The purpose of this test is to determine antenna gain, directionality, and impedance in the frequency bands listed in Appendix B (Tables B1 and B2). Gain refers to the ratio of the magnitude of an antenna radiation pattern compared to that of a reference antenna. Directionality refers to the uniformity of an antenna radiation pattern. This document specifies requirements and test procedures for verification of high frequency (≥ 450 MHz) antenna system performance for all General Motors vehicles marketed and sold around the world. This document applies to passenger vehicles and trucks. In this document, an active antenna is defined as an antenna system where any part of it requires electrical power from the vehicle to function as specified. A passive antenna is defined as an antenna that requires no power; whose gain is derived solely from the actual antenna structure.
Applicability.
This test procedure shall apply to all passive and active antennas. This procedure is applicable to the development and validation of antenna systems for new vehicle programs as well as design changes for current vehicles.