2,822 research outputs found
A Fully Integrated 24-GHz Eight-Element Phased-Array Receiver in Silicon
This paper reports the first fully integrated 24-GHz eight-element phased-array receiver in a SiGe BiCMOS technology. The receiver utilizes a heterodyne topology and the signal combining is performed at an IF of 4.8 GHz. The phase-shifting with 4 bits of resolution is realized at the LO port of the first down-conversion mixer. A ring LC voltage-controlled oscillator (VCO) generates 16 different phases of the LO. An integrated 19.2-GHz frequency synthesizer locks the VCO frequency to a 75-MHz external reference. Each signal path achieves a gain of 43 dB, a noise figure of 7.4 dB, and an IIP3 of -11 dBm. The eight-path array achieves an array gain of 61 dB and a peak-to-null ratio of 20 dB and improves the signal-to-noise ratio at the output by 9 dB
The Impact of Information and Communication Technology (ICT) on Teaching English to College Students
Teaching in general and language teaching in particular has enormously changed through time. Language teaching, throughout the twentieth century, experienced massive changes and innovations to become more dynamic, active, and interactive. Language teaching in the twentieth century has witnessed diverse theories and trends which shaped language teaching based on needs, context, practicality, and availability of resources. Meanwhile, there has been the addition of information and communication technology (ICT) to the theories and methodologies mentioned. The Internet, in particular, is becoming an increasingly vital tool in our information society. In this research, which is a quasi-experimental study, we studied the effects of ICT on a sample of 55 EFL college students. The findings show that ICT enhances language learning experience and can act as an effective tool both for teaching and learning. The author hopes the current study makes its way into the education system both in high schools and universities and can persuade the teachers to integrate ICT and teaching
A 24-GHz SiGe Phased-Array Receiver—LO Phase-Shifting Approach
A local-oscillator phase-shifting approach is introduced to implement a fully integrated 24-GHz phased-array receiver using an SiGe technology. Sixteen phases of the local oscillator are generated in one oscillator core, resulting in a raw beam-forming accuracy of 4 bits. These phases are distributed to all eight receiving paths of the array by a symmetric network. The appropriate phase for each path is selected using high-frequency analog multiplexers. The raw beam-steering resolution of the array is better than 10 [degrees] for a forward-looking angle, while the array spatial selectivity, without any amplitude correction, is better than 20 dB. The overall gain of the array is 61 dB, while the array improves the input signal-to-noise ratio by 9 dB
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