Free Space Measurement Systems

Microwave Measurement Systems offers a superior approach to microwave and millimeter wave measurement. Where traditionally the electromagnetic properties of materials have been measured with waveguide, coaxial, or cavity resonance methods, MMS Free Space Measurement Systems is contactless and nondestructive.

Manual Freespace System

Spot focused antennas in microwave and mm-wave frequencies (5.8-110 GHz) are attached to micrometer-driven carriages for position adjustment. The carriages rotate about the central sample holder, allowing bistatic and oblique incidence measurements. The Vector Network Analyzer can be controlled by your computer and data acquisition software will export the data to the analysis software. Software can be customized to meet your needs.

The Free Space System is available as a manually operated tabletop model that can upgraded to the Automated Freespace System.

MMS Automated Free Space Measurement System

An upgraded version of the manual Freespace Measurement System removes error introduced by the user in the measurement process.

  • Achieve extreme precision with nine servo controlled degrees of freedom. There are two linear (x, z) and two rotary axes (theta, phi) for each spot focused horn antenna and one linear positioner (y) for the sample holder.
  • Automatically scan and characterize electromagnetic materials such as dielectrics, RAM, metamaterials, and shielding materials over a large area.
  • Scan objects up to 36" x 12" or scan over arbitrarily shaped objects from user-defined coordinates.
  • Conduct automated bistatic and oblique incidence measurements of object under test.
  • Take automated measurements as a function of polarization angle.
  • Customize for specific applications.


The magnitude and phase errors after full TRL calibration of the reflection coefficients are less than 0.4 dB and ±2 degrees respectively. For the transmission coefficient, the amplitude and phase errors are less than ± 0.2 dB and ± 2 degrees, respectively.


MMS will custom design the Free Space System for your application and requirements, including specific environmental requirements. Motion control can be designed and integrated to enable automated scanning as required. Please contact our engineers with your requirements and specifications for a quote.


Frequency Range:

8.2 - 12.4 GHz (Base System) optionally expandable to 5.85 - 110 GHz

Operation Temperatures:

-40° C to 1500° C with optional furnaces

Bistatic Angles:

37° to 65° (off normal angle)

Table Dimensions:

72"L x 48"W x 33.5"H (1.83L x 1.19W x 0.85 H m.)

Sample sizes:

2"x 2" to 12"x 12" (5 x 5 to 30x30 cm)

(with appropriate sample holder and depending on frequency of measurement)


Spot width at the 3 dB points: 1 wavelength

Focal distance:

12" (30.5 cm.)

Depth of focus:

1 wavelengths

Cross-Polarization (minimum):

- 50 dB


Reflection Coefficient

± 0.4 dB ± 2°

Transmission Coefficient

± 0.2 dB ± 2°

Dielectric Constant (Teflon)

2 ± 3%

Loss Tangent (Teflon)

± 0.005

The MMS Free Space System is invaluable in the lab.

  • Test inhomogenous materials, curved materials, and materials which can't be machined precisely.
  • Very accurate measurements can be made quickly, ideal for research
  • Characterize electromagnetic materials:
    • Dielectrics
    • Absorbers
    • Metamaterials
    • Shielding materials
  • Measure electromagnetic properties:
    • Dielectric permittivity
    • Magnetic permeability
    • Radar absorption
    • Chirality parameter
    • Surface resistivity
    • Shielding effectiveness
  • A single sample, as small as 15x15 centimeters, can be characterized non-destructively from 5.85 GHz to 110 GHz.
  • Test at high and low temperatures (-40°C to 1500°C).
  • Take bistatic and oblique incidence measurements with arbitrary polarization.
  • Take high temperature measurements up to 1500°C and low temperature down to -40°C for electromagnetic characterization of materials as a function of temperature and frequency.