Kay Seemann

The Roots, Rules, and Rise of RFID

This article has offered a brief excerpt of the basic requirements and current development trends in (passive) RFID systems in different application areas. Even after reaching a sophisticated state of development, RFID technology is still dependent on sufficient acceptance at the market. Conventional bar code systems lack programmability, have low storage capability, and need a line-of-sight connection to the reader. If the fall in prices for low-cost tags continues, barcodes could be largely replaced in some years. In this case, additional features like positioning or sensing will become even more attractive for commercial and industrial application fields.

A Low-Power Low-Noise Single-Chip Receiver Front-End for Automotive Radar at 77 GHz in Silicon-Germanium Bipolar Technology

This paper presents a single chip receiver front-end, including low-noise amplifier and mixer, for application in automotive radar systems at 77 GHz. The circuit has been implemented in a SiGe HBT technology. The complete circuit occupies 1030 times 1130 mum2 including bond pads and dissipates 440 mW from a 5.5 V supply. The front-end shows a minimum measured single sideband noise figure (SSB NF) of 11.5 dB and a maximum conversion gain of 30 dB at 77 GHz. Linearity measurements show a 1 dB input compression point of -26 dBm and a third order intercept point of -21.6 dBm at 77 GHz.

A Low-Power Micromixer with High Linearity for Automotive Radar at 77 GHz in Silicon-Germanium Bipolar Technology

A direct-conversion micromixer realized in a modern SiGe:C bipolar technology for application in automotive radar systems at 77 GHz is presented. The mixer exhibits a minimum conversion gain of 15 dB and a maximum noise figure of 16.5 dB over a frequency range from 75 GHz to 85 GHz. The 1dB input related compression point is at -3dBm and the RF and LO matching is better than -20 dB and -10 dB, respectively. The total DC current consumption is 34 mA at 5.5 V

Ultra-Low-Power Rectification in Passive RFID Tags at UHF Frequencies

The commercial significance of ubiquitous chips, especially of radio frequency identification devices (RFID), and the advantages compared to other identification technologies, for e.g. the barcode, have been discussed in several papers. The passive RFID technology is mainly advanced by the increase of the operation distance and improvements regarding the operational reliability. In order to achieve these aims, the design of integrated circuits with an ultra-low power consumption and novel concepts for high-efficiency energy scavenging are an emerging task. This article deals with self-sustaining RFID devices, which use the RF power of the interrogator as an ambient power source. For high operation distances it is necessary to realize RF to DC conversion circuits, which can handle ultra-low-power levels. Thus, we present limitations and novel design approaches concerning rectification circuits at ultra-low power levels in the context of passive RFID systems at UHF frequencies. Index Terms – Ultra-low-power rectifiers, rectennas, RF-to-DC conversion, passive RFID, UHF RFID

Monolithic integration of microstrip line couplers for automotive radar applications at 77 GHz using a Si-HBT technology

A branch-line, rat-race and a reduced-size branch-line coupler have been realized in a modern SiGe:C bipolar technology for application in automotive radar systems at 77 GHz. The paper describes the design methodology of passive circuits on lossy Si-based substrate up to 110 GHz and gives measurement results of the manufactured circuits.

A 77 GHz SiGe Mixer Circuit with LO Active Frequency Multiplier for Automotive Radar

This paper presents a direct-conversion mixer for 77 GHz integrated with an active 4times LO frequency multiplier. The circuit was manufactured using a SiGe technology. Noise figure, conversion gain, linearity and s-parameter measurement results will be shown.