Frequency reconfigurable substrate integrated waveguide antenna

Nowadays, wireless communication is rapidly developed and tends to provide simultaneously multiple services while pursuing more compact size. This trend is driven by ever-increasing user demands, but it has been challenging the design of the commonly used static antennas. What is more, building RF filters into a chip is a challenge and wideband reconfigurable filters need large area and complexity. When a wideband CMOS transceiver on a chip became available, people started being attracted by the frequency reconfigurable antenna. If a single tunable antenna eliminates the need for multiple antennas and filters operating in various frequency bands, then the system can increase capacity, reduce a size and the number of components count, and quality of service [1]. In order to realize the reconfigurable antenna, a distributed tunable device in a compact package is essential. Until now, various technologies have been integrated as the tunable device, such as RF microelectromechanical systems (RF MEMS) [2, 3], ferroelectric thin films [4, 5], or varactor [6, 7]. In this work, the varactor is employed in order to change capacitance. It shows advantages in term of simplicity, low profile and easy to be mounted with other circuits.