Mi-Wave · mm-wave Attenuators
Variable Attenuators
Every dB under control from K-band to W-band and beyond
Mi-Wave variable attenuators come in three forms: PIN-diode voltage-controlled units, programmable rotary-vane units, and micrometer-driven manual units, between them covering 8 GHz to 325 GHz. Engineers reach for them for automatic gain control, setting power levels in a test chain, and protecting a receiver front end. Each is repeatable and stable in its attenuation, and all use standard waveguide flanges so they drop into mm-wave test systems and automated production test. Evencat is an authorized Mi-Wave distributor in Taiwan.
Overview
The line divides into three families. The 900 Series PIN-diode attenuator is voltage controlled (current datasheets specify 0 to 5 V control on a +8 to 12 V bias) and settles in under 25 ns, which suits fast AGC and ALC loops. The 511 Series programmable rotary-vane attenuator resolves 0.01 dB, spans 0 to 70 dB, and takes GPIB (IEEE-488) or USB commands, so it fits precision lab measurement and automated test. The 510 Series direct-reading attenuator and the 523 Series micrometer-driven attenuator are manual, accurate to about ±0.1 dB, and the economical choice for a bench. All three families use standard waveguide flanges (UG-387/U-M, UG-385/U and so on) and run from X-band at 8.2 GHz to J-band at 325 GHz, which covers satellite, aerospace radar, 5G mm-wave and defense electronics. Each unit is calibrated and tested before shipment and comes with a test report and an outline drawing. Before ordering, decide whether you need speed (900), remote precision (511) or a manual dial (510/523), then check the attenuation range for your band, since range and power rating fall at the top bands.
Key specifications
| Frequency coverage | 8 GHz – 325 GHz (X, K, Ka, Q, U, V, E, W, F, D, G, H and J bands) |
|---|---|
| Attenuation range, PIN-diode type | 0 dB – 30 dB (900 Series; some configurations reach 60 dB isolation) |
| Attenuation range, rotary-vane type | 0 dB – 70 dB (511 Series, 8.2–110 GHz); 0 dB – 40 dB (220–325 GHz) |
| Control voltage, PIN-diode type | 0 – 5 V continuous analog control on current datasheets (0 – 10 V on earlier listings) |
| DC bias, PIN-diode type | +8 V to +12 V, bias current 250 mA |
| Response time, PIN-diode type | < 25 ns |
| Remote interface, 511 Series | GPIB (IEEE-488) / USB; up to 30 programmable addresses |
| Resolution, 511 Series | 0.01 dB per step |
| Endurance, 511 Series | Tested beyond 1,000,000 cycles |
| Power handling, PIN-diode type | 20 dBm typical (900 Series); current datasheets list +23 dBm |
| Waveguide interface | WR-3 to WR-90 (standard UG flanges such as UG-387/U-M, UG-385/U, UG-383/U-M) |
| Power supply, 511 Series | Single +24 VDC |
Features
Continuous voltage control
The 900 Series PIN-diode attenuator sets attenuation smoothly from a control voltage with no moving parts, which gives stable, repeatable behavior in AGC and ALC loops.
Nanosecond response
PIN-diode switching settles in under 25 ns, fast enough for radar pulse control, dynamic tests and receiver protection where the level must change quickly.
0.01 dB steps (511 Series)
The programmable rotary-vane attenuator resolves 0.01 dB and takes GPIB or USB commands, so it drops straight into an automated test system.
8–325 GHz coverage
The families run from X-band to J-band on a consistent set of waveguide flanges, so one architecture serves several bands and integration stays simple.
Built to last
The 511 Series mechanism is tested beyond one million cycles and uses a proprietary absorber for power handling, so measurements stay consistent over years of use.
A family for each job
PIN-diode (900) for fast automatic control, programmable rotary-vane (511) for precision labs, micrometer-driven (523) and direct-reading (510) for manual bench work.
Typical applications
Receiver test
Receiver sensitivity and dynamic range
A variable attenuator ahead of the receiver input steps the RF level down in known increments to find the minimum detectable signal and the noise figure, which is how a 5G mm-wave, satellite or radar transceiver is shown to meet its sensitivity spec. The attenuator spans the dynamic range without swapping hardware and keeps the signal generator out of its nonlinear region.
System calibration
Power references and automated calibration
In a VNA, spectrum analyzer or mm-wave ATE chain, the attenuator sets a precise power reference and makes up for cable and interface loss, so the reference level can be restored to the same point before each run. Calibrated units give a readable attenuation value, and the programmable rotary-vane model runs from a test script with 0.01 dB steps for automated power sweeps.
Front-end protection
Protecting radar and EW front ends
In the transmit/receive timing of an AESA radar or EW system, a PIN-diode voltage-controlled attenuator changes its attenuation within nanoseconds, shielding the LNA and mixer during the high-power transmit pulse while holding a low VSWR and stable match. That keeps the V-band and W-band front end reliable over its service life.
Options and configuration
Choose the model for your band, flange and control method; the selections are collected into a list and carried into the quote form.
Band and waveguide size
Flange
Control method and calibration
Downloads
- 900VF-30/385 datasheetV-band PIN-diode attenuator · Datasheet · PDF
- 900UF-30/383 datasheetU-band PIN-diode attenuator · Datasheet · PDF
- 900VF-30/385 outline drawingOutline Drawing · PDF
- PIN-diode variable attenuators900 Series · miwv.com
- Programmable rotary-vane attenuators (511 Series)511 Series · miwv.com
- Direct-reading precision attenuators (510 Series)510 Series · miwv.com
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