Estimating ear canal geometry and eardrum reflection coefficient from ear canal input impedance

Author(s):  
Huiqun Deng ◽  
Jun Yang
2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Janilson L. de Souza ◽  
Karlo Q. da Costa ◽  
Victor Dmitriev ◽  
Felipe Bamberg

This paper presents a broadband nanoantenna fed by a two-wire optical transmission line (OTL). The antenna is defined by a combination of a dipole and a loop, where only the dipole element is connected to the OTL. The analysis is fulfilled by the linear method of moments with equivalent surface impedance to model the conductors. Firstly, the nanoantenna alone is investigated, where the input impedance, current distribution, reflection coefficient, fractional bandwidth, radiation efficiency, and radiation pattern are analyzed. Then, the input impedance matching of this antenna with the OTL is considered. In this case the current, near field distribution, radiation pattern, and reflection coefficient are calculated for different geometrical parameters. The results show that the loop inserted in the circuit can increase the bandwidth up to 42% and decreases the reflection coefficient in the OTL to −25 dB.


2018 ◽  
Vol 7 (3.29) ◽  
pp. 211 ◽  
Author(s):  
Srinivasarao Alluri ◽  
Nakkeeran Rangaswamy

This article presents a super wideband (SWB) circular-shaped fourth iterative fractal antenna loaded with concentric hexagonal slots. A tapered microstrip feed and a partial ground plane is used. It has a total size of 40 × 27 × 1.6 mm3. Numerical results of the antenna show that it provides a bandwidth from 1.43 GHz to more than 40 GHz (percentage bandwidth greater than 186%) with a bandwidth ratio of approximately greater than 28:1 for S11 < -10 dB. A prototype of the proposed antenna has been fabricated and its performances are measured up to 15 GHz. A good agreement is achieved between the numerical and experimental reflection coefficient, VSWR and input impedance. Measured radiation patterns at different frequencies and simulated peak gain are presented and discussed. It has the advantages of super wide bandwidth and compact size. The developed antenna is suitable for various wireless communications such as GPS, GSM, UMTS, ISM and UWB.  


1993 ◽  
Vol 94 (5) ◽  
pp. 2617-2638 ◽  
Author(s):  
Douglas H. Keefe ◽  
Jay C. Bulen ◽  
Kathy Hoberg Arehart ◽  
Edward M. Burns

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