Ibrahim Tekin

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In this paper, an UHF band 2X2 microstrip phased antenna array is designed for extending the range of an RFID reader system. The phased antenna array operates at the frequency of 867 MHz, as specified in Gen2 protocol European standards. The phased antenna array has four microstrip patch antennas, three Wilkinson power dividers and a transmission line phase(More)
This paper presents a low-cost Ultra Wideband (UWB) pulse generator that can vary the pulse duration digitally by using a Step Recovery Diode (SRD), microstrip transmission lines and PIN diodes. First, a sharp edge is generated by using a SRD circuitry. Then a pulse is formed from the sharp edge through the use of transmission lines and the PIN diodes.(More)
This paper presents a comprehensive comparison of three state-of-the-art heterojunction bipolar transistors (HBTs); the AlGaAs/GaAs HBT, the Si/SiGe HBT and the InGaAs/InP HBT. Our aim in this paper is to find the potentials and limitations of these devices and analyze them under common Figure of Merit (FOM) definitions as well as to make a meaningful(More)
Due to the FCC requirement that operators of mobile communications networks be able to accurately locate mobile callers requesting emergency assistance via 911 by the year 2001, there has been substantial research and development activities dedicated to examining cellular positioning options. Fueled by this new requirement, the network operators are also(More)
In this paper, a reconfigurable microstrip patch antenna with RF pin diode switches is implemented for dual band of 2.4 GHz and 5.6 GHz Software Defined Radio (SDR) applications. For the dual band SDR system, the use of a single antenna with a wide bandwidth to cover both of the bands can be limiting for low power level signal applications due to wideband(More)
A novel on-chip RF choke at 5 GHz is designed and measured for a class A operating Wireless LAN RF power amplifier (PA). The coplanar waveguide (CPW) based on-chip RF choke is implemented as an alternative component to inductors provided by the 0.35 μm SiGe BiCMOS technology. The CPW RF choke is designed at 5 GHz, and has a length of 1600 um and loaded with(More)
This paper presents a comprehensive review of diamond electronics from the RF perspective. Our aim was to find and present the potential, limitations and current status of diamond semiconductor devices as well as to investigate its suitability for RF device applications. While doing this, we briefly analysed the physics and chemistry of CVD diamond process(More)
In this paper, a 4.2–5.4 GHz, Gm LC voltage controlled oscillator (VCO) for IEEE 802.11a standard is presented. The circuit is designed with AMS 0.35 lm SiGe BiCMOS process that includes high-speed SiGe Heterojunction Bipolar Transistors (HBTs). According to post-layout simulation results, phase noise is 110.7 dBc/Hz at 1 MHz offset from 5.4 GHz carrier(More)