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Characterization of a Concurrent Dualband NIVSD Sensor
Published in Brijesh Iyer, Nagendra Prasad Pathak, Multiband Non-Invasive Microwave Sensor, 2018
Brijesh Iyer, Nagendra Prasad Pathak
It is evidenced from Figure 5.10 that after FFT of the desired band signals, multiple peaks are found to be present around 20 Hz and 70 Hz. These peaks are due to noise and environmental interference. Hence, it becomes difficult to identify the exact respiration and heartbeat signals using a particular single band and may lead to the incorrect detection of human life. This ambiguity is outweighed by applying correlation between the two signals. The cross-correlation plot clearly predicts the respiration and heartbeat signals. The signals at 22 Hz and 72 Hz are the required respiration and heartbeat signals. It is also apparent that, though the measurements are carried out at different bands, the detection sensitivity is not altered. This is due to the concurrent multiband operation. In addition, the correlated signal is more sensitive in comparison with the individual bands and provides better accuracy. When the distance between the human subject and the transceiver is increased, the detection sensitivity decreases. This is due to reduced received power strength. In the current measurement setup, the PA and intermediate frequency amplifier (IFA) were not used. The detection sensitivity can be easily improved by employing a PA at the transmitter end and an IFA at the receiver end. With increased detection sensitivity, it is possible to detect life even under metal structures or other impediments.
Introduction
Published in Habibur Rahman, Fundamental Principles of Radar, 2019
Receiver: The receiver is basically a superheterodyne type consisting of low-noise radio frequency amplifier, a mixer, an intermediate frequency (IF) amplifier, a video amplifier, and a display unit. The front-end RF amplifier is usually a parametric amplifier or a low-noise transistor. The mixer and local oscillator (LO) convert the RF signal into an IF signal having a center frequency 30 or 60 MHz and a bandwidth of the order of 1 MHz. The intermediate frequency amplifier is primarily designed as a matched filter6 and the pulse modulation is extracted by the second detector. The demodulated signal is then amplified by the video amplifier to a level suitable for displaying in an indicator, usually a cathode-ray tube (CRT).
High Volume Microwave Test
Published in Mike Golio, Commercial Wireless Circuits and Components Handbook, 2018
Jean-Pierre Lanteri, Christopher Jones, John R. Mahon
We will focus in this section on the different functions in the RF front end of a wireless phone to illustrate the typical products tested, their function, specification, and performance. The generic building blocks of a RF front end (Fig. 20.1) are switches (for antenna, Transmit/Receive (T/R), or band selection), input Low Noise Amplifiers (LNA), output Power Amplifiers (PA), up- and downconverters (typically comprising a mixer), Local Oscillator Amplifier (LOA), and Intermediate Frequency Amplifier (IFA). In most cases, these products are single band, either cellular or PCS, although new dual band components are appearing, requiring two similar tests in sequence, one for each band.
Energy efficiency analysis of linear receivers for large antenna system in fading channels
Published in International Journal of Electronics Letters, 2018
Arzoo Khetarpal, Rajesh Khanna
where M is the number of antennas located at the transmitter and P is number of antennas located at the BS. PDAC is the power utilisation value of digital to analogue converter (DAC), PMIXR is the power utilisation value of mixer, PFILTR is the power utilisation value of filters that are active at the transmitter end and PFILRR is the power utilisation value of filters that are active at the receiver end. PLNA and PIFA are the power utilisation values of low noise amplifier (LNA) and intermediate frequency amplifier (IFA). PADC and PSYN are the power utilisation values of analogue to digital converters (ADC) and frequency synthesiser, respectively. By incorporating large-scale fading the equations becomes intractable to plot so we are neglected the effect of large-scale fading. The per cell EE of MRC receiver neglecting the effect of large scale fading is given by
Lifetime maximisation with guaranteed minimum end-to-end energy consumption scheme for virtual multiple-input-multiple-output in wireless sensor networks
Published in Australian Journal of Electrical and Electronics Engineering, 2019
where is the power consumed by the Analog to Digital converter (ADC), is the power consumed by the receiver side filter, is the Intermediate Frequency Amplifier (IFA) power consumption, is the power consumed by the Low Noise Amplifier (LNA).