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This article provides an overview of the use of millimeter-wave (mmWave) imaging in security scanning systems. MmWave scanners are capable of detecting both metallic and nonmetallic threats, making them more effective than traditional metal detectors. The article explains the functioning of mmWave imaging, including the role of transmitters, receivers, and antennas. It introduces a chipset developed by Analog Devices that utilizes edge processing to handle the large amount of data generated by mmWave scanners. The chipset includes a transmitter (ADAR2001) and a receiver (ADAR2004) that work together to create a complete mmWave scanner. The article highlights the importance of fast switching times and the ability to differentiate between different objects in security scanning scenarios. It also discusses the various components of the chipset, such as the ADAR2001 quad transmitter, ADAR2004 quad receiver, AD9083 16-channel ADC, and ADF4368 PLL/VCO chipset, which can be used to develop advanced mmWave security scanners. The chipset offers integrated state machines and on-chip digital downconversion, which enhance processing efficiency. The article further explains the sequencing and operation of these devices, as well as the advantages of utilizing multiple transmit frequencies. Additionally, the wide frequency range and high channel density of the chipset suggest potential applications beyond security imaging. [Extracted from the article]

The article presents guidelines on how system engineers can understand the contribution of individual components to the overall performance of a device. For a three-stage signal chain, system engineers can use cascaded noise factor, gain, composite third-order intercept (IP3) and 1 dB Compression (P1dB) equations. System engineers can use the ADIsimRF radio frequency (RF) signal chain calculator from Analog Devices.

The article discusses the ability of highly integrated digital variable-gain amplifiers (DVGAs) from Analog Devices Inc. to provide precise control of amplitude levels over a 31.5-dB range through one GHz for applications in wireless infrastructure equipment in the U.S. It states that variable gain is used to reduce signal levels when a large unwanted blocking signal present. Meanwhile, digital step attenuators (DSAs) are used to adjust the static gain of a receiver.

Because of their fundamental rectifying characteristic, diodes have been used to generate DC voltages that are proportional to AC and RF signal levels for as long as there have been diodes. This article compares the performance of diodebased RF/microwave detectors with integrated circuit alternatives. Topics include transfer function linearity, temperature stability and interfacing with analog-to-digital converters. [ABSTRACT FROM AUTHOR]

The article provides information on the benefits that wireless transmitters can derived from measurement and control of radio frequency (RF) power. It has been noted that the RF power levels of wireless transmitter high-power amplifiers (HPAs) must be monitored and controlled due to regulatory requirements. The monitoring and controlling of RF power can result in improved transmitter spectral performance as well as significant savings in operating cost for an HPA.

Explains the uses of logarithmic amplifier (logamp) technology in detecting catastrophic events such as the sudden increase in voltage standing-wave ratio that might occur when an antenna breaks. Application of logamp in the global system for mobile communication transmitter; Use of a closed-loop architecture; Illustration of a wireless transmitter with an auxiliary receiver in which the signal being transmitted is sampled and mixed back down to baseband; Means by which calibration is performed.

Examines the direct-conversion approach for multicarrier WCDMA and CDMA2000. Comparison of single-carrier and multiple-carrier transmitter spectra; Key advantage of the super heterodyne architecture over a direct-conversion approach; Goal of the transmitter signal-chain designer.

Presents a practical guide to designing low-power, low-distortion circuits for cable modem systems. Popularity of High Bit-rate Digital Subscriber Line (HDSL) in providing full-duplex data communication; Use of Asymmetrical Digital Subscriber Line (ADSL) in Internet applications; Ensuring reliability of line-drivers; Challenges of line driving in a single-supply environment. INSET: Demystifying dBm: A primer on power..

Examines specifications on high-speed operational amplifiers (op amps) and its applications. Discussion of bandwidth and video; Total harmonic distortion (THD) versus spurious-free dynamic range (SFDR); Signal swing and distortion.

Presents a guide outlining how to design low-power, low-distortion circuits for XDSL, and cable modem systems. Information on broadband communications applications; Why bipolar technology is favored by integrated circuit designers; Success of transmitting data on High Bit-rate Digital Subscriber Lines.

Focuses on taking advantages of fast rail-to-rail op amplifiers in low-voltage systems. Protection of analog inputs; Gains and adjustments; Signal distortion; Design examples; Video line drivers; Loading conditions. INSET: Making the swing..

Focuses on the importance of line driving in wired digital communications applications. Requirements of the line driver; Problems which affect digital communications; Components of transmitters which are used in digital communication.

Focuses on the design for making a linear radio-frequency power detector. Use of modulation schemes in the logarithmic amplifiers; Application of the AD8361 high-frequency true-power detector; Structure of power detection.

Focuses on the implementation of an automatic gain control (AGC) amplifier using a voltage-controlled amplifier (VCA) and a single supply voltage-feedback amplifier configured as an integrator. Direct current representation of the VCA output signal; Lower trace illustration of the voltage at the AGC amplifier's output.