Christian Klapf

A Triple-Band Passive RFID Tag

This paper presents a broadband analog interface in 0.12 mum CMOS without a Schottky Diode process-option, which powers the chip from 1MHz to 2.45GHz and communicates with EPC UHF and HF. To profit from the application benifit of both13.5613MHz HF RFID systems used in identification and 860 to 960MHz UHF RFID systems used in supply chain applications, two frequency selective tags or one broadband chip with one antenna are necessary.

Analyses and design of low power clock generators for RFID TAGs

This paper introduces a new clock generation concept with a PLL for HF RFID systems. Low power consumption of 1.9 muW and a good decoupling against power supply and bias variations are necessary to reach HF RFID timing and energy performance requirements. All presented oscillator topologies can be used in UHF EPCglobal class1 gen2 RFID systems as local oscillator with a minimum frequency of 1.92 MHz. For all oscillators the PSR, power consumption and temperature drift are simulated and partly measured. In the CTS1 project a new VCO and local oscillator concept was developed and manufactured on an Infineon 120 nm CMOS test-chip. The PLL is simulated with the same process technology.

Improvements in Operational Distance in passive HF RFID Transponder Systems

This paper introduces new transponder-design concepts which aim to enhance the working range in passive HF RFID systems. Sideband theory, system architecture, chip design, verification and interdependencies will be discussed. Test- chip measurements show a decrease of 40% in field strength requirements for operation. The working range enhancement compared to products currently available on the market is at least 20% depending on the reader unit setup.

Inverse load modulation circuit concept for passive RFID transponder

SummaryThis paper addresses a new shunt regulation and modulation control concept to reduce parasitic self heating effects and improve communication distances in passive HF RFID systems. A new circuit design for low antenna voltages in RFID tags is presented. For tag to reader communication the principle of inverse load modulation is applied.ZusammenfassungDer Artikel beschreibt ein neues Längsregler- und Modulationskonzept zur Verbesserung der Eigenerwärmungsproblematik und Erhöhung der Systemreichweite für passiv gekoppelte HF RFID-Systeme. Weiters wird ein neues Schaltungskonzept für kleine Antennenspannungen präsentiert und inverse Lastmodulation für die Rückantwort des Tags eingeführt.