Showing papers on "Coaxial antenna published in 2020"
Posted Content•
TL;DR: In this article, the authors focus on interstitial microwave hyperthermia, which is a popular medical procedure for treatment of pathological human tissues containing tumors, and compare the models of the coaxial antenna with one, two and three air slots.
Abstract: This study focuses attention on interstitial microwave hyperthermia, which is a popular medical procedure for treatment of pathological human tissues containing tumors. In the paper, the 2D finite element analysis is used to compare the models of the coaxial antenna with one, two and three air slots. The implemented models are based on the wave equation in the TM mode coupled with the Pennes equation under a transient state condition. Moreover, the model takes into account the thermo-electrical properties of human tissue for the antenna operating frequency of 2.45 GHz. Simulation results for different tissues and various multi-slot antenna configurations have been presented. The comparative analysis for single-, double-and triple-slot coaxial antennas shown in this article does not have equivalents in the current literature in the field of hyperthermia.
17 citations
01 Jan 2020
TL;DR: In this article, a simple and precise mono-mode microwave reactor is designed and developed especially for research laboratories, which is able to determine the absorption of microwave power accurately on the heated substance versus a multimode reactor.
Abstract: Mono-mode microwave reactors are usually used to heat substances, especially food. This is because heating using a microwave reactor can sustain the flavor, color, and nutrition of the food. Furthermore, this heating technique is cost-effective and time-saving compared to a conventional heating method. The mono-mode reactor is able to determine the absorption of microwave power accurately on the heated substance versus a multimode reactor. In this chapter, a simple and precise mono-mode microwave reactor is designed and developed especially for research laboratories. The advantage of this reactor is to provide a more accurate calibration process, in order to improve the optimum energy use in the heating process, as well as the temperature of the specimen. The reactor can generate output power from 30 watts to 1500 watts, operating at 2.45±0.03 GHz and capable of accommodating a specimen volume of 780 cm3. Pure water is used as a heated specimen to demonstrate the performance and efficiency of this reactor. Milk Pasteurization and Characterization Using MonoMode Microwave Reactor and Slotted Coaxial Antenna
2 citations
01 Feb 2020
TL;DR: In this paper, a modification of two slots coaxial antenna with a floating sleeve was presented to provide a more spherical heat distribution pattern with low return loss coefficient, which is the best choice to cure hepatic tumors.
Abstract: Microwave ablation (MWA) has been proved its effectiveness in the treatment of hepatic tumors. This tumor is the most common cancer in the world. This paper presents a modification of two slots coaxial antenna with a floating sleeve to provide a more spherical heat distribution pattern with low return loss coefficient. The two slots position, the floating sleeve location, and dimensions are optimized using COMSOL Multiphysics software to achieve the required specifications such as the reflection coefficient, reducing the backward heating pattern, and the heating pattern localization. The spherical heating pattern is the best choice to cure, especially the hepatic tumors. In order to validate the simulation results, the proposed antenna is fabricated and measured. The proposed antenna is fabricated using inexpensive materials. The measured results show that the proposed antenna operated at 2.45 GHz with a reflection coefficient equals -21.16 dB. Also, the measured results have the same trend with the simulated results which proved the antenna design.
1 citations
TL;DR: A very compact permanent magnet 2.45 GHz electron cyclotron resonance ion source has been designed and developed for various purposes and the beam current under different conditions was measured.
Abstract: A very compact permanent magnet 2.45 GHz electron cyclotron resonance ion source has been designed and developed for various purposes. The microwave power is coupled into the plasma chamber using the coaxial antenna instead of the waveguide, the magnetic field is produced by two NdFeB permanent magnet rings, and the diameter of the source body is only 10 cm. The beam current under different conditions was measured. A maximum of 5.8 mA H+/H2+/H3+ mixed beam could be extracted from a 5.5 mm diameter extraction aperture.
1 citations
Patent•
28 Feb 2020
TL;DR: In this article, a conformal antenna device consisting of an antenna shell with a gap antenna interface and a threaded antenna interface is described. But the design of the antenna shell is not discussed.
Abstract: The invention discloses a conformal antenna device. The device comprises an antenna shell, wherein the antenna shell is provided with a gap antenna interface and a threaded antenna interface, the gapantenna interface and the threaded antenna interface are fixedly connected with an external gap antenna assembly and an external threaded antenna assembly respectively, a coaxial antenna body is arranged in the antenna shell, the coaxial antenna body comprises an inner core and an outer conductor, the inner core is coaxially installed in the outer conductor, two ends of the inner core penetrate out of the antenna shell, one end, extending out of the antenna shell, of the inner core is spirally arranged, and the other end, extending out of the antenna shell, of the inner core is communicated with the threaded antenna assembly, and the outer conductor is communicated with the gap antenna assembly. The conformal antenna device is advantaged in that the helical antenna and the gap antenna realize respective energy radiation and absorption by using one coaxial antenna body to perform feed transmission, so the antenna device is small in size and has omnidirectional characteristics in space.
05 Jul 2020
TL;DR: In this article, a liquid metal tunable antenna for microwave ablation that aims to maintain the optimal impedance matching among different organs of treatment was proposed by a pneumatic-driven physical displacement of liquid metal plug inside a dielectric tube interconnecting with the coaxial cable.
Abstract: In this paper, we propose a liquid metal tunable antenna for microwave ablation that aims to maintain the optimal impedance matching among different organs of treatment. Tuning was achieved by a pneumatic-driven physical displacement of liquid metal plug inside a dielectric tube interconnecting with the coaxial cable. Simulations were performed at the operating frequency of 2.45 GHz for the tunable coaxial monopole antenna inserted into models of liver, bone, inflated and deflated lung tissue. We demonstrated that with minor tuning of monopole length, the optimal impedance matching can be achieved among a wide range of dielectric property variations.
01 May 2020
TL;DR: In this article, an improved scheme of the coaxial feed antenna is proposed and the influences of its configuration parameters upon its impedance bandwidth are simulated in order to improve the impedance bandwidth of the antenna, a method of amelioration is proposed.
Abstract: In order to improve the impedance bandwidth of the antenna, a method of amelioration is proposed An improved scheme of the coaxial feed antenna is proposed The influences of its configuration parameters upon its impedance bandwidth are simulated The impendence wide band of the single feed can increase to two-octave and it can gain up to 3dB After scaling, the working frequency band can be changed By nesting the antenna unit in three layers and adjusting the size, the active S11 is less than - 10dB in the range of 0625GHz ~ 5GHz The simulation results show that the coaxial antenna has high performance