.…”

mentioning

confidence: 95%

“…Compared with conventional quasi-Yagi antennas, the proposed antenna lateral size is reduced by symmetrically adding two stubs on the ground [14]. A notched band from 4.8 GHz to 6.1 GHz is implemented by L-shape slot etched on the driver dipole element.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Wideband Planar Printed Quasi-Yagi Antenna With Band-Notched Characteristic

Zhang¹,

Tang²,

Yin³

2014

PIER Letters

View full text Add to dashboard Cite

Abstract-A wideband planar printed quasi-Yagi antenna with band-notched characteristic is presented. The proposed antenna consists of a microstrip-to-slotline transition structure, a gradient driver dipole, and two parasitic strips as directors. Meanwhile, the arms of the driver and two directors are rotated in a certain angle to improve the gain. To avoid the frequency interference from WLAN operating in the frequency band from 5.15 GHz to 5.825 GHz, an L-shape slot etched on the driver dipole is adopted to achieve a notched band ranging from 4.8 GHz to 6.1 GHz. The ground plane is symmetrically added two stubs to implement the lateral size reduction. The measured bandwidth, determined by the reflection coefficient less than −10 dB, covers from 3 GHz to 10.8 GHz. Better than 8.1 dB F/B ratio and the measured antenna gain varying between 4.7 and 8.3 dBi are also achieved in the operating bandwidth excepting in the notched band.

show abstract

Section: Antenna Design and Discussionmentioning

confidence: 99%

mentioning

confidence: 95%

See 1 more Smart Citation

Wideband Planar Printed Quasi-Yagi Antenna With Band-Notched Characteristic

Zhang¹,

Tang²,

Yin³

2014

PIER Letters

View full text Add to dashboard Cite

show abstract

“…Therefore, speeding up a re-design process by re-using one or more existing designs seems to be an attractive alternative. Notwithstanding, it is a challenging task: due to complexity of contemporary antennas [12], the relationships between geometry parameters [13] and performance figures are normally nonlinear and often counter-intuitive (e.g., some of the parameters may increase, whereas others decrease when the substrate permittivity is increased).…”

Section: Introductionmentioning

confidence: 99%

On Rapid Re-Design of UWB Antennas with Respect to Substrate Permittivity

Koziel

Bekasiewicz

2016

Metrology and Measurement Systems

View full text Add to dashboard Cite

Re-design of a given antenna structure for various substrates is a practically important issue yet non trivial, particularly for wideband and ultra-wideband antennas. In this work, a technique for expedited redesign of ultra-wideband antennas for various substrates is presented. The proposed approach is based on inverse surrogate modeling with the scaling model constructed for several reference designs that are optimized for selected values of the substrate permittivity. The surrogate is set up at the level of coarse-discretization EM simulation model of the antenna and, subsequently, corrected to provide prediction at the high-fidelity EM model level. The dimensions of the antenna scaled to any substrate permittivity within the region of validity of the surrogate are obtained instantly, without any additional EM simulation necessary. The proposed approach is demonstrated using an ultra-wideband monopole with the permittivity scaling range from 2.2 to 4.5. Numerical validation is supported by physical measurements of the fabricated prototypes of the re-designed antennas.

show abstract

“…Despite the excellent impedance matching or unidirectional radiation achieved by the aforementioned designs, there are still several major obstacles in applying them for practical portable wireless applications. Those obstacles include using bulky three-dimensional (3-D) structures [103], [104], [105], [98], large planar dimensions [106]- [108], having narrow operational bandwidth [102], complicated fabrication process [97]- [100] or unstable gain [101], [42].…”

Section: Introductionmentioning

confidence: 99%

Wideband Microwave Imaging Systems for the Diagnosis of Fluid Accumulation in the Human Torso

Rezaeieh¹

View full text Add to dashboard Cite

According to the World Health Organization (WHO), cardiovascular diseases (CVDs) are the leading causes of death worldwide, with one third of deaths attributed to CVDs in 2012. Pulmonary oedema and pleural effusion are the most apparent symptoms of many diseases categorized under CVDs such as heart failure and lung cancer, at which fluid (mainly with high water content) is accumulated in or around the lungs. Therefore, constant monitoring of fluid levels inside the lungs is one of the most efficient ways of early detection of CVDs. Chest X-Rays and computational tomography (CT)-scans are the most widely used devices for fluid detection; however, they suffer from lack of sensitivity and ionizing radiation, respectively, that makes them unsuitable for long term monitoring purposes. Currently, magnetic resonance imaging (MRI) is the most reliable device that can be utilized for fluid accumulation detection. However, considering the fact that more than 75% of the CVDs occur in countries with low or middle income, it is not widely available. Moreover, due to their bulky structures, the abovementioned devices lack the capability of being used in mobile emergency units such as ambulances or clinics at rural areas. To that end, this thesis is dedicated to design and fabrication of a low cost, portable and non-invasive device that can be used as an initial decision making tool for medical staff to pursue further investigations to define the exact cause of the oedema.First chapter of the thesis is allocated to introduction of the cardiovascular diseases and their effects on the dielectric properties of the tissues inside the lungs. A complete literature review on various alternative methods for replacing the conventional devices is performed. The obtained results by these systems and their advantages as well as their limitations are discussed. Microwave imaging technique is then presented in chapter two as a robust method which can both provide information about the presence and location of the accumulated fluid. This is specifically of great importance for cases where biopsy is required to remove or take sample of the accumulated fluid for saving the life of the patient. Chapter two is also allocated to the introduction of microwave-based medical diagnostic and monitoring systems for different applications such as breast cancer detection and brain imaging. A prospect of the possible realizable systems is investigated and existing scanning approaches are discussed. The main contributions of the thesis that are the design of several complete platforms, design of novel and unidirectional microwave sensors (antennas), promotion of novel scanning and detection methods are clarified in these chapters.In chapter three, firstly the optimum operating frequency for torso imaging is defined. By applying a circuit model that models different layers of torso as circuit elements, it is shown that a wide operating bandwidth at lower ultra-high frequency (UHF) band provides a reasonable III compensation between the resolution of...

show abstract

Bandwidth Enhancement of a Planar Printed Quasi-Yagi Antenna With Size Reduction

Cited by 108 publications

References 16 publications

Wideband Planar Printed Quasi-Yagi Antenna With Band-Notched Characteristic

Wideband Planar Printed Quasi-Yagi Antenna With Band-Notched Characteristic

On Rapid Re-Design of UWB Antennas with Respect to Substrate Permittivity

Wideband Microwave Imaging Systems for the Diagnosis of Fluid Accumulation in the Human Torso

Contact Info

Product

Resources

About