Distributed Amplifier with CRLH-Transmission Line Leaky Wave Antenna

We propose a distributed amplifier integrated with a CRLH leaky wave antenna. This active antenna uses the interdigital capacitor-based CRLH transmission line, microstrip line and FETs. To coordinate the phase between the guided slow-wave in the microstrip section and fast-wave in the CRLH radiator, the length of the unit cell of the microstrip section is shortened and FETs are connected with a constant phase coupling line. The signal travels to each unit-cell through FETs and radiate from the CRLH antenna. This antenna radiates an amplified forward wave in the right hand region and an amplified backward wave in the left hand region. A 5 unit-cell prototype demonstrates the proposed active leaky wave antenna. The measured and simulated forward and reverse gains exhibit good agreement, and beam scanning can be observed.