A first-harmonic push-push oscillator based active integrated dual-beam switchable array antenna

This paper proposes a new active integrated array antenna (AIAA) for dual-beam switchable functionality. The proposed AIAA comprises a first-harmonic push-push oscillator, four linearly polarized microstrip antennas, and a switchable feed network. The first-harmonic push-push oscillator eliminates the impact of load variation and usage of a filter to suppress the second- and higher-harmonic frequency signals. By using the switchable feed network, the main beam direction of the radiation pattern can be switched between two states, i.e. theta=+/- 10 circle$\mathbf {\theta = \pm }10\mathbf {<^>{\circ }}$. The performance of the proposed antenna is experimentally evaluated. The measured results show an effective isotropic radiated power (EIRP) of +27.5 dBm, DC-to-RF efficiency of 20.26%, and figure of merit (FOM) of -155.2 dBc Hz(-1) at the fundamental frequency of 5.9 GHz.