US 5,477,229 A · Active antenna near field calibration method

Abstract

In a method of calibrating an active antenna the active elements of a transfer function matrix are measured using a near field probe for each radiating source of the antenna. The probe is placed in front of each source in succession and each source is excited in turn with the opposite phase and with all the other sources of the array excited normally. In the case of linear superposition of radiated fields, the measurements obtained by this method yield the elements of the transfer function matrix directly. This allows for phase and amplitude errors due to the components of the active antenna and for the effects of coupling between adjacent sources which modify the theoretical characteristics of the antenna. In the non-linear case the measurements are repeated and the matrix is obtained by iteration based on a comparison of the theoretical values used to control the antenna and the measured fields actually obtained. Measurements carried out on individual active modules prior to assembly of the antenna can be used in one variant of the method.

Claims17

Dependent claims

A method of calibrating an active antenna having N radiating sources respectively associated with N signal channels each having an active module including a phase shifter, said method comprising the steps of:

placing only a single probe in front of each radiating source in succession to measure the near field in front of said source for an antenna configuration required to obtain a required radiation pattern;
and, during said measuring of said near field in front of said source, causing the phase shifter of each channel in turn to shift the phase of radiation by said channel 180.degree. relative to its nominal value while maintaining each of the other N-1 sources operating at their respective nominal value for said configuration in order to obtain the required radiation pattern, whereby phase control values are determined and applied to each phase shifter to effect the calibrating of the antenna.

A method of calibrating an active antenna having N radiating sources respectively associated with N signal channels each having an active module including phase shift means and gain control means, said method comprising the steps of:

placing only a single probe in front of each radiating source in succession and measuring the near field in front of said source for an antenna configuration required to obtain a required radiation pattern;
during said measuring of said near field in front of said source, causing the phase shift means of each channel in turn to shift the phase of radiation by said channel 180.degree. relative to its nominal value while maintaining each of the other N-1 sources operating at their respective nominal value for said configuration in order to obtain the required radiation pattern;
and determining gain and phase control values and applying them to each phase shift means and gain control means to effect the calibrating of the antenna.

Dependencies are inferred from the claim text.

Active antenna near field calibration method

Life of this patent

Active antenna near field calibration method

Life of this patent

Abstract

Claims17