Measured characteristics of multi-gap loop and asymptotic conical dipole electromagnetic field sensors

The frequency responses of the MGL-2D(A), MGL-6A(A) and ACD-4A(R) free-space sensors have been measured and analyzed. The measurements were made over the frequency range 118 to 4400 MHz whose upper limit far exceeds the 3-dB roll-off frequencies for the sensors. All three sensors were evaluated in terms of the linearity of the frequency response, the angular behavior vis-a-vis a dipole pattern, and the rotational symmetry (MGL sensors only). Whereas the linearity persists only slightly beyond the roll-off frequencies, the dipole and symmetry properties extend to frequencies two or three times greater. In addition, some preliminary data for the MGL-5B(R) and MGL-7A(R) ground plane sensors are presented.