To use an antenna that is not listed on your wireless modules datasheet, it must be of the same topology (e.g. dipole, PIFA, etc.), equal or lesser gain, and have the same in-band and out of band characteristics.
Note: Japan (MIC) lists applicable antennas on its certificates. If your antenna is not on the approved list, regardless of whether it is comparative, it must be added to the certificate before it can be used in Japan.