21:I[432972,["/_next/static/chunks/bb923814e1f4d2e9.js","/_next/static/chunks/dd3ee9f5b7716ca6.js","/_next/static/chunks/4204a0ae82542ca8.js","/_next/static/chunks/1270dead247da766.js","/_next/static/chunks/6e1aa89a642f40be.js","/_next/static/chunks/2d7aa753e81324a8.js","/_next/static/chunks/8ffd0b71567920d8.js","/_next/static/chunks/67ea6dfd21f16c5f.js","/_next/static/chunks/24eb4379f68013fd.js","/_next/static/chunks/b8cd775ffdf935bd.js","/_next/static/chunks/983103cd9eb7b428.js","/_next/static/chunks/263f2cdcb9aa2341.js","/_next/static/chunks/294b9525248c8e5f.js"],"default"] 22:T49e,The correlation between signals received by two mobile radio base-station antennas is investigated to determine spacing requirements for space diversity. Measurements of the fading of UHF signals received by two base-station horn antennas oriented at different angles with respect to the incoming mobile radio signal were made for different antenna spacings. The experimental results are compared with an analytical expression derived in this paper; they agree fairly well. A further experiment was made after removing the possible local scatterers surrounding the base station. Comparing these two experimental results, we find that the following are true. 1) Propagation in the direction of a line connecting the two base-station antennas is the critical case and requires a large separation of 70 wavelengths. As soon as the incoming wave is 10° away from the inline axis, the spacing requirement drops to 30 wavelengths. 2) Local scatterers at the base station tend to decrease the correlation between signals received at the two antennas. We conclude that an upper limit to the spacing of antennas used for diversity can be obtained and that it is within the achievable range.23:T546,The effect of mutual coupling on a space diversity combined signal from an optimum resistive load network lessens when the antenna spacing d and the number of elements M increase. When d is greater than 0.2λ, the cumulative distribution curves of an M -branch signal with mutual effects included show only a small difference compared to an array with no coupling, and are close to the cumulative distribution curve of an array with M independent branches. For the average SNR of an array with 100 branches obtained from an optimum resistive load network to be within -3 dB of the SNR from independent branches the required antenna spacing is at least 0.25λ, for an in-line array and 0.5λ, for a planar array. Since a planar array is much smaller than an in-line array for equal performance, the planar array is a more desirable configuration.

#	Concept	H-Index	Publications	Citations
1	Engineering	2	2	348
2	Antenna	2	2	348
3	Wireless Systems	2	2	348
4	Computer Engineering	1	1	17
5	Antenna Design	1	1	331

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