Patent ID: 7098677

Claim:
A method of measuring intensity of an electromagnetic field surrounding a device-under-test, comprising the steps of: (a) disposing an unshielded conducting loop of an antenna at a first position within a region where electric coupling and magnetic coupling take place between said antenna and said device-under-test in at least a portion of a frequency band, the antenna being disposed so it does not include a shield that affects an electromagnetic field coupled from the device to the antenna; (b) measuring the values of a plurality of output currents flowing in the loop of said antenna in different directions while the electric and magnetic coupling are occurring and the loop is at the first position, the currents flowing in said portion of the frequency band; (c) calculating (i) a value of an electric coupling current generated in the loop of said antenna in response to the electric coupling between said device-under-test and said antenna while the loop is at the first position, and (ii) a value of a magnetic coupling current generated in the loop of said antenna in response to magnetic coupling between said device-under-test and the loop of said antenna while the loop is at the first position, the calculation step being based on the measured values and said directions of said output currents; (d) calculating the intensity of the electric field and the intensity of the magnetic field based on said values of said calculated electric and magnetic coupling currents; (e) moving the loop of said antenna to a second position within the region, and then again performing steps (b), (c) and (d) so that there are first and second sequential measuring steps (b) in response to the loop being at the first and second positions, and first and second calculating steps (c) and (d) that are respectively performed in response to the first and second measuring steps (b); and (f) responding to the first and second calculations resulting from step (d) to obtain a measure of the spatial distribution of intensity of the electromagnetic field surrounding the device under test.