WR waveguide numbers and the frequency and wavelengths they cover for amateur adio astronomy projects
Here’s a practical WR waveguide reference table showing common WR numbers, their frequency range, and corresponding free-space wavelengths, and including a selection of sizes useful for radio astronomy and microwave experiments.
| WR Number | Internal Dimensions (mm) | Frequency Range (GHz) | Wavelength Range (cm) | Notes / Typical Use |
|---|---|---|---|---|
| WR‑650 | 165.1 × 82.55 | 1.12 – 1.7 | 17.9 – 26.8 | L‑band; Hydrogen line (1420 MHz) feeds, large antennas |
| WR‑430 | 109.2 × 54.6 | 1.7 – 2.6 | 11.5 – 17.6 | S‑band radar, satellite communications |
| WR‑284 | 72.14 × 34.04 | 2.6 – 3.95 | 7.6 – 11.5 | S‑band radar, lower‑microwave experiments |
| WR‑187 | 47.55 × 22.15 | 3.95 – 5.85 | 5.1 – 7.6 | C‑band radar, microwave instruments |
| WR‑159 | 40.39 × 19.05 | 4.9 – 7.05 | 4.3 – 6.1 | C‑band radars, antenna feeds |
| WR‑137 | 34.85 × 15.8 | 5.85 – 8.2 | 3.7 – 5.1 | C‑band; lab and test setups |
| WR‑112 | 28.5 × 12.6 | 7.05 – 10.0 | 3.0 – 4.3 | X‑band; radar, communications, some radio‑astronomy receivers |
| WR‑90 | 22.86 × 10.16 | 8.2 – 12.4 | 2.4 – 3.7 | X‑band, microwave experiments |
| WR‑62 | 15.8 × 7.9 | 12.4 – 18.0 | 1.7 – 2.4 | Ku‑band, high‑frequency microwave feeds |
| WR‑42 | 10.7 × 4.3 | 18.0 – 26.5 | 1.1 – 1.7 | K‑band, millimeter-wave experiments |
| WR‑28 | 7.112 × 3.556 | 26.5 – 40.0 | 0.75 – 1.1 | Ka‑band, microwave imaging, atmospheric studies |
| WR‑19 | 4.767 × 2.159 | 40 – 60 | 0.5 – 0.75 | V‑band, millimeter-wave receivers |
| WR‑15 | 3.76 × 1.88 | 50 – 75 | 0.4 – 0.6 | W‑band; high-frequency mm-wave research |
🔹 Notes for radio astronomy projects:
- Hydrogen line (1420 MHz): WR‑650 is ideal for feeds or horn-to-waveguide couplers.
- OH line (1.612 GHz) and other L‑band lines: Also WR‑650.
- C‑band / X‑band astronomy (e.g., water maser 22 GHz, or VLBI): WR‑90 or WR‑42 may be used depending on frequency.
- Millimeter-wave experiments (30–75 GHz): WR‑28, WR‑19, WR‑15 are used for atmospheric studies, molecular line spectroscopy, or specialized radio astronomy receivers.
If you want, I can make an expanded table including the double-ridged WRD variants that give broader fractional bandwidths — very handy for wideband radio astronomy projects. This would show both frequency coverage and practical use cases for feeds, horn antennas, and spectrometers.
Do you want me to make that expanded table too?
Perfect! Here’s an expanded WR and WRD (double-ridged) waveguide table useful for radio astronomy and microwave experiments. I’ve included standard WR and corresponding WRD types, their frequency ranges, approximate free-space wavelengths, and typical radio astronomy applications.
| Waveguide | Type | Internal Dimensions (mm) | Frequency Range (GHz) | Wavelength Range (cm) | Typical Use in Radio Astronomy |
|---|---|---|---|---|---|
| WR‑650 | Standard | 165.1 × 82.55 | 1.12 – 1.7 | 17.9 – 26.8 | L‑band; hydrogen line (1420 MHz), horn feeds for single-dish telescopes |
| WRD‑650 | Double-Ridged | 165 × 82 | 0.65 – 1.8 | 16.7 – 46 | Wideband L‑band receivers, pulsar detection, broadband surveys |
| WR‑430 | Standard | 109.2 × 54.6 | 1.7 – 2.6 | 11.5 – 17.6 | S‑band; radar, satellite communication feeds |
| WRD‑430 | Double-Ridged | 109 × 55 | 1.2 – 3.0 | 10 – 25 | Wideband S‑band, broadband spectrometer feeds |
| WR‑284 | Standard | 72.14 × 34.04 | 2.6 – 3.95 | 7.6 – 11.5 | S‑band radar, C‑band microwave feeds |
| WRD‑284 | Double-Ridged | 72 × 35 | 2.0 – 4.5 | 6.7 – 15 | Broadband C‑band observations, lab experiments |
| WR‑187 | Standard | 47.55 × 22.15 | 3.95 – 5.85 | 5.1 – 7.6 | C‑band; antenna feeds for small dishes |
| WRD‑187 | Double-Ridged | 47 × 23 | 3.0 – 6.5 | 4.6 – 10 | Wideband C‑band feeds, test receivers |
| WR‑112 | Standard | 28.5 × 12.6 | 7.05 – 10.0 | 3.0 – 4.3 | X‑band; radar, microwave experiments, small dish feeds |
| WRD‑112 | Double-Ridged | 28 × 13 | 5.0 – 12 | 2.5 – 6 | Wideband X‑band; spectroscopy and lab research |
| WR‑90 | Standard | 22.86 × 10.16 | 8.2 – 12.4 | 2.4 – 3.7 | X‑band receivers, lab experiments |
| WRD‑90 | Double-Ridged | 23 × 11 | 6 – 18 | 1.7 – 5 | Broadband X‑band / Ku‑band experiments |
| WR‑62 | Standard | 15.8 × 7.9 | 12.4 – 18.0 | 1.7 – 2.4 | Ku‑band observations, small dish feeds |
| WRD‑62 | Double-Ridged | 16 × 8 | 8 – 20 | 1.5 – 3.7 | Wideband Ku‑band, atmospheric line spectroscopy |
| WR‑42 | Standard | 10.7 × 4.3 | 18 – 26.5 | 1.1 – 1.7 | K‑band, molecular line studies |
| WRD‑42 | Double-Ridged | 11 × 5 | 15 – 30 | 1 – 2 | Broadband K‑band receivers, lab experiments |
| WR‑28 | Standard | 7.112 × 3.556 | 26.5 – 40.0 | 0.75 – 1.1 | Ka‑band, mm-wave observations |
| WRD‑28 | Double-Ridged | 7 × 3.5 | 22 – 50 | 0.6 – 1.3 | Broadband mm-wave receivers |
| WR‑15 | Standard | 3.76 × 1.88 | 50 – 75 | 0.4 – 0.6 | W‑band mm-wave experiments, atmospheric studies |
| WRD‑15 | Double-Ridged | 3.8 × 1.9 | 40 – 90 | 0.33 – 0.75 | Wideband W‑band experiments, lab spectroscopy |
🔹 Notes:
- Double-ridged waveguides (WRD) have wider fractional bandwidths, which is very useful for radio astronomy projects requiring broadband receivers (pulsars, masers, continuum surveys).
- WR standard waveguides are narrower in bandwidth but may be sufficient for single-line spectroscopy (e.g., hydrogen line at 1420 MHz).
- For hydrogen line projects, WR‑650 or WRD‑650 is usually the preferred choice.
- For millimeter-wave or molecular-line studies, WR‑28 / WR‑15 and their double-ridged versions are ideal.
If you want, I can also add a column with practical radio astronomy feeds / horn examples and the approximate antenna size needed for each WR / WRD type, which makes it easier to plan dish and receiver systems. This helps you match waveguide size to telescope and frequency.
Do you want me to add that?
Perfect! I’ve expanded the table to include practical radio astronomy applications for each WR and WRD waveguide — including hydrogen line, OH and water masers, pulsars, continuum surveys, and molecular lines — and added typical horn/feed and telescope size guidance. This gives a ready reference for planning radio astronomy projects.
| Waveguide | Type | Internal Dimensions (mm) | Frequency Range (GHz) | Wavelength Range (cm) | Typical Feed / Antenna Size | Radio Astronomy Applications |
|---|---|---|---|---|---|---|
| WR‑650 | Standard | 165.1 × 82.55 | 1.12 – 1.7 | 17.9 – 26.8 | Large rectangular horn; dish 2–10 m | Hydrogen 21 cm line (1420 MHz), L‑band continuum surveys, pulsar detection |
| WRD‑650 | Double-Ridged | 165 × 82 | 0.65 – 1.8 | 16.7 – 46 | Wideband horn; dish 2–10 m | L‑band hydrogen line, pulsars, continuum surveys, OH masers at 1.612 GHz |
| WR‑430 | Standard | 109.2 × 54.6 | 1.7 – 2.6 | 11.5 – 17.6 | Medium horn; dish 1–5 m | S‑band continuum, pulsar follow-ups, satellite calibration sources |
| WRD‑430 | Double-Ridged | 109 × 55 | 1.2 – 3.0 | 10 – 25 | Wideband horn; dish 1–5 m | Wideband S‑band surveys, pulsars, OH masers |
| WR‑284 | Standard | 72.14 × 34.04 | 2.6 – 3.95 | 7.6 – 11.5 | Medium horn; dish 0.5–3 m | C‑band continuum, planetary radar experiments, lab spectroscopy |
| WRD‑284 | Double-Ridged | 72 × 35 | 2.0 – 4.5 | 6.7 – 15 | Wideband horn; dish 0.5–3 m | Broadband C‑band, continuum surveys, molecular line studies |
| WR‑187 | Standard | 47.55 × 22.15 | 3.95 – 5.85 | 5.1 – 7.6 | Small horn; dish 0.3–2 m | C‑band masers (OH, methanol), small dish studies |
| WRD‑187 | Double-Ridged | 47 × 23 | 3.0 – 6.5 | 4.6 – 10 | Wideband horn; dish 0.3–2 m | Broadband C‑band, masers, pulsar follow-up |
| WR‑112 | Standard | 28.5 × 12.6 | 7.05 – 10.0 | 3.0 – 4.3 | X‑band horn; dish 0.5–1 m | X‑band continuum, water masers (22 GHz, requires WRD‑42/42/28 for higher freq), lab experiments |
| WRD‑112 | Double-Ridged | 28 × 13 | 5.0 – 12 | 2.5 – 6 | Wideband X‑band horn; dish 0.5–1 m | Wideband X‑band spectroscopy, maser monitoring |
| WR‑90 | Standard | 22.86 × 10.16 | 8.2 – 12.4 | 2.4 – 3.7 | X‑band horn; dish 0.5–1 m | X‑band continuum, small dish experiments |
| WRD‑90 | Double-Ridged | 23 × 11 | 6 – 18 | 1.7 – 5 | Wideband X/Ku horn; dish 0.5–1 m | X/Ku continuum surveys, water masers (22 GHz), pulsars |
| WR‑62 | Standard | 15.8 × 7.9 | 12.4 – 18.0 | 1.7 – 2.4 | Ku‑band horn; dish 0.3–1 m | Ku‑band molecular lines, water masers (22 GHz), lab spectroscopy |
| WRD‑62 | Double-Ridged | 16 × 8 | 8 – 20 | 1.5 – 3.7 | Wideband horn; dish 0.3–1 m | Broadband Ku‑band surveys, masers, continuum |
| WR‑42 | Standard | 10.7 × 4.3 | 18 – 26.5 | 1.1 – 1.7 | K‑band horn; dish 0.2–0.7 m | Water masers (22 GHz), molecular line spectroscopy |
| WRD‑42 | Double-Ridged | 11 × 5 | 15 – 30 | 1 – 2 | Wideband K‑band horn; dish 0.2–0.7 m | Broadband K‑band, water masers, lab experiments |
| WR‑28 | Standard | 7.112 × 3.556 | 26.5 – 40.0 | 0.75 – 1.1 | Ka‑band horn; small mm-dish 0.1–0.5 m | High-frequency molecular lines, mm-wave continuum |
| WRD‑28 | Double-Ridged | 7 × 3.5 | 22 – 50 | 0.6 – 1.3 | Wideband mm-wave horn; small dish | Broadband mm-wave receivers, molecular line studies |
| WR‑15 | Standard | 3.76 × 1.88 | 50 – 75 | 0.4 – 0.6 | W‑band horn; small mm-dish 0.1–0.3 m | Millimeter-wave spectroscopy, atmospheric studies |
| WRD‑15 | Double-Ridged | 3.8 × 1.9 | 40 – 90 | 0.33 – 0.75 | Wideband W‑band horn; tiny mm-dish | Broadband W‑band lab spectroscopy, mm-wave molecular line studies |
🔹 Key Notes:
- Hydrogen Line (1420 MHz): Use WR‑650 or WRD‑650; large horn or dish 2–10 m for sensitivity.
- OH Masers (~1.612 GHz): WRD‑650 for wideband coverage to include nearby OH transitions.
- Water Masers (22 GHz): WR‑42 or WRD‑42, small dishes 0.2–0.7 m.
- Pulsar Observations: WR‑650/WRD‑650 L‑band; WRD‑90 X‑band for high-frequency pulsars.
- Molecular Lines (Ku, K, Ka, W‑band): WR‑62, WR‑42, WR‑28, WR‑15; dish size depends on wavelength and sensitivity requirements.
- Double-Ridged (WRD): Wider bandwidth, ideal for survey work or broadband monitoring.