Waveguide Sizes

A waveguide is an electromagnetic feed line that is used for high frequency signals. Waveguides conduct microwave energy at lower loss than coaxial cables and are used in microwave communications, radars and other high frequency applications.

The waveguide must have a certain minimum cross section, relative to the wavelength of the signal to function properly. If wavelength of the signal is too long (Frequency is too low) when compared to the cross section of the waveguide, the electromagnetic fields cannot propagate. The lowest frequency range at which a waveguide will operate is where the cross section is large enough to fit one complete wavelength of the signal.

Geometrically speaking there are three types of waveguides – Rectangular Waveguides, Double Rigid Waveguides and Circular Waveguides. The tables below will give you details on the various waveguide sizes and their properties.

Rectangular Waveguide Sizes

Waveguide name Recommended frequency Cutoff frequency
lowest order mode
Cutoff frequency
next mode
Inner dimensions of waveguide opening
EIA RCSC * IEC A inch[mm] B inch[mm]
WR2300 WG0.0 R3 0.32 to 0.45 GHz 0.257 GHz 0.513 GHz 23 [584.2] 11.5 [292.1]
WR2100 WG0 R4 0.35 to 0.50 GHz 0.281 GHz 0.562 GHz 21 [533.4] 10.5 [266.7]
WR1800 WG1 R5 0.45 to 0.63 GHz 0.328 GHz 0.656 GHz 18 [457.2] 9 [228.6]
WR1500 WG2 R6 0.50 to 0.75 GHz 0.393 GHz 0.787 GHz 15 [381] 7.5 [190.5]
WR1150 WG3 R8 0.63 to 0.97 GHz 0.513 GHz 1.026 GHz 11.5 [292.1] 5.75 [146.05]
WR975 WG4 R9 0.75 to 1.15 GHz 0.605 GHz 1.211 GHz 9.75 [247.65] 4.875 [123.825]
WR770 WG5 R12 0.97 to 1.45 GHz 0.766 GHz 1.533 GHz 7.7 [195.58] 3.85 [97.79]
WR650 WG6 R14 1.15 to 1.72 GHz 0.908 GHz 1.816 GHz 6.5 [165.1] 3.25 [82.55]
WR510 WG7 R18 1.45 to 2.20 GHz 1.157 GHz 2.314 GHz 5.1 [129.54] 2.55 [64.77]
WR430 WG8 R22 1.72 to 2.60 GHz 1.372 GHz 2.745 GHz 4.3 [109.22] 2.15 [54.61]
WG9 2.20 to 3.30 GHz 1.686 GHz 3.372 GHz 3.5 [88.9] 1.75 [44.45]
WR340 WG9A R26 2.20 to 3.30 GHz 1.736 GHz 3.471 GHz 3.4 [86.36] 1.7 [43.18]
WR284 WG10 R32 2.60 to 3.95 GHz 2.078 GHz 4.156 GHz 2.84 [72.136] 1.34 [34.036]
WG11 3.30 to 4.90 GHz 2.488 GHz 4.976 GHz 2.372 [60.2488] 1.122 [28.4988]
WR229 WG11A R40 3.30 to 4.90 GHz 2.577 GHz 5.154 GHz 2.29 [58.166] 1.145 [29.083]
WR187 WG12 R48 3.95 to 5.85 GHz 3.153 GHz 6.305 GHz 1.872 [47.5488] 0.872 [22.1488]
WR159 WG13 R58 4.90 to 7.05 GHz 3.712 GHz 7.423 GHz 1.59 [40.386] 0.795 [20.193]
WR137 WG14 R70 5.85 to 8.20 GHz 4.301 GHz 8.603 GHz 1.372 [34.8488] 0.622 [15.7988
WR112 WG15 R84 7.05 to 10 GHz 5.26 GHz 10.52 GHz 1.122 [28.4988] 0.497 [12.6238]
WR102 7.00 to 11 GHz 5.786 GHz 11.571 GHz 1.02 [25.908] 0.51 [12.954]
WR90 WG16 R100 8.20 to 12.40 GHz 6.557 GHz 13.114 GHz 0.9 [22.86] 0.4 [10.16]
WR75 WG17 R120 10.00 to 15 GHz 7.869 GHz 15.737 GHz 0.75 [19.05] 0.375 [9.525]
WR62 WG18 R140 12.40 to 18 GHz 9.488 GHz 18.976 GHz 0.622 [15.7988] 0.311 [7.8994]
WR51 WG19 R180 15.00 to 22 GHz 11.572 GHz 23.143 GHz 0.51 [12.954] 0.255 [6.477]
WR42 WG20 R220 18.00 to 26.50 GHz 14.051 GHz 28.102 GHz 0.42 [10.668] 0.17 [4.318]
WR34 WG21 R260 22.00 to 33 GHz 17.357 GHz 34.715 GHz 0.34 [8.636] 0.17 [4.318]
WR28 WG22 R320 26.50 to 40 GHz 21.077 GHz 42.154 GHz 0.28 [7.112] 0.14 [3.556]
WR22 WG23 R400 33.00 to 50 GHz 26.346 GHz 52.692 GHz 0.224 [5.6896] 0.112 [2.8448]
WR19 WG24 R500 40.00 to 60 GHz 31.391 GHz 62.782 GHz 0.188 [4.7752] 0.094 [2.3876]
WR15 WG25 R620 50.00 to 75 GHz 39.875 GHz 79.75 GHz 0.148 [3.7592] 0.074 [1.8796]
WR12 WG26 R740 60 to 90 GHz 48.373 GHz 96.746 GHz 0.122 [3.0988] 0.061 [1.5494]
WR10 WG27 R900 75 to 110 GHz 59.015 GHz 118.03 GHz 0.1 [2.54] 0.05 [1.27]
WR8 WG28 R1200 90 to 140 GHz 73.768 GHz 147.536 GHz 0.08 [2.032] 0.04 [1.016]
WR6 WG29 R1400 110 to 170 GHz 90.791 GHz 181.583 GHz 0.065 [1.651] 0.0325 [0.8255]
WR7 WG29 R1400 110 to 170 GHz 90.791 GHz 181.583 GHz 0.065 [1.651] 0.0325 [0.8255]
WR5 WG30 R1800 140 to 220 GHz 115.714 GHz 231.429 GHz 0.051 [1.2954] 0.0255 [0.6477]
WR4 WG31 R2200 172 to 260 GHz 137.243 GHz 274.485 GHz 0.043 [1.0922] 0.0215 [0.5461]
WR3 WG32 R2600 220 to 330 GHz 173.571 GHz 347.143 GHz 0.034 [0.8636] 0.017 [0.4318]
    Note:
  • The "WR" designation stands for Rectangular Waveguides
  • The Number that follows "WR" is the width of the waveguide opening in mils, divided by 10. For Example WR-650 means a waveguide whose cross section width is 6500 mils.
  • The waveguide width determines the lower cutoff frequency and is equal (ideally) to ½ wavelength of the lower cutoff frequency.

Double-ridge waveguides are rectangular wagevuides with two ridges protruding parallel to the short wall. This increases the E-Field in the waveguide improving performance.

Double Ridge Waveguide Sizes

Designation
(a)=aluminum, (b)=brass, (c)=copper, (s)=silver
fL - fU*
(GHz)
fCO**
(GHz)
Inside
Width
(in)
Inside
Height
(in)
WR U.S. Mil.
__ /U
British
Mil.
IEC
WR975 RG204 (a)     0.75-1.12 0.605 9.750 4.875
WR770 RG205 (a)     0.96-1.45 0.766 7.700 3.850
WR650 RG69 (b)
RG103 (a)
WG6   1.12-1.70 0.908 6.500 3.250
WR510       1.45-2.20 1.157 5.100 2.550
WR430 RG104 (b)
RG105 (a)
WG8   1.70-2.60 1.372 4.300 2.150
WR340  RG112 (b)
RG113 (a)
WG9A   2.20-3.30 1.736 3.400 1.700
WR284 RG48 (b)
RG75 (a)
WG10   2.60-3.95 2.078 2.840 1.340
WR229  RG340 (c)
RG341 (a)
WG11A R40 3.30-4.90 2.577 2.290 1.145
WR187 RG49 (b)
RG95 (a)
WG12 R48 3.95-5.85- 3.152 1.872 0.872
WR159  RG343 (c)
RG344 (a)
WG13 R58 4.90-7.05 3.712 1.590 0.795
WR137 RG50 (b)
RG106 (a)
WG14 R70 5.850-8.200 4.301 1.372 0.622
WR112 RG51 (b)
RG68 (a)
WG15 R84 7.050-10.000 5.260 1.122 0.497
WR90 RG52 (b)
RG67 (a)
WG16 R100 8.20-12.40 6.56 0.900 0.400
WR75  RG346 (c)
RG347 (a)
WG17   10.0-15.0 7.87 0.750 0.375
WR62 RG91 (b)
RG349 (a)
WG18   12.40-18.00 9.49 0.622 0.311
WR51  RG352 (c)
RG351 (a)
WG19   15.00-22.00 11.6 0.510 0.255
WR42 RG53 (b)
RG121 (a)
WG20   18.00-26.5 14.1 0.420 0.170
WR34 RG354 (c)     20.0-33.0 17.4 0.340 0.170
WR28 RG96 (s)
RG271 (c)
WG22   26.50-40.00 21.1 0.280 0.140
WR22 RG97 (s) WG23   33.00-50.00 26.4 0.224 0.112
WR19   WG24   40.00-60.00 31.4 0.188 0.0940
WR15 RG98 (s) WG25   50.00-75.00 39.9 0.148 0.0740
WR12 RG99 (s) WG26   60.00-90.00 48.4 0.122 0.0610
WR10   WG27   75.00-110.0 59.0 0.100 0.0500
WR8 RG138 (s) WG28   90.00-140.0 73.8 0.0800 0.0400
WR7 RG136 (s)     110.0-170.0 90.8 0.0650 0.0325
WR4 RG137     170.0-260.0 137 0.0430 0.0215
WR3 RG139 (s)     220.0-325.0 174 0.0340 0.0170

Circular Waveguide Sizes

FrequencyBand Frequency Range Circular WaveguideDiameter, Inches (mm) Cover Flange (Brass)MIL-F- 3922 UG Flange Type
X LOW 8.2-9.97 1.094 (27.79) 53-001 UG-39/U Square
MID 8.5-11.6 0.938 (23.83)
HIGH 9.97-12.4 0.797 (20.24)
Ku LOW 12.4-15.9 0.688 (17.48) 53-005 UG-1666/U Square
MID 13.4-18.0 0.594 (15.08)
HIGH 15.9-18.0 0.500 (12.70)
K LOW 17.5-20.5 0.455 (11.56) 54-001 UG-595/U Square
MID 20-24.5 0.396 (10.06)
HIGH 24-26.5 0.328 (8.33)
Ka LOW 26.5-33 0.315 (8.00) 54-003 UG-595/U Square
MID 33-38.5 0.250 (6.35)
HIGH 38.5-40 0.219 (5.56)
Q LOW 33-38.5 0.250 (6.35) 67B-006 UG-383/U Round
MID 38.5-43 0.219 (5.56)
HIGH 43-50 0.188 (4.78)
U LOW 40-43 0.210 (5.33) 67B-007 UG-383/U-M Round
MID 43-50 0.188 (4.78)
HIGH 50-60 0.165 (4.19)
V LOW 50-58 0.165 (4.19) 67B-008 UG-385/U Round
MID 58-68 0.141 (3.58)
HIGH 68-75 0.125 (3.18)
E LOW 60-66 0.136 (3.45) 67B-009 UG-387/U Round
MID 66-82 0.125 (3.18)
HIGH 82-90 0.094 (2.39)
W LOW 75-88 0.112 (2.84) 67B-010 UG-387/U-M Round
HIGH 88-110 0.094 (2.39)
F LOW 90-115 0.089 (2.26) -UG-387/U-M Round
HIGH 115-140 0.075 (1.91)
D LOW 110-140 0.073 (1.85) -UG-387/U-M Round
HIGH 140-160 0.059 (1.50)
G LOW 140-180 0.058 (1.47) -UG-387/U-M Round
HIGH 180-220 0.045 (1.14)
--- --- 170-260 0.049 (1.25) -UG-387/U-M Round
--- --- 220-325 0.039 (0.99) -UG-387/U-M Round