An MF-HF Miniaturized PMN-PT Electrostrictive Antenna for Superficial Earth Detection

The acoustically excited antennas based on the piezo-electric effect (PE) have been shown to reduce the size of the long wave communication system transmitter (Tx) to 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−4</sup> of the wavelength. However, their practical application is limited due to the narrow bandwidth and weak transmission energy associated with the piezoelectric resonance mechanism. In this letter, we present a PMN-PT relaxor ferroelectric ceramic doped with samarium (Sm), which significantly enhances the radiation performance of the PE Tx and exhibits electrostrictive capabilities ranging from medium-high frequency (MF-HF). Using a tiny Tx (4 mm in diameter and 3 mm in thickness), we achieved a radiation distance of over 30 m, with an average transmission gain of more than 13 dB higher than that of the traditional PE Tx. To verify the application, we have carried out the preliminary attempt of superficial earth detection. This design provides an effective method to promote the applications of piezoelectric Tx.