Mi-Wave · Waveguide Couplers
Directional Couplers
Sampling mm-wave power accurately from 18 GHz to 500 GHz
Mi-Wave directional couplers come in E-plane, H-plane, bi-directional, block and crossguide forms, from 18 GHz in K-band to 500 GHz at the edge of the THz range, with coupling values of 3, 6, 10, 20, 30, 40 and 50 dB. Engineers use them to sample the power flowing in a line without disturbing it, or to inject a test signal into a system, in measurement setups, satellite links, radar, EW and 5G/6G infrastructure. All use standard rectangular waveguide with MIL flanges, and their low VSWR and high directivity are what make the sampled reading trustworthy. Evencat is an authorized Mi-Wave distributor in Taiwan.
Overview
The couplers are grouped by construction. The 555 Series bi-directional coupler (18–220 GHz) samples forward and reverse energy at the same time for power monitoring and VSWR measurement. The 559 Series H-plane and 560 Series E-plane broadband couplers cover 18–110 GHz in seven waveguide sizes, use a multi-hole broadwall structure, and give 40 dB directivity with about 1 dB insertion loss. The 561 Series block coupler extends to 500 GHz for THz front-end research. The 564 Series crossguide block coupler is a compact four-port part with two guides crossing at right angles; coupling and directivity are set by the size and position of the coupling apertures, and it is the choice where a small footprint matters more than the highest directivity. The 567 Series dual-directional broadwall coupler (18–110 GHz) is built for measuring incident and reflected power together. Every series offers several coupling values and standard UG flanges, so a lab or production line can pick the value and structure that match the power level and dynamic range in play. Before ordering, check that the coupling value keeps the sampled level inside your detector or analyzer range and that directivity is adequate for the return loss you need to resolve.
Key specifications
| Frequency coverage | 18 GHz – 500 GHz (K, Ka, Q, U, V, E, W, F, D, G, H and J bands plus WR-2.2) |
|---|---|
| Coupling values | 3 dB, 6 dB, 10 dB, 20 dB, 30 dB, 40 dB, 50 dB (by series) |
| Directivity | 40 dB (559 / 560 / 567 Series); 35 dB (561A to 561W); 25 dB (561F to 561(2.2)); 30–35 dB (555 Series) |
| Insertion loss (typical) | 1.0 dB (18–90 GHz); 1.5 dB (90–220 GHz); 6.0 dB (220–500 GHz) |
| Main-line VSWR | 1.05:1 – 1.25:1 (by band and series) |
| Coupling accuracy | ±1.0 dB – ±1.5 dB (by band) |
| Waveguide sizes | WR-42, WR-28, WR-22, WR-19, WR-15, WR-12, WR-10, WR-08, WR-06, WR-05, WR-04, WR-03, WR-2.2 |
| Flanges | UG-595/U, UG-599/U, UG-383/U, UG-385/U, UG-387/U and other MIL standards |
| Main series | 555 (bi-directional), 559 (H-plane), 560 (E-plane), 561 (block), 564 (crossguide), 567 (dual-directional broadwall) |
| Weight (564 Series) | 2–3 oz (by band) |
Features
18 GHz to 500 GHz
From K-band to WR-2.2 waveguide, one product line covers mm-wave and sub-THz measurement without a change of test architecture.
Forward and reverse sampling
The 555 and 567 Series sample incident and reflected energy at once, so system VSWR and return loss can be read directly and the test chain stays simple.
High directivity, low leakage
The multi-hole broadwall structure gives the main series 40 dB directivity, which suppresses the reverse signal and keeps power readings and injected signals accurate.
Seven coupling values
Nominal coupling of 3, 6, 10, 20, 30, 40 or 50 dB lets you match the sampled level to the dynamic range and power of the measurement system.
Five structures
E-plane, H-plane, block, crossguide and bi-directional designs cover everything from broadband measurement to compact integration, for satellite, radar and 5G base-station specs.
Standard waveguide interfaces
MIL-standard UG rectangular flanges throughout, so the couplers mate with existing test equipment and shorten setup time.
Typical applications
RF measurement
VNA calibration and component characterization
In mm-wave development and acceptance testing, a directional coupler in the signal path steers the incident and reflected waves to the reference and measurement ports of a VNA. The engineer obtains S11 and S21 without interrupting the main line, which makes the coupler the sampling element behind amplifier, filter and antenna-port impedance checks.
Satellite communications
Monitoring and protecting Ka-band uplinks
In an earth-station transmit chain, a bi-directional coupler samples forward and reflected power together, so the power-control loop can hold the transmit level within ±0.5 dB. That prevents reflected energy from a mismatch reaching and damaging the HPA, and keeps the carrier from interfering with adjacent satellites.
5G and mm-wave
Source leveling in transmitter module test
When 5G mm-wave (24–40 GHz) power amplifiers and phased-array beamforming modules are verified, a coupler at the amplifier input feeds a power detector or spectrum analyzer that closes a feedback loop on the source. The power delivered to the DUT stays constant, and source drift drops out of the measurement.
Options and configuration
Tick the specifications your application needs; the selections are collected into a list and carried into the quote form.
Series (coupler type)
Band and waveguide size
Coupling value
Downloads
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