Tracker tags, smart tags, locator tags, and the like are provided. A portable tracker device, according to one implementation, includes a housing having a front cover and a back cover. The portable tracker device also includes Radio Frequency (RF) circuitry configured to operate within at least one of a Bluetooth (BT) frequency range and an Ultra-Wideband (UWB) frequency range. Also, the portable tracker device includes a piezoelectric device having a first conductive plate and a second conductive plate. The RF circuitry utilizes at least one of the front cover, the back cover, the first conductive plate, and the second conductive plate as one or more antennas.