E-Plane Omnidirectional RFI Monitoring System
             Figure shows placement of antennas & Effective radiation pattern of all 4 antennas. For a particular incoming signal at a certain frequency and certain power, the output powers from the 4 antennas will be unique depending on their radiation patterns. If the signal lies in or near the E-plane of the antenna system, two of the antennas delivering the first and second largest power values determines the quadrant in where the signal lies.