Mi-Wave · Waveguide Transitions
284 Series Circular to Rectangular Waveguide Transitions
Precision TE10 to TE11 mode transitions from X-band to G-band, VSWR 1.15 across the series
The Mi-Wave 284 Series is a machined mode transition that joins rectangular TE10 waveguide to circular TE11 waveguide. Antenna engineers reach for it when a circular feed or horn has to meet a standard rectangular waveguide chain, from 8.2 GHz up to 220 GHz. Every model in the series holds a VSWR of 1.15, so the transition adds little reflection to the link. Evencat is an authorized Mi-Wave distributor in Taiwan and quotes the full range.
Overview
Each 284 Series transition is machined with a tapered section that converts the rectangular TE10 dominant mode to the circular TE11 dominant mode with a VSWR no worse than 1.15. Fourteen band models run from 8.2 GHz in X-band (WR-90) to 220 GHz in G-band, which covers satellite feeds, radar front ends, aerospace and defense payloads and mm-wave test benches. The rectangular port carries the MIL flange for its band, such as UG-39/U, UG-385 or UG-387/U-M, so the part bolts straight onto existing hardware. The circular port ID is chosen per band: from 0.797 to 1.094 inch in X-band down to 0.049 inch at the top of the range, and the ID is written into the part number as the .XXX field. Material, plating, dimensions, orientation and electrical targets can all be changed to order. Mi-Wave supplies an outline drawing and a test data sheet for each unit, which is what we recommend checking before you fix the mating hardware.
Key specifications
| Product series | 284 Series (circular to rectangular waveguide mode transition) |
|---|---|
| Frequency coverage | 8.2 GHz – 220 GHz (X-band to G-band, by model) |
| VSWR | 1.15 (every model in the series) |
| Mode conversion | Rectangular TE10 mode to circular TE11 mode |
| Models and bands | 284X (8.2–12.4 GHz, WR-90) / 284Ku (12.4–17.5 GHz) / 284K (17.5–26.5 GHz) / 284A (26.5–40 GHz, WR-28) / 284B (33–50 GHz, WR-22) / 284U (40–60 GHz) / 284V (50–75 GHz, WR-15) / 284E (60–90 GHz, WR-12) / 284W (75–110 GHz, WR-10) / 284F (90–140 GHz) / 284D (110–170 GHz) / 284G (125–220 GHz) / 284H (170 GHz) / 284J (140–220 GHz) |
| Circular port ID range | 0.049" (top bands) to 0.797"–1.094" (X-band) |
| Flanges by model | UG-39/U (X-band) / UG-419/U (Ku-band) / UG-595/U (K-band) / UG-599/U (Ka-band) / UG-383 (Q-band) and UG-383/U-M (U-band) / UG-385 (V-band) / UG-387/U and UG-387/U-M (E-band and above) |
| Custom options | Material, plating, dimensions, port orientation and electrical targets can be specified to order; ask us for a quote |
Features
Clean mode conversion
A tapered transition carries the rectangular TE10 mode into the circular TE11 mode with high mode purity, so higher-order modes are kept out of the circular section.
Fourteen bands, one series
Models cover 8.2 GHz to 220 GHz: X, Ku, K, Ka, Q, U, V, E, W, F, D and G bands plus the H and J variants, so one part family serves microwave through sub-THz work.
VSWR 1.15 throughout
No model in the series exceeds a VSWR of 1.15, which keeps reflection at the feed interface low and preserves link budget.
MIL flanges on the rectangular port
Each band ships with its standard UG flange, so the transition mates with antennas, extenders and other waveguide hardware without an extra adapter.
Machined to a specified ID
The circular port bore is machined to the ID you select for the band, and material, plating and orientation can be adapted for the assembly it goes into.
Proven in antenna systems
The series is built for antenna feeds and the components around them, and is in use in satellite links, radar, aerospace, defense and 5G infrastructure.
Typical applications
Satellite communications
Joining satellite feeds to ground-station waveguide
A circular feed such as a prime-focus dish horn delivers a TE11 signal. A 284 Series transition converts it to rectangular TE10 so the feed can meet the LNA, block converter or other WR-size hardware in the ground station. Ka, Ku, Q and V band feed assemblies are the usual fit.
Radar and defense
Mode conversion inside phased-array feed networks
X and Ku band array elements are often circular waveguide to keep the pattern rotationally symmetric. A 284 Series transition ties each element into the rectangular power-divider network and T/R modules while holding a VSWR near 1.15 over the wide temperature and power range that defense hardware sees.
mm-wave measurement
Cabling W, D and G band VNA extenders
Between 75 GHz and 220 GHz, VNA extender heads present rectangular flanges such as UG-387/U-M, while the antenna or probe station under test is often circular waveguide. A 284W, 284D or 284G transition becomes the standard adapter in the measurement chain, so calibration and S-parameter sweeps proceed without a custom fixture.
Options and configuration
Pick the band, rectangular waveguide size and flange you need; the selections are collected into a list and carried into the quote form.
Band and waveguide size
Circular ID (the .XXX suffix)
Flange type
Downloads
Need pricing, specifications or lead time for circular-rect-transition?