The book presents the work done on the Design and fabrication of a dual mode helix antenna for satellite and wide band terrestrial communication. The antenna is used on satellite platform and also on hand held devices which require communicating or receiving data from satellite. For future communication needs, there is requirement of devices which can provide seamless services, integrating both terrestrial and space communication. Bifilar helix antenna is one candidate antenna that can be integrated into Quadrifilar helix antenna to provide both space and land communication. Since numbers of services are offered by terrestrial links over a large bandwidth, handheld devices require wideband antenna with Omni-directional radiation pattern for land communications. Numerical Electromagnetic Code (NEC) software is used to carry out simulations for the design and to see how the design is comparable to the specifications. In this book, a Bifilar Helix antenna is presented with different configurations of a Quadrifilar Helix structure along with its stepwise design, simulation and hardware prototype to achieve a helix antenna for dual mode communication.