a cool waveguide structure design tool

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WR_Connect synthesizes a 20-order tapered corrugated waveguide low-pass (harmonic) filter for 7 seconds. Then it runs 500 frequency points for just 22 seconds naturally computing them one by one (no tricks with so-called "fast", "interpolated" or "adaptive" sweep) 810 times faster than Ansoft HFSS-11. For the same amount of time WR_Connect can give you idea about how TE50-mode, for example, behaves in the filter, which would require even much more time by HFSS...

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WR-62 Receive-Reject Filter

Pass-Band: 17.3 - 18.4 GHz
Insertion Loss: 0.07 dB
Return Loss: 25 dB
Rejection: 90 dB @ 12.75 GHz
Waveguide H-plane Iris Filter
This filter is realized as a sequence of thin full-height diaphragms (windows) in a rectangular waveguide. It is the most old, simple, popular, reliable and manufacturable waveguide band-pass filter solution. The design procedure is simple and well known among filter designers [1,2,3].

WR-75 Transmit-Reject Filter
Pass-Band: 10.7 - 12.75 GHz
Insertion Loss: 0.09 dB
Return Loss: 25 dB
Rejection: 50 dB @ 13.75 - 14.50 GHz
Waveguide E-plane Iris Filter
The filter is realized as a sequence of thin full-width diaphragms (windows) in a rectangular waveguide. This type of structure can be used as a low-pass filter to cut off unwanted spectrum higher than the pass-band. By implementation it is similar to E-plane stub [4] or corrugated filters [5,6,7]. WR_Connect provides templates for the both types as design starting point.

WR-137 Receive-Reject Filter
Pass-Band: 5.85 - 6.45 GHz
Insertion Loss: 0.04 dB
Return Loss: 25 dB
Rejection: 80 dB @ 3.7 - 4.2 GHz
Waveguide Filter with Thick Irises
This filter is a type of H-plane iris filter using thick irises. It is known that iris filters usually demonstrate more rejection at lower roll-off and less rejection of higher frequencies. Increasing thickness of diaphragms would gain the effect and make the frequency response closer to high-pass type.

WR-75 to WR-62 Transition
Pass-Band: 11.0 - 15.0 GHz
Insertion Loss: 0.01 dB
Return Loss: 30 dB
Stepped-Impedance Transformer

WR-Connect provides a template for projecting an exponentially matched transformer for different waveguide interfaces.

WR-75 High-Pass Filter
Pass-Band: 10.0 - 15.0 GHz
Insertion Loss: 0.05 dB
Return Loss: 30 dB
Rejection: 60 dB @ 8.0 GHz
H-plane Stepped Waveguide Filter
Using a cut-off section of waveguide as natural high-pass filter is quite old and still preferable for designers. This filter is based narrow waveguide section matched with interface by two transformers. Using WR-Connect you can design such a filter as simple as a transformer.

WR-112 Corrugated Harmonic Filter
Pass-Band: 7.9 - 8.4 GHz
Insertion Loss: 0.10 dB
Return Loss: 25 dB
65 dB @ 10.5 GHz (roll-off)
80 dB @ 15.8 - 16.8 GHz (2nd harmonic)
80 dB @ 23.7 - 25.2 GHz (3rd harmonic)
60 dB @ 31.6 - 33.6 GHz (4th harmonic)
Tapered Corrugated Low-Pass Filter
Periodically corrugated waveguide filters were originated by Conh [5] and much upgraded to aperiodic tapered structures by Levy [6,7]. The corrugated filters have the best rating among designers because of extreme high power handling, low loss, good match, manufacture reliability and repeatability in comparison with waffle-iron and ridge filters. However they are not much presented in market because of sophisticated spurious theory behind them. Digoria Microwave has previously presented "Corrugated Low-pass Filter Design Workshop", which now is much upgraded with WR-Connect.

WR-112 Band-Pass Filter
Pass-Band: 8.20 - 8.45 GHz
Insertion Loss: 0.15 dB
Return Loss: 25 dB
60 dB @ DC - 7.65 GHz
60 dB @ 9.0 - 18.0 GHz
Composite H-plane / Corrugated Filter

The idea of cascading a band-pass iris filter with a corrugated low-pass filter is not new indeed, however using WR-Connect you could design the cascade as a single unit, make it smaller, less loss and free of spurious spikes caused by propagation of high-order modes.

WR-75 Spurious Suppression Filter
Pass-Band: 11 - 15.0 GHz
Insertion Loss: 0.02 dB
Return Loss: 30 dB
Rejection @ 15-17 GHz:
30 dB TE20-mode
30 dB TE01-mode
TE20 & TE01 Modes Rejection Filter

This waveguide structure is used to reject spurious spectrum carried by TE20 and TE01 modes. It can be used in combination with a conventional cavity filter and gain far-out-of-band rejection with almost no insertion loss increase. Using WR-Connect you can design a filter like this for 50 seconds in three steps (transformer template, transformer synthesis, connection to its Z-flip).


  1. Lewis, W. D., "Wave Filter", US Patent # 2,585,563, 1952
  2. Colling, R. E., "Foundations for Microwave Engineering", McGraw-Hill, New York, 1966.
  3. Mattai, G. L., L.Young, and E. M. T. Jones: "Microwave Filters, Impedance-matching Networks, and Coupling Structures", McGraw-Hill, New York, 1964.
  4. Rhodes, J. D., "Stop-Band Filter", US Patent # 3,845,422, 1974
  5. S.B. Conh "A theoretical and experimental study of a waveguide filter structure", Office Naval Res., Cruft Lab., Harvard Univ., Cambridge, Mass., Rep. 39, Apr. 25, 1948.
  6. Levy, R., "Tapered Corrugated Waveguide Low-Pass Filter", IEEE Trans. Microwave Theory Tech., MTT-21, August 1973, pp. 526-532.
  7. Levy, R., "Aperiodic Tapered Corrugated Waveguide Filter", US Patent 3,597,710, Nov. 28, 1969.