Your scaling is not proper. You need to use 50 dB vertically, not 40 per CEA-2034 spec:
"....frequency ratio be equal to 50dB on the vertical scale...."
This is off-topic I've already answered once, but let's try one more time.
I have ANSI/CTA-2034-A R-2020, February 2015. It says:
Data shall be reported in graphical form as illustrated in Figure 4. This chart follows the guidance
of IEC 60263, which stipulates that the horizontal length for a 10:1 frequency ratio be equal to 50
dB on the vertical scale. For the reported data to be useful it is important that the X-Y proportions
and the horizontal and vertical scaling of the graphs be standardized in this manner.
It recommends IEC 60263 aspect ratio of 50 dB/decade. Directivity graph using that spec. would look like this:
My conclusion is that text specification is one of many typos, ambiguities and errors in CTA-2034-A R-2020.
Horizontal scaling is not specified in the text, but Figure 4 has 20-20K (K is Kelvin by the way, and 1000 is k). Y span is 50 dB in Figure 4, and aspect ratio is very close to 25 dB/decade. 25 dB/decade is compatible with IEC 60263 so Figure 4 looks okay.
For example this image has aspect ratio of ca. 32 dB/decade which is not compatible with IEC 60263 and CTA-2034-A R-2020.
I assume that purpose of 50 dB span is to include also extremely bad responses, but normally(/hopefully) it contains huge amount of useless empty space. Common aspect ratio takes care that different products can be compared without using 50 dB span so that magnitude variations look equal, assuming equal width of chart areas.
For example, 30 dB span looks exactly the same as 50 dB span in case aspect ratio is kept 25 dB/decade (/Figure 4) and equal widths:
Aspect ratio is primary spec. imo, maintaining possibility to save vertical space with flat responses and applications or exports including multiple windows which don't need to respect some aspect ratio standard.
