Proceedings with Extended Abstracts (single PDF file) - Radio ...

Table 2: Experiment #1 results, Transmission on COCO and Yagi ArraysRX Antenna Array S C /S Y (SNR, dB) S C /S Y (Total Power, dB)COCO / Yagi (RXD) 13.9237 11.1051JRO (RXC) 5.4195 5.6255Table 3: Experiment #2 results, Transmission on JRO ArrayRX Antenna Array S C /S Y (SNR, dB) S C /S Y (Total Power, dB)COCO / Yagi (RXC) 5.9739 5.5257Using the values shown in tables 2 and 3 we can calculate the efficiency ratio betweenthe COCO and Yagi Arrays. If we consider two radar systems that differ only in theirantenna arrays, with areas A Y y A C and efficiencies ε Y y ε C , the ratio of received power S C /S Y isgiven by:SSCYG'G'C C C= (1)YV G'V G'YYThe antenna gain, G, for an ideal antenna is proportional to its area. The real gain G’ iscorrected by an efficiency factor (ε), that takes into account: how good is the illumination ofthe area (ε B ); and any Ohmic loss (ε Ω ).Then, we can write,G' Gε= kAεB ε = kAε(2)= ΩSSCY⎛ G'=⎜⎝ G'CY2⎞ ⎛VC⎟⎜⎠ ⎝ VY⎞ ⎛ εCA⎟ =⎜⎠ ⎝ εYACY2⎞ ⎛VC⎟⎜⎠ ⎝ VY⎞⎟⎠(3)If A has a simple geometry, A ~ Ap; and the dispersion media is aspect sensitive, withsensitivity angles smaller than the antenna beam-width; and we suppose that δ is the angle inthe Y direction; each scattering volume is given by δ and the inverse of the correspondingantenna dimension in the X direction.VYδ= ;LY , XVCδ= (4)LC,XWe can write:SSCY⎛ ε ⎞⎜ε⎟⎝ Y ⎠2⎛ L⎜⎝ LC C , X C,Y Y , X= (5)Y , XLLY , Y⎞⎟⎠2δ Lδ LC,Xand then,⎡⎛εC⎢⎜⎢⎣⎝ εY2⎞ ⎤ ⎡ S⎟ ⎥ = ⎢⎠ ⎥⎦⎣ SCY⎤ ⎡⎛LC⎥ − ⎢⎜⎢⎦ ⎣⎝LY, Y, Y2⎞ ⎤ ⎡ LC⎟ ⎥ −⎢⎠ ⎥⎦⎣ LY, X, X⎤⎥⎦(6)383