Waveguide Specs.

WG #	EIA #	IEC #	Low Freq.	High Freq.	Cutoff Freq.	Internal Size (mm)	Wall
WG10	WR284	R32	2.60GHz	3.95GHz	2.078GHz	72.14 34.04	2.032
WG11					2.448GHz	60.25 28.50	1.626
WG11A	WR229	R40	3.30GHz	4.90GHz	2.577GHz	58.17 29.08	1.626
WG12	WR187	R48	3.95GHz	5.85GHz	3.152GHz	47.55 22.15	1.626
WG13	WR159	R58	4.90GHz	7.05GHz	3.711GHz	40.39 20.19	1.626
WG14	WR137	R70	5.85GHz	8.20GHz	4.301GHz	34.85 15.80	1.626
WG15	WR112	R84	7.05GHz	10.0GHz	5.260GHz	28.50 12.62	1.626
OLD English					5.902GHz	25.40 12.70
WG16	WR90	R100	8.20GHz	12.4GHz	6.557GHz	22.86 10.16	1.270
WG17	WR75	R120	10.0GHz	15.0GHz	7.869GHz	19.05 9.525	1.270
WG18	WR62	R140	12.4GHz	18.0GHz	9.488GHz	15.80 7.899	1.016
WG19	WR51	R180	15.0GHz	22.0GHz	11.57GHz	12.95 6.477	1.016
WG20	WR42	R220	18.0GHz	26.5GHz	14.05GHz	10.67 4.318	1.016
WG21	WR34	R260	22.0GHz	33.0GHz	17.36GHz	8.636 4.318	1.016
WG22	WR28	R320	26.5GHz	40.0GHz	21.08GHz	7.112 3.556	1.016
WG23	WR22	R400	33.0GHz	50.0GHz	26.34GHz	5.690 2.845	1.016
WG24	WR19	R500	40.0GHz	60.0GHz	31.39GHz	4.775 2.388	1.016

IEC - International Electrotechnical Commission,
EIA - Electronic Industries Association (USA).

Microwave Band Designators 

Standard Radar Frequency Letter-Band Nomenclature(IEEE Standard 521-1984)
Band Designator	Frequency (GHz)	Wavelength in Free Space (centimeters)
L band	1 to 2	30.0 to 15.0
S band	2 to 4	15 to 7.5
C band	4 to 8	7.5 to 3.8
X band	8 to 12	3.8 to 2.5
Ku band	12 to 18	2.5 to 1.7
K band	18 to 27	1.7 to 1.1
Ka band	27 to 40	1.1 to 0.75
V band	40 to 75	0.75 to 0.40
W band	75 to 110	0.40 to 0.27