24 together comprise the secondary mirror conductor conversely the antenna array may be fabricated as part of the primary mirror conductor secondary mirror conductor 22 24 forms a flexible membrane fabricated such that it is under tensile stress and thus parallel to the substrate in an undriven state because layers 22 and 24 are parallel radiation which enters any of the cavities from above or below the array can undergo multiple reflections within the cavity resulting in optical interference depending on the dimensions of the antenna array the interference will determine its reflective and or transmissive characteristics changing one of the dimensions in this case the cavity height i e the spacing between the inner walls of layers 18 22 will alter the optical characteristics the change in height is achieved by applying a voltage across the two layers of the cavity which due to electrostatic forces causes layer 22 to collapse cavity 12 is shown collapsed 7 volts applied while cavity 14 is shown uncollapsed 0 volts applied in fabricating the array 10 it is desirable that insulating supports 20 are well defined in regions where contact is made between insulating supports 20 and layers 18 22 the present invention is especially useful in manufacturing such a support fig2 through 10 show various stages in the manufacture of a mems device having supports such as the supports 20 referring to fig2 of the drawings reference numeral 100 indicates a substrate 100 the substrate 100 may be of many different materials each being transparent to ultraviolet light examples of these materials include plastic mylar or quartz the material must be able to support an optically smooth though not necessarily flat finish a preferred material would likely be glass.