Waveguide & Flange Selection Guide
A few basic facts about waveguide: Here are Waveguide Equations & Fields
- The "WR" designation stands for "waveguide, rectangular"
- The wide inside dimension in inches is the "xxx" part of WRxxx; ie, WR650 is 6.50 inches, WR90 is 0.90 inches.
- The TE10 mode of propagation is the lowest mode that is supported.
- The waveguide width determines the lower cutoff frequency and is equal (ideally) to ½ wavelength of the lower cutoff frequency.
- The TE20, occurs when the width equals one wavelength of the lower cutoff frequency, and so on for higher modes.
- The TE01 mode occurs when the height equals ½ wavelength of the cutoff frequency, and so on to higher modes.
- Click here for waveguide formulas.
| H-Bend | E-Bend |
 An H-Bend is bent in the Hard direction (along the long side). This is the direction of the H-field in the TE10 mode. |  An E-Bend is bent in the Easy direction (along the short side). This is the direction of the E-field in the TE10 mode. |
| Standard Rectangular Waveguide |
Click here for handy free "ezGuide" waveguide selector software from Andrew. |
| 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 | 9.750 | 4.875 | |||
| WR770 | RG205 (a) | 0.96-1.45 | 7.700 | 3.850 | |||
| WR650 | RG69 (b) RG103 (a) | WG6 | 1.12-1.70 | 6.500 | 3.250 | ||
| WR510 | 1.45-2.20 | 5.100 | 2.550 | ||||
| WR430 | RG104 (b) RG105 (a) | WG8 | 1.70-2.60 | 4.300 | 2.150 | ||
| WR340 | RG112 (b) RG113 (a) | WG9A | 2.20-3.30 | 3.400 | 1.700 | ||
| WR284 | RG48 (b) RG75 (a) | WG10 | 2.60-3.95 | 2.08 | 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- | 3.156 | 1.872 | 0.872 |
| WR159 | RG343 (c) RG344 (a) | WG13 | R58 | 4.90-7.05 | 3.705 | 1.590 | 0.795 |
| WR137 | RG50 (b) RG106 (a) | WG14 | R70 | 5.850-8.200 | 4.285 | 1.372 | 0.622 |
| WR112 | RG51 (b) RG68 (a) | WG15 | R84 | 7.050-10.000 | 5.26 | 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 | 7.847 | 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 | 11.54 | 0.510 | 0.255 | |
| WR42 | RG53 (b) RG121 (a) | WG20 | 18.00-26.5 | 14.08 | 0.420 | 0.170 | |
| WR34 | RG354 (c) | 20.0-33.0 | 17.28 | 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 | 0.224 | 0.112 | ||
| WR19 | WG24 | 40.00-60.00 | 0.188 | 0.094 | |||
| WR15 | RG98 (s) | WG25 | 50.00-75.00 | 0.148 | 0.074 | ||
| WR12 | RG99 (s) | WG26 | 60.00-90.00 | 0.122 | .061 | ||
| WR10 | WG27 | 75.00-110.0 | 0.100 | 0.050 | |||
| WR8 | RG138 (s) | WG28 | 90.00-140.0 | 0.080 | 0.040 | ||
| WR7 | RG136 (s) | 110.0-170.0 | 0.065 | 0.0325 | |||
| WR4 | RG137 | 170.0-260.0 | 0.043 | 0.0215 | |||
| WR3 | RG139 (s) | 220.0-325.0 | 0.0340 | 0.0170 | |||
| Double-Ridge Waveguide |
| Double-ridge waveguide provides a wider operational bandwidth at the cost of higher insertion loss and lower power handling. The "D" in WRD stands for double-ridge. D24 at the end means a bandwidth ration of 1.24:1, etc. |
| Designation (a) = aluminum, (b) = brass, (c) = copper | fL - fU (GHz) | fCO (GHz) | Maximum Inside Width (in) | Maximum Inside Height (in) | |
| WRD | U.S. Mil. MIL-W-23351- | ||||
| WRD250 | - | 2.60-7.80 | 2.093 | 1.655 | 0.715 |
| WRD350 D24 | 4-029 (a) 4-303 (b) 4-031 (c) | 3.50-8.20 | 2.915 | 1.480 | 0.688 |
| WRD475 D24 | 4-033 (a) 4-034 (b) 4-035 (c) | 4.75-11.0 | 3.961 | 1.090 | 0.506 |
| WRD500 D36 | 2-025 (a) 2-026 (b) 2-027 (c) | 5.00-18.00 | 4.222 | 0.752 | 0.323 |
| WRD650 | - | 6.50-18.00 | 5.348 | 0.721 | 0.321 |
| WRD750 D24 | 4-037 (a) 4-038 (b) 4-039 (c) | 7.50-18.00 | 6.239 | 0.691 | 0.321 |
| WRD110 D24 | 4-041 (a) 4-042 (b) 4-043 (c) | 11.00-26.50 | 9.363 | 0.471 | 0.219 |
| WRD180 D24 | 4-045 (a) 4-046 (b) 4-047 (c) | 18.00-40.00 | 14.995 | 0.288 | 0.134 |
| North American Waveguide Flange Shapes | IEC Waveguide Flange Shapes | ||||
 Contact Grooved |  CPR |  CMR |  CAR | UDR | UER |
 Square Cover |  Round Cover |  CPR Grooved | UBR | UAR | PDR |
 Choke |  Square Cover Grooved |  Round Cover Grooved | CBR | PBR | PAR |
Flange Style Designations
- UG: UG is the military standard MIL-DTL-3922 for a range of flange types.
- CMR: CMR flanges are the miniature version of the Connector Pressurized Rectangular
(CPR) style flanges. - CPRG: Connector Pressurized Rectangular (CPR) refers to a range of commercial
rectangular flanges. CPRG is Grooved CPR flange. - CPRF: Connector Pressurized Rectangular (CPR) refers to a range of commercial
rectangular flanges. CPRF is flat CPR flange. - Cover or Plate: Square, flat UG style flanges.
- Choke: UG style flanges with an o-ring groove and a choke cavity.
Webmaster: Kirt Blattenberger, BSEE, UVM 1989