This article proposes a reactive impedance surface (RIS)-loaded, inductively fed full-wave dipole (FWD) UHF RFID tag designed for metal-mounted and concrete-embedded prefabricated component traceability. The tag employs a small copper loop for inductive feeding, effectively matching both the high impedance of the FWD and the large capacitive component of the RFID integrated circuit across the UHF band. Metal tolerance is achieved by employing the RIS, which can compensate the parasitic capacitance and reduce strong interaction between the antenna and the metal plane. Experimental results demonstrate that the proposed single tag achieves a measured bandwidth (|S${_{{11}}} {\unicode {0x007C}}$$\leq -$10 dB) of 700 MHz (76.5%) and a maximal read distance of 22.62 m. When mounted on metal with the RIS, the bandwidth reduces to 632 MHz (69%), and the maximum reading distance decreases to 20.19 m. Additionally, when embedded in concrete, the antenna loading RIS and metal plane maintains a maximum read distance of 4.63 m, demonstrating robust performance in construction material environments.

A modified self-biased$\beta $-multiplier-based current reference (CR) circuit is proposed for ultralow-power Internet of Things (IoT) application and is realized without any resistors, bipolar junction transistors (BJTs), or operational amplifiers (OPAs). The proposed CR circuit directly generates the reference current from a modified$\beta $-multiplier, which is biased by a stacked diode-connected MOS transistor (SDMT)-based compensated through a complementary-to-absolute temperature (CTAT) voltage. The proposed CR is implemented in a standard 0.18-$\mu $m CMOS process with an active area of 0.0069 mm2and almost all transistors operate in the subthreshold region. Measurement results show that the temperature coefficient (TC) of the CR is 248 ppm/°C in a temperature range from$- 40~^{\circ }$C to$125~^{\circ }$C. The proposed CR exhibits a line sensitivity (LS) of 0.33%/V within the supply voltage range of 0.8–1.4 V. The output of the CR at room temperature ($25~^{\circ }$C) is 1.84 nA with a power consumption of 3.7 nW.