Self-oscillating Active Antenna with Voltage Tuning for 5 GHz WLAN

In this paper, a self-oscillating voltage tuning antenna using varactor diode is presented. While Self-Oscillating Active Antenna (SOAA) can be realized in different ways, in this work we made direct integration of the transistor and the C-shaped ring radiator (feedback circuit). Specifically, we study two parts of the configuration, the first for the design of a self-oscillating antenna that oscillates exactly at 5.432 GHz. The second goal is to design the active SOA to oscillate in the interval [5.16–5.8] GHz; this is the objectif of writing this communication. The oscillator is designed on a Rogers R04003C substrate. The adopted substrate height is ℎ = 0.508 mm, the dielectric constant \(\varepsilon_{r}\)   = 3.38, and the loss tangent is 0.0027. A harmonic balance simulation is used to get the out-put voltage spectrum. The obtained results are based on the simulations carried out with Advanced Design System (ADS) tool. The resonant frequency is 5.432 GHz, with an output power of 8.23 dBm. Finally, we managed to obtain a SOA whose resonance frequency sweeps at the proposed interval (5 GHz WIFI WLAN band).