The paper presents two composite right/left-handed (CRLH) coplanar waveguide (CPW) zeroth-order resonant (ZOR) antennas which were designed, processed, and electrically characterized for applications in the millimetric wave frequency range. Two CRLH antennas were developed forf=27 GHz andf=38.5, GHz, respectively. The CRLH antenna onf=27 GHz shows a return loss ofRL<−18.78 dB atf=26.88 GHz. The −3 dB radiation characteristic beamwidth was approximately 37° and the gain wasGi=2.82 dBi. The CRLH antenna onf=38.5 GHz has a return loss ofRL<−38.5 dB atf=38.82 GHz and the −3 dB radiation characteristic beamwidth of approximately 17°. The gains wereGi=1.08 dBi atf=38 GHz andGi=1.2 dBi atf=38.6 GHz. The maximum measured gain wasGi=1.75 dBi atf=38.2 GHz. It is, upon the authors' knowledge, the first report of millimeter wave CRLH antennas on silicon substrate in CPW technique for use in mm-wave monolithic integrated circuit.