Mohamed Hamouda

Ultra-wideband active array imaging for biomedical diagnostics

Ultra-wideband active array imaging has proven extremely valuable for biomedical diagnostics. At the same time, the underlying technologies have achieved a high degree of maturity. Across institutions, we have merged our expertise in M-sequence radar systems, antennas, low-noise and high-power circuitry, to devise an UWB MIMO radar system for breast tumour localisation. Recent progress in UWB imaging and hardware for active antenna arrays is presented.

A compact analog active time delay line using SiGe BiCMOS technology

This work discusses the design of a 60ps delay element for UWB analog signals ranging from 0.05 up to 8GHz. The design is implemented using active architecture design which have the advantage of being very compact in area compared to the passive architectures. The proposed architecture is flexible and can be cascaded to have a delay of up to 200ps with a maximum insertion loss of 3dB. The circuit is designed using a low cost 0.25μm 95GHz fmax SiGe-HBT-BiCMOS process technology consuming a power of 121mW. The estimated consumed area of the circuit is 0.49mm2.

System Analysis of a Phased-Array Radar Applying Adaptive Beam-Control for Future Automotive Safety Applications

In this contribution, we present a novel beam-control approach for automotive phased-array radar frontends. Since radar sensors are considered to be one of the means to enable future advanced safety functionality, we previously developed a system simulation environment that incorporates all involved domains and calculates all relevant high-level effects accurately. Subsequently, a generic phased-array FMCW radar frontend has been implemented and parameterized according to state-of-the-art SiGe components operating in the 77 GHz band. To demonstrate the advantages of an adaptively controlled beam for future safety applications, it is focused on curved traffic situations, which are calculated in a co-simulation incorporating a 3D-raytracer. A novel method for the control of the antenna characteristic is derived, which takes the specific curve geometry into account, and predictive enhancement features applied to it are elucidated, before their utilization and the resulting increase of system performance is computed. By adaptively coupling the radar sensor to the steering angle, thus directing its beam together with the ego-vehicle into the curve, its measurement range can be distinctly increased, which is providing more time for the safety system to react. This set of facts is first examined in a static view, by regarding only some specially selected timesteps, before a thorough analysis of the complete traffic scenario reveals the systems advantages from a dynamic point-of-view. As a result, the performance improvement of phased-array frontends applying adaptive beam-control compared to those with body-fixed nonsteerable beams is proven. Moreover, some results which are to be expected from such an advanced system, in case its full potential is evolved by implementing a scanning functionality, are provided as an outlook on future developments.

A double bandpass N-path filter for LTE carrier aggregation receivers in 28nm CMOS

A tunable double bandpass integrated filter is introduced. The filter is designed based on the impedance transfer identity of the N-path filtering. The filters dual bandpass nature, makes it suitable to be employed as a high Q filter at the input of LTE receivers. It can be used to suppress out-of-band blockers in the non-contiguous carrier aggregation mode. Each of the two passbands can be tuned to be centered at each of the two LTE carriers. The design is simulated for LTE band 2 and the simulation results showed blocker suppression of 10 dB for blockers at the duplex distance and 12 dB of suppression for blockers at double the duplex distance.

A cross correlation based clock synchronization up to 10GHz for ultra-wideband sensing systems

This paper presents a cross correlation based synchronization architecture between the clock of the receiver and the transmitter for ultra-wideband radio systems. The designed architecture is based on M-sequence signals instead of the conventional impulse signals. The M-sequence generator and the analog correlation circuit are fabricated on chip using a low cost 0.25μm 95GHz fmax SiGe-HBT-BiCMOS process technology. The chip is mounted on a printed circuit board (PCB) with a commercial voltage controlled oscillator. The measurement results show a low phase noise of the VCO of -66dBc/Hz at 1KHz offset and an rms jitter of 1.6ps for a 10GHz frequency and a bit rate of 20Gb/s.

High precision wireless synchronization receiver for M-sequence UWB Radio systems

This work deals with M-sequence UWB Radio architectures for high-precision indoor localization and low data rate radio transmission. So far, UWB M-sequence devices were only used in Radar mode which applies wired synchronization between transmitter and receiver. Radio systems have different architecture since receiver and transmitter are spatially separated from each other. This paper focuses on the phase and frequency synchronization between the clock of the transmitter and receiver. The proposed architecture deals with 10 gigachips per second achieving a high frequency bandwidth ranging from DC upto 5GHz or consequently from 5GHz to 15GHz depending on the device structure. It is very costly and power demanding to process such signals in the digital domain to perform the synchronization. Thus, a low power and low cost technique is introduced using analog blocks for the synchronization achieving a maximum time error of 5ps between the received and reference M-Sequence waveforms.

A 20-Gbps low jitter analog clock recovery circuit for ultra-wide band Radio systems

This work describes the design of high speed clock recovery circuit for UWB M-sequence based Radio systems in the analog domain to avoid the high power consumed in the analog to digital converters (ADC). The clock recovery circuit depends on two modes, the coarse tuning mode and the fine tuning mode for final locking and tracking. It is illustrated, using this method, that low jitter is achieved while maintaining high acquisition range up to the tuning range of the VCO. The method depends on using a reference M-sequence in the receiver similar to the one used in the transmitter and an analog correlation circuit. The circuits are designed using a low cost 0.25μm 95GHz fmax SiGe-HBT-BiCMOS process technology consuming an estimated power of 185mW.

Ultra wide band power amplifier for miniaturized antennas

This work presents the design and the manufacturing of an ultra wide band power amplifier specially designed to deliver maximum available power to a miniaturized antenna developed for biomedical applications. The chip is designed using a low cost 0.25μm 95GHz fmax SiGe-HBT-BiCMOS process technology. The amplifier operates from 1.5GHz up to 10GHz that gives the advantage of having high resolution radar system. The amplifier has a low output impedance to match the antennas impedance. The measurements of the chip are performed in 50Ω system to extract the scattering parameters and simulate it with the antenna. The estimated gain is 11dB with input reflection coefficient less -10dB and serves as a matching network between the 50Ω input and the low impedance antenna. The maximum estimated output power of the amplifier is 5.5dBm at frequency 8GHz with power added efficiency of 3%. The chip consumes a low power of 96mW and has an area of 0.84mm2.

A Clock Synchronization for M-Sequence-Based Ultra-Wideband Systems

This paper presents a cross-correlation-based synchronization architecture between the clock of the receiver and the transmitter of ultra-wideband systems. The proposed architecture is based on M-sequence signals instead of the conventional impulse signals. The M-sequence generator and the analog correlation circuit are fabricated on-chip using a low-cost 0.25 μm 95 GHz fmax SiGe-HBT-BiCMOS process technology. The chip is mounted on a printed circuit board (PCB) with a commercial voltage-controlled oscillator (VCO). The synchronization scheme obtains the clock information with a received signal as low as 2 mV peak to peak and minimum input power of -52 dBm at 10 GHz. The power spectrum measurement of the locking VCO shows a low phase noise of -69 dBc/Hz at 1 kHz offset and an rms jitter of 0.93 ps for a 10 GHz frequency and a bit rate of 20 Gb/s. The achieved mismatch between the received and the reference signals is a maximum of 25 ps at signal bandwidth of 10 GHz. The proposed clock recovery system acquires the clock information correctly with different materials placed in the transmission channel.

HaLoS – Integrated RF-Hardware Components for Ultra-Wideband Localization and Sensing

Ultra-Wideband (UWB) sensors exploit very weak electromagnetic waves within the lower microwave range for sounding the objects or processes of interest. The interaction of electromagnetic waves with matter provides interesting options to gain information from a great deal of different scenarios. To mention only a few, it enables the assessment of the state of building materials and constructions, the investigation of biological tissue, the detection and localization of persons buried by rubble after an earthquake or unauthorized people hidden behind walls, and much more [1]. The advantage of such methods consists in their non-destructive and continuously running measurement procedure which may work at high speed and in contactless fashion.