Low power ASK modulator based on direct injection‐locked current reuse VCO in 130‐nm CMOS technology for high data rate RFID applications

Abstract

A low power consumption Amplitude Shift Keying (ASK) modulator employing current reuse cross‐coupled (CRC) LC‐VCO topology and direct injection locking (IL) technique at 10.5‐GHz frequency is presented in this paper. The modulator consumes 864 μW with a DC supply of 1.2 V drawing an average current of 720 μA. The differential VCO is composed of a PMOS‐NMOS pair in stacked series cross‐coupled connection enabling current reuse which results in reduction of the average current drawn from the power source. For comparison, the ASK modulator is also realized with conventional cross‐coupled (CC) topology using NMOS pair. Both circuit approaches are carried out in GF 130‐nm CMOS technology and the post‐layout simulation results of 0.5 × 0.5 mm2 integrated circuits (ICs) show that the CRC topology consumes less power and half of the average current compared to CC topology. Owing to low power requirements, the CRC ASK modulator can be used in self‐powered active Radio Frequency Identification (RFID) tag transmitters for higher data rates.

A low‐power amplitude shift keying modulator based on adaptive body‐biased injection‐locked current‐reuse voltage controlled oscillator for high data rate radio frequency identification applications

“…Although the post-layout simulations suggest the modulator consumes power around 790 μW, the Monte Carlo analysis (as shown in Figure 13) gives a mean value of 710 μW with more samples' density in lower power values. So, we can conclude that in comparison to Yasir et al, 6 incorporating adaptive body-biasing results in 75-150 μW lesser power consumption while still maintaining a high data rate of 20 Mbps. The reduction in data rate compared to Yasir et al 6 is due to the lower supply voltage of 1.1 V resulting in lower voltage swings and symbols which are more prone to noise disturbances.…”

“…So, we can conclude that in comparison to Yasir et al, 6 incorporating adaptive body-biasing results in 75-150 μW lesser power consumption while still maintaining a high data rate of 20 Mbps. The reduction in data rate compared to Yasir et al 6 is due to the lower supply voltage of 1.1 V resulting in lower voltage swings and symbols which are more prone to noise disturbances.…”

“…The difference between the proposed modulator and the work in Yasir et al 6 is the inclusion of adaptive body‐biasing mechanism. NMOS is replaced by the deep n‐well NMOS in the cross‐coupled pair; addition of PMOS‐NMOS pair for generating body‐biasing signal and inclusion of a capacitor at center‐tap point of the inductor to improve amplitude imbalance are the key changes made.…”

“…The circuit comprised of conventional cross‐coupled LC‐voltage‐controlled oscillator (VCO) injection locked by incoming signal from the reader and acted as amplitude‐shift keying (ASK) modulator/demodulator for uplink/downlink communication. We 6 presented an ASK transmitter approach based on current‐reuse VCO in which both factors, i.e., current‐reuse architecture and injection locking, enable a low‐power, low‐phase noise VCO and ASK modulator, suitable for high data rate tag to reader communication. A comparison was also performed between conventional cross‐coupled and current‐reuse VCO approaches for realizing ASK modulators, and it was concluded that current‐reuse architecture consumes less power and half of the average current.…”

Development of intelligent management system for health combat readiness materials based on RFID technology

“…With the rapid development of China's economy, domestic market competition is becoming increasingly fierce, and all industries are striving to improve their competitiveness. At present, the degree of intelligence in the health field is constantly improving [1][2]. However, due to the lack of unified and standardized management, effective monitoring and control technology and other reasons, the current health management system has many problems that need to be solved and improved, and puts forward new ideas, innovative research directions and prospects for the future to cope with the pressure caused by the sharp increase in demand for medical resources, as well as the diversification of people's requirements, making security risks the most important and must pay attention to [3][4].…”