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—Energy conservation is essential in wireless sensor networks (WSNs) because of limited energy in nodes' batteries. Collaborative beamforming uses multiple transmitters to form antenna arrays; the electromagnetic waves from these antenna arrays can create constructive interferences at the receiver and increase the transmission distance. Each transmitter can(More)
— This paper presents a low power impulse generator design for ultra-wideband (UWB) impulse radio (IR) applications. Simple digital delay elements and a NAND gate are used to generate short duration pulses. A varactor controls the pulse width of the generated signal. The low-end of the spectrum of the generated pulse is attenuated using an integrated(More)
Intensity-modulated radiation therapy (IMRT) requires precise delivery of the prescribed dose of radiation to the target and surrounding tissue. Irradiation of moving body anatomy is possible only if stable, accurate, and reliable information about the moving body structures are provided in real time. This paper presents a magnetic position tracking system(More)
— A capacitively source degenerated buffer provides a negative impedance and can be used as the negative resistance cell in the voltage-controlled oscillator (VCO). This eliminates the need for a negative resistance cell within the VCO itself. Eliminating the negative resistance cell within the VCO allows us to reduce the overall power consumption for a(More)
— This letter analyzes the implementation issues related to coherent receivers for UWB impulse radio with a special emphasis on timing and jitter problems. We propose a new jitter tolerant receiver design that is easy to implement. Analytical BER analysis and simulations verify that the performance of the proposed receiver is comparable to that of a(More)
Reducing energy consumption is critical for wireless sensor networks. The dominant factor is the energy for data transmission. Collaborative beamforming can save transmission energy by improving the directivity of electromagnetic waves so that the signal at the receiver is stronger. Compared with a single transmitter, collaborative beamforming spreads the(More)
This paper presents a wide tuning range LC voltage controlled oscillator with a new differential negative resistance cell that uses capacitive source degeneration. Traditional differential negative resistance cell use two transistors where the drains are cross-connected to the corresponding gates and the sources are ac grounded. This structure has a fairly(More)