Ahmadreza Rofougaran

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A 900-MHz direct-conversion receiver to detect a frequency-hopped carrier with frequency shift keying (FSK) modulation at 160 kb/s is integrated on the same chip as the transmitter. The receiver combines a low-noise amplifier with downconversion mixers and low-pass channel-select filters in quadrature channels. A digital correlating detector makes the data(More)
This paper presents integrated blocker filtering RF front-ends (BF-RF). In wireless cellular systems the blockers are from either self transmitters, such as WCDMA or form the other users' transmitters such as GSM. The proposed blocker filtering deploys the concept of blocker injection through feedforward or feedback paths to create arbitrary narrowband(More)
This paper presents a guideline to design and optimize a power harvester circuit for an RF identification transponder. A power harvester has been designed and fabricated in a CMOS 0.18- process that operates at the UHF band of 920 MHz. The circuit employs an impedance transformation circuit to boost the input RF signal that leads to the improvement of the(More)
This paper presents a novel active blocker rejecting RF (ABR-RF) front end for RF identification (RFID) applications. The proposed ABR-RF injects the blocker replica within the low-noise amplifier of the RFID receiver chain, through a feed-forward path to actively create an arbitrary narrowband notch filtering for the in-band blockers, while not affecting(More)
A two-point modulation technique is presented that improves the performance of nonlinear power amplifiers (PAs) in polar transmitters. In this scheme, the output amplitude modulation is performed by controlling the current of the PA. The current control technique enables the PA to provide wideband amplitude modulation, as well as high power control dynamic(More)
A novel switching power amplifier based on the concept of digital to analog converter (DAC) is presented for polar transmitter architecture. The novel idea in this amplifier is to generate a current proportional to the amplitude modulation signal and the power control bits. The current is then up-converted to the frequency of interest using switching(More)
This paper presents an RF identification (RFID) system with a fully integrated transponder. To enable the on-chip integration of the tag's antenna, it is suggested to employ near-field coupling at high-frequency ranges, i.e., the UHF band. The RFID system including the reader and key blocks of the transponder is designed and fabricated in a standard CMOS(More)