Rectangular Waveguide Sizes

A rectangular waveguide is a hollow conductive metal pipe with a cross section of rectangular shape that guides electromagnetic waves with minimal loss of energy.

The inner dimensions of the waveguide determine the cutoff frequency. The cutoff frequency is the lowest frequency at which the waveguide can operate. In rectangular waveguide, the waveguide width determines the lower cutoff frequency.

The Electronic Industries Alliance (EIA) defined WR designations for standard rectangular waveguides. The designator for a size consists of the letters WR followed by numerals. The letters “WR” stand for Waveguide Rectangular and the number that follows “WR” is the width of the waveguide opening in mils, divided by 10.

The table below gives the details on the various waveguide sizes and their recommended frequency range.

EIA name	Frequency range	Inner dimensions
WR2300	0.32GHz – 0.45GHz	23in × 11.5in
WR2100	0.35GHz – 0.50GHz	21in × 10.5in
WR1800	0.45GHz – 0.63GHz	18in × 9in
WR1500	0.50GHz – 0.75GHz	15in × 7.5in
WR1150	0.63GHz – 0.97GHz	11.5in × 5.75in
WR975	0.75GHz – 1.15GHz	9.75in × 4.875in
WR770	0.97GHz – 1.45GHz	7.7in × 3.85in
WR650	1.15GHz – 1.72GHz	6.5in × 3.25in
WR510	1.45GHz – 2.20GHz	5.1in × 2.55in
WR430	1.72GHz – 2.60GHz	4.3in × 2.15in
WR340	2.20GHz – 3.30GHz	3.4in × 1.7in
WR284	2.60GHz – 3.95GHz	2.84in × 1.34in
WR229	3.30GHz – 4.90GHz	2.29in × 1.145in
WR187	3.95GHz – 5.85GHz	1.872in × 0.872in
WR159	4.90GHz – 7.05GHz	1.59in × 0.795in
WR137	5.85GHz – 8.20GHz	1.372in × 0.622in
WR112	7.05GHz – 10GHz	1.122in × 0.497in
WR102	7.00GHz – 11GHz	1.02in × 0.51in
WR90	8.20GHz – 12.40GHz	0.9in × 0.4in
WR75	10.00GHz – 15GHz	0.75in × 0.375in
WR62	12.40GHz – 18GHz	0.622in × 0.311in
WR51	15.00GHz – 22GHz	0.51in × 0.255in
WR42	18.00GHz – 26.50GHz	0.42in × 0.17in
WR34	22.00GHz – 33GHz	0.34in × 0.17in
WR28	26.50GHz – 40GHz	0.28in × 0.14in
WR22	33.00GHz – 50GHz	0.224in × 0.112in
WR19	40.00GHz – 60GHz	0.188in × 0.094in
WR15	50.00GHz – 75GHz	0.148in × 0.074in
WR12	60GHz – 90GHz	0.122in × 0.061in
WR10	75GHz – 110GHz	0.1in × 0.05in
WR8	90GHz – 140GHz	0.08in × 0.04in
WR6	110GHz – 170GHz	0.065in × 0.0325in
WR7	110GHz – 170GHz	0.065in × 0.0325in
WR5	140GHz – 220GHz	0.051in × 0.0255in
WR4	172GHz – 260GHz	0.043in × 0.0215in
WR3	220GHz – 330GHz	0.034in × 0.017in
WR2	325GHz – 500GHz	0.020in × 0.010in
WR1.5	500GHz – 750GHz	0.0150in × 0.0075in
WR1	750GHz – 1100GHz	0.010in × 0.005in