Hi,

I have a design for a Yagi antenna at 436MHz and would like to scale it
to 921 MHz. The calculations I used from the understanding I have
obtained from reading various articles appears below.

Would someone be kind enough to advise me if this procedure and values
look correct ?

Thanks in advance.

The original dimensions(mm) were

Boom = 15 or 20mm square aluminum, 350mm long

Element Length Spacing Diameter
RE 336 0 8
DE 316 80 10
D1 300 190 8
D2 292 330 8

My scaled values to 921MHz
Boom = 12mm x 12mm aluminum 166mm long

Element Length Spacing Diameter
RE 158.9 0 3.78
DE 149.5 38 4.73
D1 141.9 90 3.78
D2 138.2 142 3.78

Now I scaled the tubing to 6mm diameter that I have in stock
Element Length Spacing Diameter
RE 158.5 0 6
DE 148.7 38 6
D1 139.4 90 6
D2 135.3 142 6

Regards

David Huisman