Multi-band active integrated antenna using Clapp oscillator circuit

In this study, we present a multi-band CPW-fed active integrated antenna with using a Clapp oscillator circuit. The active antenna consists of a feedback network, which is composed of a low noise hetero junction field effect transistor (HJFET), and a coplanar waveguide (CPW)-fed antenna tuned with an LC circuit. The active integrated antenna has triple resonant frequency bands at 0.80 GHz, 2.40 GHz and 3.15 GHz with the bandwidth of 200 MHz, 120 MHz, and 150 MHz, respectively. The measured power added efficiencies (PAE) and antenna gains are 43.0 %/−1.47 dBi at 0.80 GHz, 54.5 %/−0.32 dBi at 2.40 GHz, and 65.8 %/−2.02 dBi at 3.15 GHz, respectively.