Methods and systems are disclosed for scalable antenna arrays that may be built up using pluggable tiles that have low distortion, flat band high gain, and structured to channelize the signals into narrow bands that may be 40 MHz or even smaller bandwidth apart. Antenna array tiles may employ traveling wave tube (TWT) components and wafer scale arrays. H-topology, equal length, feed networks connect the signals to antenna elements. The fractal-like, recursively repeating at different size scales, structure for the H-tree feed networks, implemented using pluggable tiles, facilitates the scalability of the high gain waveguide antenna array. System integration across the 75-115 GHz spectral band implements scalable aperture architecture with emphasis on addressing considerations of the TX power requirement, feed network, channelizing signals at different frequency bands using specially designed diplexers and combiners, cooling, component placement, and isolation.