01
Main-line transmission
Most RF energy continues through the primary waveguide path while a defined portion is transferred through the coupling apertures.
Broadwall Directional Coupler
A Broadwall Directional Coupler is a microwave network device designed to sample a small portion of the electromagnetic energy in a waveguide system, allowing for precise power monitoring and signal direction without interrupting the main signal flow. It’s essential for accurate diagnostics and system optimization in various RF applications.
Standard Waveguide Component
Multi-hole waveguide directional couplers for sampling forward or reflected microwave power without interrupting the main transmission path. Standard configurations cover 1.13–40 GHz, WR650–WR28, 3–40 dB nominal coupling, waveguide or coaxial coupled ports, and single- or dual-direction monitoring.
Tchebyscheff multi-hole distribution
High directivity
Coupling flatness
Power and reflection monitoring
1.13–40 GHzPublished standard frequency coverage
WR650–WR28R14 through R320 waveguide families
3–40 dBNominal coupling options in the datasheet
20–38 dBMinimum directivity range by configuration
Operating Principle
Controlled directional sampling through the broad wall
The coupler uses a precision-machined Tchebyscheff coupling-hole distribution between the main waveguide and secondary arm. A precision-ground tapered load element terminates the secondary arm. This construction is used to obtain high directivity and stable coupling across the specified band.
02
Directional discrimination
The aperture distribution and secondary-arm termination distinguish energy travelling in the intended direction from energy travelling in the opposite direction.
03
Measured sample output
The sampled signal is delivered through a waveguide or coaxial port for power monitoring, frequency monitoring and reflected-power measurements.
Six Port Arrangements
Select the mechanical interface required by the system
01
3 Waveguide Ports
Single-direction broadwall coupler with two main-line waveguide ports and one waveguide secondary port.
Models: DH-14WC… to DH-320WC…Main-line VSWR: 1.08–1.10 maxSecondary VSWR: 1.12–1.15 maxDirectivity: 20–38 dB min
02
4 Waveguide Ports
Four-waveguide-port arrangement with an unterminated secondary line for external connection or system integration.
Models: DH-26WUC… to DH-320WUC…Main-line VSWR: 1.08–1.10 maxSecondary VSWR: 1.12–1.15 maxDirectivity: 20–38 dB min
03
2 Waveguide Ports + 1 Coax Port
Waveguide through line with one coaxial coupled output. N-Type is listed for lower bands, SMA for higher bands, and 2.92 mm K-type for applicable WR42–WR28 units.
Secondary VSWR: 1.25–1.60 maxDirectivity: 20–38 dB minConnectors: N / SMA / 2.92 mmCoupling: 3–40 dB
04
2 Waveguide Ports + 2 Coax Ports
Waveguide main line with two coaxial secondary ports for a four-port arrangement.
Secondary VSWR: 1.25–1.60 maxDirectivity: 20–25 dB minConnectors: N / SMA / 2.92 mmCoupling: 3–40 dB
05
Dual-arm, 4 Waveguide Ports
Dual-arm broadwall directional coupler for separate forward and reverse waveguide sampling outputs.
Models: DH-26WDXC… to DH-320WDXC…Secondary VSWR: 1.12–1.15 maxDirectivity: 20–38 dB minCoupling: 3–40 dB
06
Dual-arm, 2 Waveguide + 2 Coax Ports
Dual-direction monitoring with two waveguide main-line ports and separate coaxial forward/reverse sample ports.
Secondary VSWR: 1.25–1.50 maxDirectivity: 20–38 dB minConnectors: N / SMA / 2.92 mmCoupling: 3–40 dB
Standard Model Matrix
Waveguide sizes, bands and flange families
The table preserves the published standard model bands. VSWR columns shown here correspond to waveguide-secondary configurations (Styles 1, 2 and 5). Coaxial-secondary configurations use the style-specific values described above.
| Model Prefix | Frequency (GHz) | IEC | EIA | Main VSWR Max | WG Secondary VSWR Max | Published Flange Family | Material |
|---|---|---|---|---|---|---|---|
| DH-14 | 1.13–1.73 | R14 | WR650 | 1.10 | 1.15 | FDP / FDM | Al / Cu |
| DH-18 | 1.45–2.20 | R18 | WR510 | 1.10 | 1.15 | FDP / FDM | Al / Cu |
| DH-22 | 1.72–2.61 | R22 | WR430 | 1.10 | 1.15 | FDP / FDM | Al / Cu |
| DH-26 | 2.17–3.30 | R26 | WR340 | 1.10 | 1.15 | FDP / FDM | Al / Cu |
| DH-32 | 2.60–3.95 | R32 | WR284 | 1.10 | 1.15 | FDP / FDM | Al / Cu |
| DH-40 | 3.22–4.90 | R40 | WR229 | 1.08 | 1.12 | FDP / FDM | Al / Cu |
| DH-48 | 3.94–5.99 | R48 | WR187 | 1.08 | 1.12 | FDP / FDM | Al / Cu |
| DH-58 | 4.64–7.05 | R58 | WR159 | 1.08 | 1.12 | FDP / FDM | Al / Cu |
| DH-70 | 5.38–8.17 | R70 | WR137 | 1.08 | 1.12 | FDP / FDM | Al / Cu |
| DH-84 | 6.57–9.99 | R84 | WR112 | 1.08 | 1.12 | FBP / FBM / FBE | Al / Cu |
| DH-100 | 8.20–12.40 | R100 | WR90 | 1.08 | 1.12 | FBP / FBM / FBE | Al / Cu |
| DH-120 | 9.84–15.0 | R120 | WR75 | 1.08 | 1.12 | FBP / FBM / FBE | Al / Cu |
| DH-140 | 11.9–18.0 | R140 | WR62 | 1.10 | 1.15 | FBP / FBM / FBE | Al / Cu |
| DH-180 | 14.5–22.0 | R180 | WR51 | 1.10 | 1.15 | FBP / FBM / FBE | Al / Cu |
| DH-220 | 17.6–26.7 | R220 | WR42 | 1.10 | 1.15 | FBP / FBM / FBE | Al / Cu |
| DH-260 | 21.7–33.0 | R260 | WR34 | 1.10 | 1.15 | FBP / FBM / FBE | Al / Cu |
| DH-320 | 26.3–40.0 | R320 | WR28 | 1.10 | 1.15 | FBP / FBM / FBE | Al / Cu |
Datasheet notes: nominal coupling accuracy ±0.7 dB; frequency sensitivity ±1 dB; coupling range 3–40 dB; material Al/Cu; multiple flange types are available; standard finish is corrosion protection plus black top coat.
Selection Workflow
Information required for model review
1
Define the RF band
Provide the operating frequency range and the corresponding IEC or EIA waveguide size.
2
Select directionality
Choose one sampled direction or separate forward and reverse sampled outputs.
3
Specify interfaces
Confirm waveguide or coaxial coupled ports, connector type and main-line flange arrangement.
4
Confirm mechanical details
Provide material, finish, drawing constraints, quantity and any special configuration requirements.
Construction & Finish
Published manufacturing and ordering details
01
Precision-machined apertures
Tchebyscheff coupling-hole distribution is used to support directivity and coupling flatness.
02
Secondary-arm load
A precision-ground tapered load element is used in the terminated secondary arm.
03
Material choices
The specification tables list aluminum and copper. The product page also describes oxygen-free hard copper or copper-alloy construction.
04
Standard finish
Corrosion-protection treatment plus black top coat. Other finishes or mechanical arrangements can be reviewed on request.
Applications
Typical integration environments
Power and reflection measurement
Sampling incident or reflected energy in test setups, transmitter chains and waveguide assemblies.
Radar and defence systems
Directional monitoring and diagnostic sampling within qualified radar and defence microwave subsystems.
Satellite communications
Signal and power sampling in uplink, downlink, earth-station and antenna-feed waveguide networks.
Telecommunications
Monitoring microwave transmission paths without removing the primary signal from service.
Research and laboratory systems
Frequency monitoring, reflected-power evaluation and experimental microwave measurements.
Custom waveguide assemblies
Integration into larger waveguide runs where port orientation, flange type or mechanical envelope must match an existing system.
Technical Resources
Official product documents and waveguide references
PDF DatasheetBroadwall Directional Coupler Specification
Eight-page specification covering six port arrangements, model tables, accuracy, sensitivity, connector notes and ordering information.
Technical ReferenceWaveguide Flange Standard EIA & IECReview the flange designation system used when selecting mating interfaces.
Product CategoryStandard Waveguide ComponentsBrowse related standard waveguide products for a complete RF transmission assembly.
Related Products
Components commonly reviewed with directional couplers
Alternative CouplerCrossguide Directional Couplers
Compact crossguide sampling arrangements with waveguide and coaxial port options.
Alternative CouplerWaveguide Loop CouplerLoop-coupled configurations for applications requiring a different coupling structure.
Alternative CouplerWaveguide Probe CouplerProbe-based sample-port configurations for selected waveguide systems.
System IntegrationWaveguide-to-Coaxial AdaptersConnect waveguide runs to coaxial instruments, cables and RF equipment.
System IntegrationWaveguide TerminationsMatched terminations for unused ports, measurement setups and waveguide assemblies.
System IntegrationFlexible WaveguideFlexible routing sections for alignment, installation and vibration accommodation.
Engineering Articles
Additional directional-coupler reading
Material SelectionWhat Is the Material of a Directional Coupler?
Background on how conductor, substrate and mechanical material choices influence RF performance.
Coupling StructureHow Many Holes Can Be Used in a Directional Coupler?An introduction to coupling apertures and the difference between physical ports and coupling holes.
Component ComparisonDirectional Couplers vs. TapsCompare directional signal sampling with non-directional signal division.
FAQ
Broadwall directional coupler questions
What is the standard frequency range?
The published standard product line covers 1.13–40 GHz, corresponding to WR650 through WR28. Additional sizes or special configurations are available for review on request.
What coupling values are available?
The product datasheet lists a nominal coupling range of 3–40 dB. The website identifies common values including 3, 6, 10, 20, 30 and 40 dB. Confirm the required value and operating band when requesting a model.
What is the difference between WC, WUC and WDXC configurations?
WC identifies single-arm broadwall configurations in the datasheet. WUC is used for four-port secondary-line arrangements. WDXC identifies dual-arm configurations for separate forward and reverse sampling.
Are waveguide and coaxial coupled outputs available?
Yes. The six published styles include waveguide secondary ports and coaxial secondary ports. Listed coaxial interfaces include N-Type, SMA and 2.92 mm K-type according to waveguide band and configuration.
What directivity should be used for system calculations?
Use the value for the selected port style and model. Waveguide-secondary and single-coax configurations list up to 20–38 dB minimum, while the two-coax four-port Style 4 lists 20–25 dB minimum.
What coupling accuracy and frequency sensitivity are published?
The datasheet states nominal coupling accuracy of ±0.7 dB and frequency sensitivity of ±1 dB.
Which materials and finishes are available?
The specification tables list aluminum and copper. The product page also references oxygen-free hard copper or copper alloy. The standard ordering note states corrosion protection plus a black top coat.
What information should be included with an RFQ?
Provide frequency range, waveguide size, required coupling, single- or dual-direction monitoring, coupled-port interface, connector and flange types, material, mechanical drawing or envelope, quantity and any environmental or documentation requirements.
Model Review
Send the operating band and interface requirements
For technical review, include the frequency range, waveguide size, coupling value, port arrangement, connector, flange, material, mechanical constraints and quantity.
Contact Dolph Microwave sales@dolphmicrowave.com +86 29 8881 0979
