antennas to which a test signal is applied and for which excitation coefficients are applied such that the test signal approximates a single plane wave or a preselected superposition of plane waves in the near field of the antennas the test equipment antennas in the chamber may be as close as one wavelength from the boundary of a test zone in which the dut is disposed hence the test zone can be in the near field of the test equipment antennas and the test zone can be less than a wavelength from the chamber walls consequently it is possible to perform tests in a small anechoic chamber that previously required a large anechoic chamber e g advanced spatial channel model tests and antenna pattern measurements application_number US 201514731916 A description creating a single plane wave in the near field of antennas and scatterers fig1 illustrates a wireless test system including an anechoic chamber 100 and channel emulator 102 the anechoic chamber includes walls which are absorbing but not perfectly absorbing so a field produced by n antennas 104 1 104 2 104 3 104 n disposed in the chamber is scattered by the walls also a field produced by one antenna will scatter off all the other antennas the channel emulator includes computer programs stored on non transitory computer readable media and processing hardware for creating modifying amplifying and otherwise generating signals that are provided to the antennas for transmission in one aspect each of the antennas is fed by a time harmonic signal with complex amplitude a n with n 1 2 n in order to present.