SIW-Based Frequency-Tunable Self-Oscillating Active Integrated Antenna

Abstract

A frequency-tunable self-oscillating active integrated antenna (AIA) mainly composed of active circuit and 1×2 substrate integrated waveguide (SIW) antenna array is proposed in this paper. Manipulating bias voltage to the varactors loaded on SIW antenna could offer electronic control of oscillation frequency. The DC bias circuit of the varactors integrated in SIW cavity can provide compact structure. Due to the load effect of the high Q SIW cavity, the designed antenna exhibits low phase noise. According to the measured results, the effective isotropic radiated power (EIRP) ranges from 4.4 to 12.9 dBm which is superior to previous reports with the frequency tuning range of about 20 MHz. The phase noise is -92.7 dBc/Hz at 100 kHz offset. The measured results also show that the cross-polarization levels are almost 20 dB lower than the co-polarized one in the main beam direction at 5.698 GHz.