31. Metro uses DOCSIS 2.0 over microwave frequencies . 32. These competitions are called " cumulative " contests, and are generally limited to the microwave frequency bands. 33. Ohmic losses of waveguides at microwave frequencies are therefore only dependent on the surface coating of the material. 34. This demanded higher resolution than the original VHF design, although not as high as the MAR's microwave frequencies . 35. However, it is used in theoretical work in network analysis and has some niche applications at microwave frequencies . 36. US West is also looking at " wireless cable " _ transmitting cable television programming via microwave frequencies . 37. VII, AI moved to microwave frequencies using the cavity magnetron, greatly improving performance while reducing size and weight. 38. Work also began on a new microwave frequency radar to replace Chain Home, initially known as Green Garlic. 39. Where \ tilde { n } denotes the " complex " formula which is valid up to microwave frequencies . 40. The brothers and Hansen ultimately created the klystron, the first tube that could generate electromagnetic waves at microwave frequencies .