High-gain Dipole Research Articles

Design of Power Dividers for Finite Dipole Subarrays with Complex Impedances

In this study, we propose a method for designing a feeding network for all port-matched and high gain dipole subarray antennas excited by uniform current mode (UCM) by considering the mutual coupling effect. By analyzing the array impedance matrix, we first calculated the active input impedance and the required excitation power. Following this, we transformed and combined the complex impedances using the proposed power divider, thus preserving the required excitation power. The design process and results of this study are demonstrated stepwise through circuit simulation. Subsequently, we fabricated and evaluated the proposed subarrays. The impedance matching performance of the UCM was found to be better than that of the conventional subarray, with their array gains being 11.5 dBi and 9.8 dBi, respectively.

Design of a broadband mode compressed high gain dipole antenna with artificial magnetic conductor as a reflector

Design of a broadband mode compressed high gain dipole antenna with artificial magnetic conductor as a reflector

A Wideband High-Gain Dipole with Impedance and Field Control Structures

Dipoles are favorable in various applications because of their simple and light structure. However, narrow bandwidths and low gain values limit their usage in wideband and long-range systems. To solve this problem, this paper presents a new method to achieve wideband high-gain for dipoles with embedded double-sleeve and a bathtub-shaped cavity. The double-sleeve adjusts the dipole’s impedance and enforces wideband matching from 4.8 GHz to 9.4 GHz. Furthermore, the bathtub-shaped cavity reshapes the antenna’s radiation field and elevates the antenna’s boresight gain to be above 10 dBi in the bandwidth of 5 GHz to 9.4 GHz, which is a 7.75 dBi improvement over the 2.15 dBi gain of conventional dipoles. The combination of the two structures creates a wideband high-gain dipole that features an average simulated boresight realized gain of 11.8 dBi in the impedance bandwidth of 64.8%. Thus, the new antenna can work efficiently in wideband and long-range systems because of its enhanced bandwidth and gain performances.

A miniaturized high gain dipole array antenna for 2.4/5 GHz wireless local area network applications

AbstractA miniaturized high gain dipole array antenna for 2.4/5 GHz wireless local area network (WLAN) applications (2.4‐2.5/5.15‐5.85 GHz) is proposed in this paper. The proposed antenna is composed of a 1 × 3 dipole array, a U‐shaped branch, and a double‐layer feedline. Dual‐band operation is realized by using a double‐branch dipole. The peak gain of the proposed dipole array antenna is improved due to the in‐phase current distributions on dipole elements. A U‐shaped branch is added to further enhance the peak gain in the lower band. For miniaturization, the half‐cutting method is applied. One prototype of the proposed miniaturized antenna with a size of 168 × 10.5 × 0.6 mm3 is manufactured and measured. As a result, the proposed antenna provides the operating bands of 2.30 to 2.59 GHz and 5.10 to 6.73 GHz (voltage standing wave ratio ≤ 2), fully covering 2.4/5 GHz WLAN band. Over the lower/higher band, the peak gain and efficiency are higher than 4.2/5 dBi and 58%/49%, respectively. Furthermore, good omnidirectional radiation characteristic in the horizontal plane is achieved.

All-Around Beam Switched Antenna With Dual Polarization for Drone Communications

This communication presents a drone-to-drone adaptive beam switched antenna with 360° beam coverage and dual polarizations. The proposed antenna maintains the all-around beam coverage with high directivity based on 16 concentric planar Yagi-Uda dipole array. The high gain dipole array beams are configured by eight vertical polarization elements and eight horizontal polarization elements with directors and reflectors. Depending on various communication environments, a single beam, multiple beams with identical polarization, or multiple beams with different polarizations can be adaptively controlled for highly reliable drone-to-drone communication. To ensure the compactness in the antenna array, 16 concentric planar antenna elements are arranged in an orthogonally crossed manner with optimized vertical and horizontal transition matching circuits. Each Yagi-Uda dipole element for vertical or horizontal polarization showed a measured peak gain of 6.35 and 6.40 dBi at 5.5 GHz, respectively. The proposed antenna was integrated with sub-6 GHz transceiver and microcontroller unit (MCU) to verify the switched beam performance with dual polarization. Also, the Tx and Rx operation at random beam conditions was tested by using two proposed antennas and showed an excellent performance from 5 to 6 GHz.

Ultra‐wideband high‐gain dipole antenna evolved from hexagonal Sierpinski grid fractal gasket

Ultra-wideband high-gain dipole antennas are urgently desired for mobile communications. A novel fractal-evolved dipole called modified hexagonal Sierpinski grid carpet dipole, of which size is about 1.5 λ in upper band is developed. With self-similarity and periodicity of fractal geometry, the dipole antenna is excellent in performances. It has an ultra-wide bandwidth and high gain, due to a so-called ‘array effect of element antenna’. It presents a gain as high as 12.7 dBi and stable unidirectional radiation patterns within band of 2.0–3.93 GHz (BW = 65.1%). In addition, the dipole also has good cross-polarisation differentiation, high efficiency, high front-to-back-ratio, small size, low-profile (0.156 λ L ), and light weight. A prototype was fabricated from a plastic body by 3D printing technology and then electroplated on the surface. Then, the sample was measured and compared with simulation results, and good agreements are obtained between them. So, correctness and validity of the design methodology are verified successfully. Due to these remarkable advantages, the fractal antenna is attractive to many radio services, such as mobile communications, defence and military, public security, aeronautics and aerospace, and so on.

High Gain Dipole Antenna with Simple Geometry and Material for Multiband Applications

In general an antenna is act as a transceiver for transmitting and receiving signals with high frequency. It is very important in real time and portable high data rate applications. The parameters decide the characterize of the antenna, the perfectness of antennae are the source resistance of the excitation source that feeds the antennae, characteristic impedance of the transmission line that feeds the antennae, the geometry of the antennae itself, the Voltage Standing Wave Ratio, the Reflection Coefficient, the Directivity, Horizontal Gain, Vertical Gain, Total Gain, radiation pattern, the magnitude of the electric field, efficiency, the current distribution and voltage distribution in the geometry of the antenna. The main parameters to be optimized for wideband portable application are the Gain, Directivity and Efficiency. Dipole antenna transmits the signal in a particular direction only. This work addresses the problem of Gain and Directivity by cascading multiple geometrical structures as well as changing the metal by which the geometrical structure is manufactured. By cascading simple structures it is possible to obtain the same directivity and gain provided by complex structures. The work identifies the second problem of efficiency by using stub or electrical networks as resonators. The stubs are designed by using impedances and admittances information provided by Smith chart at a particular frequency. The tool used for simulation is 4nec2 which stands for Numerical Electromagnetic Code. The frequency of operation used for analysis 300MHz. The wavelength in this frequency of operation is 1m.

High-gain dipole antenna using polydimethylsiloxane–glass microsphere (PDMS-GM) substrate for 5G applications

A new dipole antenna designed using polydimethylsiloxane–glass microsphere (PDMS-GM) substrate is presented. The PDMS-GM substrate offered a lower permittivity of 1.85 compared to pure PDMS of 2.7. This resulted in a wide operating frequency range from 19 GHz up to more than 45 GHz, indicating a bandwidth of more than 28 GHz. The proposed PDMS-GM antenna featured a gain of up to 13.3 dB compared to pure PDMS which only produced 13 GHz of bandwidth and 5.5 dB gain. Instead of wide bandwidth and high gain, the proposed antenna is capable of becoming water resistant by covering its radiator and SMA connector. Such capabilities of the new PDMS-GM antenna indicated suitability for the fifth-generation (5G) wireless communication systems.

A Wideband High-Gain Cavity-Backed Low-Profile Dipole Antenna

In this communication, a compact, wideband, low-profile, and high gain dipole antenna is proposed. A microstrip coupling line is used to feed the ellipse pairs, which is two arms of the antenna. This simple feeding structure can significantly enhance the impedance bandwidth (IBW). A cavity-backed structure is adopted to achieve the low-profile antenna. With the influence of the cavity-backed structure, the new antenna has a higher gain over the whole frequency band. An optimized antenna with a height of only $0.17\lambda $ (where $\lambda $ is the free space wavelength at the lowest frequency) is designed and measured. The measured result shows that the IBW for VSWR $> 6$ dBi) from 2.57 to 8.73 GHz is more than 108.9%. The antenna radiation pattern performs well over the whole band, and the peak gain can reach 11.8 dBi.

Dual-band bidirectional high gain antenna for WLAN 2.4/5.8 GHz applications

A dual-band bidirectional high gain dipole array antenna for WLAN (2.4/5.8 GHz) applications is proposed and analysed. The array antenna is composed of four elements. Each element is a double-sided printed dipole which is fed with a balanced twin transmission line. Measured results agree very well with simulation results. According to the measured results, the bandwidth with a VSWR less than two is about 400 and 1100 MHz in the two bands, respectively. Good shaped patterns are also achieved. The measured gains for the 2.4 and 5.8 GHz bands are between 4.8–6 and 6–8.8 dBi, respectively.

Printed and double‐sided dipole array antennas with a parallel reflector

AbstractThis article describes the novel design of printed and doubled‐sided dipole array antennas with parallel reflector in the application of 2.4 GHz ISM band operated in WiFi access point. The printed dipole array antenna consists of one dipole array arranged back to back and can be easily formed by printing on both sides of a dielectric substrate and is suitable for integration with monolithic microwave integrated circuit (MMIC) module. Based on the matching theory, a 50 Ω microstrip feed line with open stub matched circuits is determined to possess high performance. The all extremely wideband or high gain dipole antenna array for value of standing wave ratio (VSWR) ≤ 1.5 has been successfully implemented and achieved. Simulator IE3D is used to verify our analysis. Both simulated and measured data are much identical. The designed 8‐element printed dipole array antenna without and with a reflector metallic ground plane achieves a gain of 8.5–9.3 dB with a 200 MHz bandwidth and a gain of 11.4–12.3 dB with a 80 MHz bandwidth, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 595–600, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23223