This paper presents a low voltage low power RF/analog front-end circuit for passive ultra high frequency (UHF) radio frequency identification (RFID) tag. Temperature compensation is achieved by a reference generator using sub-threshold techniques which requires lower supply voltage than conventional bandgap circuit. Some novel structures are developed to construct the building blocks, including...

For modern integrated circuits, capacitive coupling effects between interconnects can play an important role. Also resistive coupling effects via the substrate may have a significant influence on circuit behavior. This has already been recognized some time ago [1], and several methods to model these effects have been developed [2]. In this paper we will show how we can model coupling effects th...

A remarkably simple electronic circuit design based on the chaotic Lorenz system is described. The circuit consists of just two active nonlinear elements (high-speed analog multipliers) and a few passive linear elements. Experimental implementations of the circuit exhibit the classic butterfly attractor and the hysteretic transition from steady state to chaos observed in the Lorenz equations. T...

Direct printing nanoparticle-based conductive inks onto paper substrates has encountered difficulties e.g. the nanoparticles are prone to penetrate into the pores of the paper and become partially segmented, and the necessary low-temperature-sintering process is harmful to the dimension-stability of paper. Here we prototyped the paper-based circuit substrate in combination with printed thermopl...

This paper describes a new association of a high-Q pseudo 8-path switched-capacitor (S-C) bandpass filter and its command circuit made up by a ring VCO with ‘XOR’ gates. The proposed circuit presents the possibility of tuning over a radio-frequency (RF) broadband allowing to sweep different channels with a high quality factor. Designed with CMOS process (0.35μm, for instance), this circuit is i...

This paper reviews proposed realization concepts and achievements of wireless sensor nodes and focuses on new developments in the 24 GHz frequency range. The relatively high frequency offers the advantage of ultra miniaturization and therefore opens new application fields. On the other hand power consumption of the RF-front-end becomes still more challenging than at lower frequencies. It is sho...

A novel method is presented for electrically tuning the frequency of a compact radio-frequency identification (RFID) tag antenna. A tuning circuit, comprising a radio frequency (RF) switch and discrete passive components, was completely integrated into the antenna element, which is thus free of DC wires. The low-profile printed antennas were fabricated together with the layouts of the DC contro...

An eye-shaped segmented (ESS) antenna is presented for ultra-high frequency (UHF) near-field radio frequency identification (RFID) applications. The proposed antenna shows in-phase current even though the perimeter of the eye-shaped loop is comparable to the operating wavelength. The ESS antenna is fabricated on a FR4 printed circuit board (PCB) and embedded in a metal cavity with an overall si...

Less know-how is generally available with regard to the presented alternatives than for the traditionally brominated flameretarded printed circuit boards. The available information however shows that the substitution of brominated flame protection in printed circuit boards is both possible and sensible. This is supported by the available information about the substitutes and the by-products of ...