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This paper presents a model of direct delta-sigma receiver (DDSR) and methodology for theoretical transfer function (TF). The theoretical analysis is carried out by modeling the key elements of the DDSR, including the N-path filter, down-conversion mixer, baseband delta sigma modulator (DSM) and FIRDACs in order to optimize the loop filter coefficients. The contribution of different noise sources...
This Article is reporting implementation and verification of the base-band equivalent RF models which is used in link level simulations with demodulator model such as Nokia's Wireless Modem (NWM) and ST Ericsson modem link simulators. The model represents the chain of filtering, amplification and is responsible for the realization of the selectivity of the canal. The transceiver is constituted by...
A high gain, wide band (2–10GHz) but low noise mixer is presented and demonstrated. It uses a Gilbert type folded structure with an active balun as the input trans-conductance stage and a PMOS switch stage. Because of the structure, each stage can be separately set its bias current to achieve high gain and low noise. The implemented circuit in the 0.18um CMOS technology exhibits a high conversion...
A low-power, highly linear CMOS double-balanced mixer for UWB applications is presented. The mixer is designed based on well-known folded architecture and also benefits from DC isolation of RF (Radio Frequency) and LO (Local Oscillator) stages. Stacked NMOS-PMOS gm-boosting topology is used in the design of RF stage. To achieve very low power consumption, this stage is biased in sub-threshold region...
A high gain and low-power down conversion mixer for short range wireless applications is designed in 0.18 μm complementary metal oxide semiconductor (CMOS) technology. During the design, we have adopted current-bleeding technique and a folded Gilbert topology. The mixer is tested at two frequencies e.g., 2.4 GHz and 5.2 GHz. Simulation results revealed that under 1.8 V power supply, the proposed mixer...
We describe and discuss some of the current challenges facing radar that result from continued spectral encroachment, which necessitating enhanced robustness to interference, agile waveform-diverse operation, and greater synergy between the signal processing and the physical radar/environment. Subsequently, specific research topics are suggested in which spectrum engineering and waveform diversity...
This paper presents low power tunable active inductors suitable for designing multiband RF front end communication circuit like LNA, BPF and VCO. The active inductor circuit uses PMOS cascode structure as negative transconductor of a gyrator to reduce the noise voltage. Also, this structure provides possible negative resistance to reduce the inductor loss with wide inductive bandwidth and high resonance...
This article illustrates application of a concurrent dual-band RF system for human respiration and heartbeat detection. The system simultaneously operates at 2.4-/5.2-GHz band. Overall performance of the system is studied in ADS (Advanced Design System) simulation platform, wherein measured S-parameters of dual-band subsystems are utilized. In the experimental setup, signals are measured with a human...
Radio Frequency devices produce Unintended Electromagnetic Emissions (UEEs). These emissions have been found to be unique from device to device due to small differences in the physical components that make up the device. The property of uniqueness of UEE has been used to detect and identify the device producing the emission. However, UEEs are low power signals often buried within the noise band, which...
This paper presents architecture and simulation results of the analog part of a multichannel integrated circuit (IC) for optical radiation sensors (visible and infrared light) that can be used in high-speed applications. The complete prototype, called Optical Radiation Readout Circuit (ORRC) is composed of analog front end and moderate-resolution analog-to-digital converter (ADC) included in every...
The performance of an uplink radio signal on millimeter-wave-over-fiber using RF self-homodyned is numerically analyzed. The maximum wireless distance is derived considering the effects of fading in wireless channel and noise, distortion in radio-over-fiber link.
This paper shows the comparison between the simulative evaluation and laboratory measurements of Noise Figure in Remote Keyless Entry (RKE) System working in two variants - 315MHz and 433MHz. The key point is that simulation was made in SPICE-like simulator using the PCB extraction data and models that do not use the telegraphists' equations. The difference between the simulative based values and...
In this paper a proposed CMOS LNA which fabricated with the 0.13um CMOS technology. The amplifier is optimized for Bluetooth applications operating in the 2.4–2.5 GHz band. The inductive degeneration topology used in the LNA provides low noise, high gain and a large IIP3. The LNA consists of two amplifying stages with on-chip inductors and capacitors. Simulation was made by using the Advanced Design...
This paper presents a digital interpolation chain for non-integer variable-ratio sampling rate conversion, targeted to 4G mobile applications. Such a system is needed in all-digital transmitters, where the sampling rate of the digital input to the RF front-end must be an integer fraction of the carrier frequency. A highly configurable architecture is proposed to cope with the flexibility needed in...
A low-noise transimpedance amplifier (TIA) for 2.5 Gb/s family is presented using 0.35 μπι BiCMOS technology. It would be used in radiation detectors to transform the current pulse produced by a photo-sensitive device into an output voltage pulse with a specified amplitude and shape. In this paper the mathematical analysis of the proposed TIA is presented together with a detailed analytical noise...
An innovative method to model, in the early design stage, the behavior of nonlinear analog circuits in the presence of noise is presented. The technique relies on Harmonic Balance analysis and the obtained model does not only efficiently predict the influence of a continuous wave disturbance, it may also be used to quickly estimate the device's behavior while being subjected to amplitude modulated...
We report on the development of a frequency converter frontend that enables 2.4 GHz IEEE 802.11 WLAN devices to operate in unused parts of the UHF spectrum, the socalled TV whitespaces. The new frontend features separate TX and RX paths with automatic directionality switching and in-hardware energy detection. Equipped with a standard antenna port at the input side, and a fully configurable transmit...
In this work, we study a special kind of primary user emulation (PUE) attack, named wireless microphone user emulation (WMUE) attack in white space cognitive radio networks. In WMUE attacks, a malicious user emulates wireless microphone (WM) signals in order to block secondary users. Existing work on WMUE attack detection deals with single channel senario. Although multi-channel WM (MCWM) systems...
This paper analyzes a tradeoff between noise figure, blocker filtering, and noise shaping that is inherent in the recently introduced direct delta-sigma receiver approach. It originates in the competing requirements imposed by the front-end low noise amplifier operating as a transconductor in an N-path GmC integrator and as a voltage pre-amplifier in a closed-loop radio-frequency front-end. A generic...
We demonstrate a linearized ring assisted Mach-Zehnder interferometer (L-RAMZI) modulator in a miniature silicon device. We measure a high degree of linearization, with a Spurious Free Dynamic Range (SFDR) of 105 dB/Hz2/3 at 1GHz.
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