Isotropic Omnifield Antenna® OFA-SE 30MHz-3GHz

Omni ant OFA-S PIC6

Omnifield Antenna® Model: OFA-SE


A unique broadband active E- field isotropic (spherically isotropic) antenna for RF spectrum monitoring. Connects to any spectrum analyzer, and has frequency response practically independent of antenna orientation or electric field direction. Offers high sensitivity and broad dynamic range for the variety of RF regulatory, safety, EMC, wireless and telecommunications applications.  This antenna is very similar to OFA-S antenna but has about 10 times (20 dB) higher sensitivity.   For strong RF fields measurements (up to 300 V/m) use the OFA-S antenna.

OFA on Tripod with SA Front  

Omnifield Antenna® consists of three parts: antenna head, handle and power unit. Antenna head and handle comprise a single module while power unit is detachable from the handle to allow convenient storage in the supplied rugged plastic case. For normal operation handle must be connected to the power unit to provide power to the antenna head.  Antenna head has 3 antennas positioned normal to each other.  Signals from each antenna are combined and amplified to allow utput signal of Omnifield Antenna® to be proportional to the absolute value of the field regardless of the field direction.  Power unit contains the rechargeable battery and connectors for the antenna and output cable. Ferrite beads, located on this cable, decouple the antenna from spectrum  analyzer and reduce the effects of this analyzer on measured field. This cable also allows operator to have freedom to place the antenna in right position either on non-metal table tripod (supplied with every system) or onto optional 5 feet adjustable tripod.




Isotopic ant pic1    

Omnifield Antenna® OFA-S•E

  • Portable isotropic 3-axis EM field antenna with broadband response.
  • • Wide field dynamic range: 1 mV/m – 30 V/m @30-3000 MHz.
  • • Noise Level ~0.3 mV/m @ 1 GHz @ BW 1 KHz.
  • • Broad frequency range: 30 MHz- 3 GHz.
  • • Probe directivity: Omnidirectional.
  • • Calibration accuracy: +/- 1 dB.
  • • Linearity deviation Defined by SA.
  • Typically, better than +/- 0.5 dB.
  • • Rotational isotropicity (typ.): +/- (1.5-3) dB.
  • Recommended SA BW: 30 KHz (min BW 1 KHz )
  • Special 1.5 m (5 ft.) low loss high flexibility cable (supplied with unit). Cable has multiple ferrite beads to minimize cable effects on the measured field

Omni ant OFA-S PIC3

  • • Design: rugged portable enclosure. Antenna head is mounted on nonmetal handle with output connector detachable from the power unit.
  • Probe clip and nonmetal portable tripod are provided. Operating temperature: 0 C° to 50° C, RH 10%-90%, noncondensing. Temperature error: <0.08 dB/°C.
  • • Dimensions: Antenna: (LxD) 225×70 mm,9.0×2.75 inch.
  • Power unit: (LxWxD) 95x58x32 mm, 3.75×2.25×1.25 inch.
  • • Weight: Antenna: 0.66 lb. (300 g),
  • Power Unit: 0.44 lb. (200 g).
  • • Battery operation time: 8 hr. NiMHd rechargeable battery.
  • Charge, fast charge and low battery indicator.
  • • Calibration: Every antenna, cable and power module calibrated together with 5 feet cable for AF. NIST or UK NPL traceable
  • Calibration Certificate is supplied with each unit.
  • • Accessories: Omnifield Antenna® comes in foam padded hard carrying case and includes the OFA-S antenna, PU-5S power module, cable, tripod, plastic clip and product documentation.

Note: This Specification may be changed without notice due to continuous improvement of the design and manufacturing process.



Calibration Details: Isotropic Antennas Calibration


– Keep unit calibrated. We recommend calibration once a year in our UK NPL traceable EMC Test Lab.

1) Antenna Factors (AF) at 16 specified frequencies in the frequency range

30 MHz-3000 MHz (@ 1 V/m)

2) Antenna Rotational isotropicity at every frequency.

3) For Selective Spectrum Analyzer we provide a memory card with AF data.

– To convert the electric field strength E (V/m) into power density S (uW/cm2) use formula: S=E2/3.77. To calculate the value of the magnetic field H (far field region) use the relationship: E/H=377 Ohm.





EMC Test Design, LLC®,P.O. Box 600532, Newton, MA 02460, USA.

*protected email*,, 508-292-1833




RF Transmitter Certification (Frequency Selective)

Field strength measurements around power transmitters clustered in one location.



In the field.



Isotropic antenna.


Traceable Calibration (UK NPL).



Isotropic Antenna OFA-S/SE (30 MHz-3 GHz).

Selective Field Analyzer SFA-S.



Portable Spectrum Analyzer (for OFA-S/SE).

Laptop PC (for SFA-S/SE).


                                                                                       Enviromental and RF “Smog” Monitoring

Monitoring of the environmental RF spectrum, selective or broadband



In the field, industrial or living spaces, portable or permanently installed, networked.



Isotropic antenna.

Traceable calibration (UK NPL).


Isotropic Antenna OFA-S/SE (30 MHz-3 GHz).

Selective Field Analyzer SFA-S/SE.

Portable Spectrum Analyzer (for OFA-S/SE).

Laptop PC (for SFA-S/SE), unless networked.