A Reflector Antenna for Focusing Subnanosecond Pulses in the Near Field

Xiao, Shu; Altunc, Serhat; Kumar, Prashanth; Baum, Carl E.; Schoenbach, K.H.

doi:10.1109/lawp.2010.2041027

Cited by 46 publications

(16 citation statements)

References 9 publications

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“…An even newer field of research opens up when the pulse duration is decreased even further, into the subnanosecond range. This push towards further pulse shortening is driven in part by the possibility of using wideband antennas [35], rather than direct contact electrodes. In principle, such techniques would allow better access to biological areas and enable the delivery of electrical energy to deeper lying and inaccessible targets.…”

Section: Discussionmentioning

confidence: 99%

Synergistic effects of local temperature enhancements on cellular responses in the context of high-intensity, ultrashort electric pulses

Song

Joshi

Schoenbach

2011

Med Biol Eng Comput

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Results of self-consistent analyses of cells show the possibility of temperature increases at membranes in response to a single nanosecond, high-voltage pulse, at least over small sections of the membrane. Molecular Dynamics simulations indicate that such a temperature increase could facilitate poration, which is one example of a bio-process at the plasma membrane. Our study thus suggests that the use of repetitive high-intensity voltage pulses could open up possibilities for a host of synergistic bio-responses involving both thermal and electrically driven phenomena.

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Section: Discussionmentioning

confidence: 99%

Synergistic effects of local temperature enhancements on cellular responses in the context of high-intensity, ultrashort electric pulses

Song

Joshi

Schoenbach

2011

Med Biol Eng Comput

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“…IRAs thus provide an attractive means to deliver electrical pulses to induce apoptosis in tissue cells without using needles [6].…”

Section: Psira: a Non-invasive Cancer Treatment Toolmentioning

confidence: 99%

“…In recent years much attention has been paid to the research of impulse radiating antenna, because of the biomedical therapies [6]. A Prolate-Spheroidal Reflector antenna focusing sub-nano second pulsed electromagnetic radiation in the near field is studied [7].…”

Section: Introductionmentioning

confidence: 99%

Design of tapered arm impulse radiating antenna with log periodic lens system for skin cancer treatment

Petrishia

Sasikala

2014

Journal of Medical Engineering & Technology

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A Prolate-Spheroidal Impulse Radiating Antenna (PSIRA) is used as a non-invasive technique for generating an electromagnetic implosion to kill melanoma cells. It can launch and focus fast (100 ps) high voltage (>50 KV) pulses into the biological targets. It can be used to obtain electromagnetic focusing on the target to reduce the damage to the tissue layers surrounding the target (skin). The main aim of this work is to improve the gain of the antenna, enhance the electric field intensity and to reduce the spot size at the focal point. In this work the PSIRA with tapered arm is designed to increase the gain of the antenna. The log periodic lens system is designed to enhance the electric field and reduce the spot size. The IRA with tapered arms located at the position of φ = 60° gives a gain improvement of 14.28% when compared to a traditional IRA. In this work a 10-layer dielectric lens system is designed to match the 100 ps pulses to the skin phantom. Simulation results show that the electric field is increased by a factor of 2. The spot size is reduced from 1 cm to 0.75 cm at the focal point where the target is placed. The proposed Log periodic lens system provides an increase in electric field amplitude and reduction in spot size.

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“…The pulsed power generators of 100 ps-200 ps long, several hundreds of kilovolts in amplitude, have become commercially available (FID Technology). Irradiating such pulses through an antenna can be done using a series of impulse radiating antennas, developed by Baum et al While most of the antennas use parabolic reflectors with an infinity focus, recent efforts were made to send the pulses to the near field target through prolate-spheroidal reflectors [2][3]. In the free space, a prolate-spheroidal reflector focuses the radiation with a lateral focal spot size of 11 cm.…”

Section: Introductionmentioning

confidence: 99%

Simulation of delivery of subnanosecond electric pulses into biological tissues

Xiao

Guo

et al. 2012

2012 IEEE International Power Modulator and High Voltage Conference (IPMHVC)

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Delivery of subnanosecond pulses into biological tissue can be undertaken by an impulse radiating antenna (IRA). Previous analysis shows that it is important to add a dielectric lens, which reduces the abrupt change of dielectric constant from air to tissue and therefore increases the transmission of the pulses. As a proof of concept, we have simulated subnanosecond pulsed radiation focused into a tissue simulant which consists of homogeneous, hemisphere tissues using 3-D electromagnetic solver, CST Microwave Studio. The simulation of an IRA in conjunction of a lens indicates subnanosecond pulses can be focused 6 cm below tissue surface with a spot diameter approximately 1 cm. The focal point coincides with the geometric focus of the IRA. However, this result is only valid for a tissue with a low conductivity (V< 0.3 S/m). For lossier tissues, the electric field decreases from the surface monotonically as the subnanosecond pulses penetrate in depth. Two approaches were proposed to solve this problem. One was to use an inhomogeneous dielectric lens, with lossy material partially filled, to attenuate the incident field in the small azimuthal angles but to spare the field in the larger azimuthal angels. A desirable focusing was observed. The second approach was to use a dipole antenna in conjunction with the impulse radiating antenna. The dipole antenna decreases the surface field intensity generated by the aperture antenna, but at the destination, the field will be mostly given by the aperture antenna, resulting in a focusing.

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A Reflector Antenna for Focusing Subnanosecond Pulses in the Near Field

Cited by 46 publications

References 9 publications

Synergistic effects of local temperature enhancements on cellular responses in the context of high-intensity, ultrashort electric pulses

Synergistic effects of local temperature enhancements on cellular responses in the context of high-intensity, ultrashort electric pulses

Design of tapered arm impulse radiating antenna with log periodic lens system for skin cancer treatment

Simulation of delivery of subnanosecond electric pulses into biological tissues

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