Özbay, EkmelTuttle, G.McCalmont, J. S.Sigalas, M.Biswas, R.Soukoulis, C. M.Ho, K. M.2016-02-082016-02-0819950003-6951http://hdl.handle.net/11693/25868We have used laser-micromachined alumina substrates to build a three-dimensional photonic band-gap crystal. The rod-based structure has a three-dimensional full photonic band gap between 90 and 100 GHz. The high resistivity of alumina results in a typical attenuation rate of 15 dB per unit cell within the band gap. By removing material, we have built defects which can be used as millimeter-wave cavity structures. The resulting quality ~Q! factors of the millimeter-wave cavity structures were as high as 1000 with a peak transmission of 10 dB below the incident signal. © 1995 American Institute of Physics.EnglishAluminaAttenuationElectric conductivityElectromagnetic wave transmissionEnergy gapMillimeter wavesNatural frequenciesNumerical methodsQ factor measurementThree dimensionalBand gap cavity structuresLaser machined waferPhotonic band gapTransfer matrix methodCrystal defectsArticle10.1063/1.114756