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Circular Array Calculator
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FREQUENCY TO ARRAY RADIUS
NUM ARRAY ELEMENTS
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InstructionsArray sizing must use a spacing multiplier less than 0.5 in order to avoid ambiguities.

However, a smaller radius has less resolving resolution. Ideally you want use a radius with a spacing multiplier close to 0.5. But physical size limitations may take priority.

E.G. If the Rayleigh Super-Resolution is 10 degrees, we can say that the signal source is somewhere within a 10 degree arc.

We consider a resolution of 0 - 25 degrees acceptable for direction finding.		5
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1) Enter desired frequency.
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2) Decide on an appropriate antenna array radius based on physical limitations and desired resolution.
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Desired Freq (MHz)
Wavelength Lambda (Meters)
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434.50.6904487917
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Spacing Multiplier
Interelement Spacing (cm)
Unit RadiusMax Radius (cm)
Est. Resolution (Degrees)
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0.534.522439590.425325404229.37 cm8.217337869
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0.4531.070195630.382792863826.43 cm9.13037541
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0.427.617951670.340260323323.49 cm10.27167234
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0.3524.165707710.297727782920.56 cm11.7390541
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0.320.713463750.255195242517.62 cm13.69556311
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0.2517.261219790.212662702114.68 cm16.43467574
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0.213.808975830.170130161711.75 cm20.54334467
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0.1510.356731880.12759762138.81 cm27.39112623
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0.16.9044879170.085065080845.87 cm41.08668934
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ACCEPTABLE FREQUENCY RANGE FOR A FIXED ARRAY RADIUS
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InstructionsWe consider a resolution of 0 - 25 degrees acceptable for direction finding.

Better resolution will be seen at the higher frequencies, and poorer resolution at the lower frequencies.
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1) Enter array radius
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2) Confirm that your range of interested frequencies is in the green, and at an acceptable resolution for your needs.
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Array Radius (cm)
Interelement Spacing (cm)
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2529.38926261
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Spacing MultiplierFrequency (MHz)Est. Resolution (Degrees)
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0.5510.3904858.217337869
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0.45459.35143659.13037541
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0.4408.31238810.27167234
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0.35357.273339511.7390541
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0.3306.23429113.69556311
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0.25255.195242516.43467574
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0.2204.15619420.54334467
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0.15153.117145527.39112623
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0.1102.07809741.08668934
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ARRAY COORDINATES FOR RADIUS
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Instructions
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1) Enter desired array radius
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2) See X-Y coordinates and graph below for antenna element spacing
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Array RADIUS (cm)
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25
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ANT 0ANT 1ANT 2ANT 3ANT 4
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01234
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X25.00 cm7.73 cm-20.23 cm-20.23 cm7.73 cm
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Y0.00 cm-23.78 cm-14.69 cm14.69 cm23.78 cm
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Bubble Size11111
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NOTE: Graphic shows TOP DOWN View
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ANT 0 points to the forward direction of the array ->
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