Physical Limitations of Omni‐Directional Antennas
نویسندگان
چکیده
منابع مشابه
On the Capacity of Wireless Sensor Networks with Omnidirectional Antennas
81 Abstract We establish some new results on the capacity of wireless sensor networks that employ single-userdetection, and we present the implications of our results on the scalability of such networks. In particular, we find bounds on the maximum achievable per-sensor end-to-end throughput, λe, and the maximum number of simultaneously successful wireless transmissions, Nt , under a more gener...
متن کاملPredicting Ground Effects of Omnidirectional Antennas in Wireless Sensor Networks
Omnidirectional antennas are often used for radio frequency (RF) communication in wireless sensor networks (WSNs). Outside noise, electromagnetic interference (EMI), overloaded network traffic, large obstacles (vegetation and buildings), terrain and atmospheric composition, along with climate patterns can degrade signal quality in the form of data packet loss or reduced RF communication range. ...
متن کاملOmnidirectional circularly polarized antennas – a small antenna perspective
1 Abstract—The paper discusses recent developments and challenges in the design of small omnidirectional circularly-polarized (CP) antennas. Although omnidirectional CP coverage is easily achievable using antenna arrays, it is just recently that small and low-cost antennas delivered this functionality. The paper addresses practical design problems for these antennas, not reported in previous pu...
متن کاملPhysical Limitations of Antenna
A discussion of minimum possible antenna quality factor ( ) is first presented in the paper. Based on the spherical wave function theory, the maximum possible ratios of gain to for both directional antenna and omnidirectional antenna are examined and new upper limits for both cases have been obtained. Universally applicable numerical results and some related discussions are also included in the...
متن کاملExcess Physical Limitations Among Adults
RESULTS — People with diabetes had a higher proportion of any physical limitation than did people without diabetes overall (66 vs. 29%, P 0.001), for both men (59 vs. 24%, P 0.001) and women (72 vs. 34%, P 0.001). Compared with those without diabetes, a higher proportion of people with diabetes had some physical limitation among all age groups, and the difference declined (all P 0.001) with inc...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Applied Physics
سال: 1948
ISSN: 0021-8979,1089-7550
DOI: 10.1063/1.1715038