scholarly journals An EIRP Measurement Method for Base-Station Antennas Using Field Strengths Measured along a Single Straight Line

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Soon-Soo Oh ◽  
Young-Hwan Lee
Keyword(s):  
Measurement Method ◽  
Phase Retrieval ◽  
Base Station ◽  
Field Pattern ◽  
Far Field ◽  
Single Straight Line ◽  
Base Station Antennas ◽  
Straight Line ◽  
Simple Phase ◽  
Field Strengths

We describe an EIRP measurement technique for a base-station antenna. The proposed method especially can be applied to the base-station antenna installed in real environments. Fresnel region measurement method is an optimal technique to avoid the far-field multipath interference, and, furthermore, it could shorten the measurement time. For detecting only the field strengths along a single straight line, we also propose a simple phase-retrieval method. For verification, a simulation and experiment have been performed. An anechoic chamber was utilized in this paper before the real environment test with the outdoor measurement system. The transformed far-field pattern and EIRP agree closely with the reference data within a valid angle. The proposed method can be applied for the EIRPin situmeasurements without moving a vehicle loading the EIRP measurement apparatus.

scholarly journals Single-Shot Temporal Contrast Enhancement Measurement of a Plasma Mirror by a Chirped Pulse

2021 ◽  
Vol 11 (21) ◽  
pp. 9967
Author(s):  
Dongjun Zhang ◽  
Ping Zhu ◽  
Xinglong Xie ◽  
Yan Liang ◽  
Qingwei Yang ◽  
...  
Keyword(s):  
Contrast Enhancement ◽  
Measurement Method ◽  
Field Pattern ◽  
Single Shot ◽  
Far Field ◽  
Temporal Contrast ◽  
Ccd Cameras ◽  
Chirped Pulse ◽  
Far Field Pattern ◽  
Single Plasma

We focused on a single-shot method for directly measuring the temporal contrast enhancement of a single plasma mirror by analyzing the spectrum of a chirped pulse spatiotemporally overlapped with the igniting laser used for generating a plasma mirror. Experimentally, temporal contrast enhancement of 102 by one plasma mirror was successfully measured in a hundred picosecond timescale and was consistent with the theory. This single-shot measurement method caused no degradation on the performance of the plasma mirror, which was proved by monitoring the efficiency and far-field pattern of the igniting laser after the plasma mirror. Combined with calorimeters and CCD cameras, this method is expected to realize the single-shot online diagnosis of plasma mirrors. This method is expected to be an efficient approach for measuring the temporal contrast enhancement of the plasma mirrors.

scholarly journals Investigation on Wireless Link for Medical Telemetry Including Impedance Matching of Implanted Antennas

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1431
Author(s):  
Ilkyu Kim ◽  
Sun-Gyu Lee ◽  
Yong-Hyun Nam ◽  
Jeong-Hae Lee
Keyword(s):  
Real Time ◽  
Human Body ◽  
Near Field ◽  
Impedance Matching ◽  
The Body ◽  
Field Pattern ◽  
Communication Link ◽  
Far Field ◽  
Antenna Coupling ◽  
Medical Telemetry

The development of biomedical devices benefits patients by offering real-time healthcare. In particular, pacemakers have gained a great deal of attention because they offer opportunities for monitoring the patient’s vitals and biological statics in real time. One of the important factors in realizing real-time body-centric sensing is to establish a robust wireless communication link among the medical devices. In this paper, radio transmission and the optimal characteristics for impedance matching the medical telemetry of an implant are investigated. For radio transmission, an integral coupling formula based on 3D vector far-field patterns was firstly applied to compute the antenna coupling between two antennas placed inside and outside of the body. The formula provides the capability for computing the antenna coupling in the near-field and far-field region. In order to include the effects of human implantation, the far-field pattern was characterized taking into account a sphere enclosing an antenna made of human tissue. Furthermore, the characteristics of impedance matching inside the human body were studied by means of inherent wave impedances of electrical and magnetic dipoles. Here, we demonstrate that the implantation of a magnetic dipole is advantageous because it provides similar impedance characteristics to those of the human body.

Effect of transverse mode structure on the far field pattern of metal-metal terahertz quantum cascade lasers

2008 ◽  
Vol 104 (12) ◽  
pp. 124513 ◽  
Author(s):  
P. Gellie ◽  
W. Maineult ◽  
A. Andronico ◽  
G. Leo ◽  
C. Sirtori ◽  
...  
Keyword(s):  
Quantum Cascade Lasers ◽  
Transverse Mode ◽  
Field Pattern ◽  
Far Field ◽  
Mode Structure ◽  
Quantum Cascade ◽  
Metal Metal ◽  
Far Field Pattern ◽  
Cascade Lasers
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