Provided are a method of interpolating an image by determining interpolation filter coefficients, and an apparatus for performing the same. The antenna configuration comprises a first antenna tuned to a first cell phone operating frequency and a second antenna tuned to a second cell phone operating frequency. The niobium suboxide powder is suitable for the production of: capacitors having an insulator layer of niobium pentoxide; capacitor anodes produced from the niobium suboxide powder; and corresponding capacitors.