As mention in ARRL handbook, for high frequency , the equation for finding element length is :
L = 468 / Fo ( in Feet)
Where Fo = Center Frequency
If We design for 470 - 800 MHz , the center frequency will be Fo = 635 MHz, substitute to the equation :
L = 468 / 635 = 0.737 feet , convert to cm . 1 feet = 30.48 cm , so for 0.737 feet equals to :
L = 0.737 feet x 30.48 cm/feet = 22.46 cm , this is 1/2 lambda for UHF signal in 635 MHZ.
1/4 lambda will be 11.23 cm
As I read in one of literature from S.W. Su and F.S. Chang from Lite On Technology Corporation , Taiwan and Department of Electronics Cheng Shiu University Taiwan. Wideband Rod Dipole Antenna with a modified feed for DTV Signal Reception.
From that literature we can have the design of PCB , feed gap, and dipole design.
I use experiment PCB, and cut the corresponding to the design.The result of antenna as shown .
My design not exactly the same as the design from S.W. Su , i use 1/4 lambda for both arms.
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