Casio fx-4000P: Antennas
Vertical and Horizontal Bandwidth
Given the height (h) and length (l) of an antenna plate, along with wavelength (λ) given from the antenna, the vertical and horizontal bandwidth, in degrees is calculated as:
Vertical Bandwidth:
ßv = (k * λ * 180) ÷ (h * π)
Horizontal Bandwidth:
ßh = (k * λ * 180) ÷ (l * π) = h * ßv ÷ l
The constant k is the antenna taper factor, which in the original program assigned the constant as k = 1.4.
Casio fx-4000P Program Code (Prog 0)
“HEIGHT” : ? → H :
“LENGTH” : ? → L :
“WAVE. L.” : ? → W :
“VERT-BAND=” ◢
252 × W ÷ H ÷ π → V ◢
“HOR-BAND=” ◢
H × V ÷ L → Z
Example 1:
Input: H: 2.4 ft (height), W: 12.4 ft (width), λ: 0.18 ft (wavelength)
Results:
Vertical Bandwidth: 6.016056849°
Horizontal Bandwidth: 1.1643981°
Example 2:
Input: H: 3.8 ft (height), W: 3.6 ft (width), λ: 0.05 ft (wavelength)
Results:
Vertical Bandwidth: 1.05544857°
Horizontal Bandwidth: 1.114084602°
Convert from Frequency to Wavelength
This program converts frequency (Hz) to wavelength (ft).
λ = c ÷ f
Using
c as the speed of light in a vacuum (299,792,458 m/s), a conversion
is required (1 m ≈ 3.28084 ft).
Casio fx-4000P Program Code (Prog 1)
“FREQ” : ? → F :
“WAVE L.=” ◢
299792458 ÷ F × 3.28084
Example 1:
Input: freq = 6200 MHz (6200E6)
Results: 0.158640498 ft
Example 2:
Input: freq = 8500
Equivalent Antenna Area
The equivalent area given the gain of the antenna in decibels (dB):
Ae = (λ² * 10^(G ÷ 10)) ÷ (4 * π)
Casio fx-4000P Program Code (Prog 2)
“GAIN” : ? → G :
“WAVE L.” : ? → W :
“AREA=” ◢ W² × 10^(G ÷ 10) ÷ 4 ÷ π → A
Example 1:
Input: gain = 28 dB, λ = 0.12 ft
Results: 0.7230238578 ft²
Example 2:
Input: gain = 49 dB, λ = 0.19 ft
Results: 228.1903833 ft²
Source
Hewlett Packard. HP-67/HP-97: Users’ Library Solutions: Antennas. Rev. D April 1979. pp. 32 – 26.
Eddie
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