Compact $S$ -/$Ka$-Band CMOS Quadrature Hybrids With High Phase Balance Based on Multilayer Transformer Over-Coupling Technique

This paper presents compact CMOS quadrature hybrids by using the transformer over-coupling technique to eliminate significant phase error in the presence of low-$Q$ CMOS components. The technique includes the inductive and capacitive couplings, where the former is realized by employing a tightly inductive-coupled transformer and the latter by an additional capacitor across the transformer winding. Their phase balance effects are investigated and the design methodology is presented. The measurement results show that the designed 24-GHz CMOS quadrature hybrid has excellent phase balance within ${pm}{hbox{0.6}}^{circ}$ and amplitude balance less than ${pm} {hbox{0.3}}$ dB over a 16% fractional bandwidth with extremely compact size of 0.05 mm$^{2}$. For the 2.4-GHz hybrid monolithic microwave integrated circuit, it has measured phase balance of ${pm}{hbox{0.8}}^{circ}$ and amplitude balance of ${pm} {hbox{0.3}}$ dB over a 10% fractional bandwidth with a chip area of 0.1 mm$^{2}$ .      

$C$ -Band Optical 90$^{circ}$ -Hybrids Based on Silicon-on-Insulator 4 $times$ 4 Waveguide Couplers

We demonstrate 4times4 multimode interference couplers in a silicon-on-insulator rib waveguide technology that enable compact integrated fully passive optical 90deg-hybrid devices with operation across the C-band.     

$n$ -SIFT: $n$ -Dimensional Scale Invariant Feature Transform

We propose the $n$ -dimensional scale invariant feature transform ( $n$-SIFT) method for extracting and matching salient features from scalar images of arbitrary dimensionality, and compare this method's performance to other related features. The proposed features extend the concepts used for 2-D scalar images in the computer vision SIFT technique for extracting and matching distinctive scale invariant features. We apply the features to images of arbitrary dimensionality through the use of hyperspherical coordinates for gradients and multidimensional histograms to create the feature vectors. We analyze the performance of a fully automated multimodal medical image matching technique based on these features, and successfully apply the technique to determine accurate feature point correspondence between pairs of 3-D MRI images and dynamic $3{rm D} + {rm time}$ CT data.      

$L$ -Band Polarization-Independent Reflective SOA for WDM-PON Applications

An $L$-band polarization-independent reflective semiconductor optical amplifier (RSOA) is demonstrated for the first time. Optical gain of greater than 21 dB and gain flatness better than 4 dB is achieved over the $L$-band. The polarization-dependent gain estimated using a polarization resolved spectrum is less than 1 dB over the $L$-band. The measured output saturation power is $-$1.0 dBm and the noise figure (NF) is 10 dB for the packaged device. The 3-dB frequency bandwidth for the device is 1.3 GHz making it suitable for 1.25-Gb/s modulated wavelength-division-multiplexed passive optical network networks. Further, the saturation power and the NF of the RSOA were compared with an SOA of identical length.      

$S$ -Parameter Sensitivities for Electromagnetic Optimization Based on Volume Field Solutions

We propose a sensitivity analysis method that computes the $S$-parameter Jacobian from the volume $bf E$ -field solutions in the frequency domain. The field solutions may be provided by any valid electromagnetic analysis. The computation is a post-process, which is independent from the simulator's grid, system equations, and discretization method. The sensitivity solver uses its own finite-difference grid and a sensitivity formula based on the finite-difference frequency-domain vector Helmholtz equation for the electric field. Its computational overhead is negligible in comparison with the simulation. We use the sensitivity solver in the gradient-based optimization of microwave structures. Significant reduction of the time required by the overall optimization process is achieved. In all design examples, the sensitivities are computed from the field solutions provided by a commercial finite-element simulator.      

A $K$ -Band CMOS Distributed Doubler With Current-Reuse Technique

A $K$-band distributed frequency doubler is developed in 0.18 $mu{rm m}$ CMOS technology. This doubler combines the distributed topology for broadband characteristics and current-reuse technique to improve the conversion gain. The high-pass drain line and high-pass inter-stage matching network are used to obtain a good fundamental rejection. A measured conversion gain of better than ${- 12.3}~{rm dB}$ is obtained, and the fundamental rejection is better than 30 dB for the output frequency between 18 and 26 GHz. The dc power consumption is 10.5 mW with a chip size of 0.55$,times,$0.5 ${rm mm}^{2}$.      

Development of Thin-Film Liquid-Crystal-Polymer Surface-Mount Packages for $Ka$ -Band Applications

In this paper, we present the design and development of thin-film liquid-crystal-polymer (LCP) surface-mount packages for $Ka$ -band applications. The packages are constructed using multilayer LCP films and are surface mounted on a printed circuit board (PCB). Our experimental results demonstrate that the package feed-through transition including a PCB launch and bond wires achieve a return loss of better than $-$20 dB and an insertion loss of less than 0.4 dB around $Ka$ -band. We achieve a measured port-to-port isolation of the package to be more than 45 dB across the $Ka$-band. We demonstrate the package feed-through circuit model by comparing the simulation of model and bare die measurement data to a packaged amplifier measurement. Finally, we report an LCP cavity that has a measured fine leak rate of ${hbox{3.6}}times {hbox{10}}^{-8} {hbox{atm}}cdot{hbox{cc/s}}$ .      

Integrated LTCC Synthesizer and Signal Converter Modules at $K$ -Band

We report on fully integrated K -band synthesizer and signal converter modules. The designs are realized in low-temperature co-fired ceramics, making extensively use of the multilayer features and advanced capabilities of this substrate system. The interior packaging technology exclusively utilizes flip-chip mounting of bare semiconductors. As a key element a low phase noise synthesizer is integrated in a hermetic surface mount package of 8.7 mm times 15.8 mm, achieving an output power of more than 6 dBm in a range between 19.58-20.2 GHz. The stabilization is achieved by a fractional-N phase-locked loop, all required components being integrated inside and on top of the package. The synthesizer design is extended to dual-sideband and single-sideband converters by including mixers and couplers in the same package.     

A 100 $mu$ W 128 $times$ 64 Pixels Contrast-Based Asynchronous Binary Vision Sensor for Sensor Networks Applications

An ultra-low power 128 $times$ 64 pixels vision sensor is here presented, featuring pixel-level spatial contrast extraction and binarization. The asynchronous readout only dispatches the addresses of the asserted pixels in bursts of 80 MB/s, significantly reducing the amount of data at the output. The pixel-embedded binary frame buffer allows the sensor to directly process visual information, such as motion and background subtraction, which are the most useful filters in machine vision applications. The presented sensor consumes less than 100 $muhbox{W}$ at 50 fps with 25% of pixel activity. Power consumption can be further reduced down to about 30 $muhbox{W}$ by operating the sensor in Idle-Mode, thus minimizing the sensor activity at the ouput.      

Design of $X$ -Band RF CMOS Transceiver for FMCW Monopulse Radar

In this paper, an X-band CMOS single chip integrating 16 building blocks is developed for frequency modulation continuous wave radar application. The quadrature and monopulse transceiver consists of a voltage-controlled oscillator, amplifiers, Wilkinson power dividers, 90deg hybrid low-noise amplifiers, rat-race hybrid, a single-pole double-throw switch, an active bandpass filter (BPF), and mixers. The transceiver is fabricated in a standard mixed-signal/RF bulk 0.18-mum CMOS technology with a chip area of 2.6 mm 3.3 mm, including contact pads. The transceiver is implemented by meandered complementary-conducting-strip transmission lines demonstrating their capability of miniaturizing circuits such as 90deg hybrid and rat-race hybrid with 95% and 98% size reduction compared to the prototype designs, respectively. The active BPF consumes 4.5 mW achieving 0-dB insertion loss at the passband. The total power consumption of the transceiver is 0.35 W. Output power of the transmitter is 1 dBm with a 35-dB second harmonic suppression. Moreover, the on-chip isolations between T/R in this compacted transceiver are more than 60 dB. The measured receiver gain and NF are -4.5 and 11.5 dB, respectively. Finally, the obtained in-phase and quadrature signals demonstrate 0.6-dB amplitude and 7deg phase imbalance.     

A Reformulation and Stability Study of TRL and LRM Using $S$ -Parameters

This paper derives a unified thru, reflect, match (TRL) and line, reflect, match (LRM) calibration algorithm using $S$-parameters instead of traditional $T$-parameters. The advantage of this approach is that we get a solution where the LRM is an integral part of the TRL algorithm. The expression for the transmission coefficient of the line standard has the convenient property that, in many cases, the transmission coefficient is obtained directly without a need for a root choice.      

Modified Half-Size Test Matrix for Robust Passivity Assessment of $S$ -Parameter Macromodels

This letter presents a modified algebraic passivity test to check if an $S$-parameter based macromodel with symmetric scattering matrix is passive or not. To construct the passivity test matrix, the inversion of another matrix is required that can possibly be singular. If this is the case, such methods will fail since they cannot be applied directly. This letter proposes an elegant solution to deal with this problem. The effectiveness of the approach is illustrated by two numerical examples.      

180$^{circ}$ and 90$^{circ}$ Phase Shifting Networks With an Octave Bandwidth and Small Phase Errors

A new phase shifting network for both 180 $^{circ}$ and 90 $^{circ}$ phase shift with small phase errors over an octave bandwidth is presented. The theoretical bandwidth is 67% for the 180$^{circ}$ phase bit and 86% for the 90$^{circ}$ phase bit when phase errors are $pm 2^{circ}$. The proposed topology consists of a bandpass filter (BPF) branch, consisting of a LC resonator and two shunt quarter-wavelength transmission lines (TLs), and a reference TL. A theoretical analysis is provided and scalable parameters are listed for both phase bits. To test the theory, phase shifting networks from 1 GHz to 3 GHz were designed. The measured phase errors of the 180$^{circ}$ and the 90$^{circ}$ phase bit are $pm 3.5^{circ}$ and $pm 2.5^{circ}$ over a bandwidth of 73% and 102% while the return losses are better than 18 dB and 12 dB, respectively.      

A Phase-Locked Loop With Injection-Locked Frequency Multiplier in 0.18-$mu{hbox{m}}$ CMOS for $V$ -Band Applications

In this paper, a novel CMOS phase-locked loop (PLL) integrated with an injection-locked frequency multiplier (ILFM) that generates the $V$-band output signal is proposed. Since the proposed ILFM can generate the fifth-order harmonic frequency of the voltage-controlled oscillator (VCO) output, the operational frequency of the VCO can be reduced to only one-fifth of the desired frequency. With the loop gain smaller than unity in the ILFM, the output frequency range of the proposed PLL is from 53.04 to 58.0 GHz. The PLL is designed and fabricated in 0.18-$mu{hbox{m}}$ CMOS technology. The measured phase noises at 1- and 10-MHz offset from the carrier are $-$ 85.2 and $-{hbox{90.9 dBc}}/{hbox{Hz}}$, respectively. The reference spur level of $-{hbox{40.16 dBc}}$ is measured. The dc power dissipation of the fabricated PLL is 35.7 mW under a 1.8-V supply. It can be seen that the advantages of lower power dissipation and similar phase noise can be achieved in the proposed PLL structure. It is suitable for low-power and high-performance $V$-band applications.      

A $W$ -Band Photonic Transmitter/Mixer Based on High-Power Near-Ballistic Uni-Traveling-Carrier Photodiode (NBUTC-PD)

In this letter, we demonstrate a $W$-band photonic transmitter/mixer fabricated by the flip-chip bonding of a high-power back-illuminated near-ballistic uni-traveling-carrier photodiode (NBUTC-PD) and an end-fire quasi-Yagi antenna on an AlN substrate. This end-fire and directional antenna design eliminates the need for the integration of an additional Si-lens into the antenna for directional power transmission. The high bias dependent nonlinearity of the integrated NBUTC-PD means that the bias modulation technique can be used to directly up-convert the intermediate-frequency signal to a millimeter-wave signal at $W$ -band without using a costly high-speed optical modulator. A reasonable detected power ($-$ 17 dBm at 106 GHz) can be achieved with the demonstrated device with a high-output photocurrent (30 mA) and a low internal-conversion loss ($-$2.4 dB) between the radio-frequency and local-oscillator signals at $W$-band.      

$varepsilon$ -Optimal Non-Bayesian Anomaly Detection for Parametric Tomography

The non-Bayesian detection of an anomaly from a single or a few noisy tomographic projections is considered as a statistical hypotheses testing problem. It is supposed that a radiography is composed of an imaged nonanomalous background medium, considered as a deterministic nuisance parameter, with a possibly hidden anomaly. Because the full voxel-by-voxel reconstruction is impossible, an original tomographic method based on the parametric models of the nonanomalous background medium and radiographic process is proposed to fill up the gap in the missing data. Exploiting this ldquoparametric tomography,rdquo a new detection scheme with a limited loss of optimality is proposed as an alternative to the nonlinear generalized likelihood ratio test, which is untractable in the context of nondestructive testing for the objects with uncertainties in their physical/geometrical properties. The theoretical results are illustrated by the processing of real radiographies for the nuclear fuel rod inspection.     

Architectural Optimizations for Low-Power $K$ -Best MIMO Decoders

Maximum-likelihood (ML) detection for higher order multiple-input–multiple-output (MIMO) systems faces a major challenge in computational complexity. This limits the practicality of these systems from an implementation point of view, particularly for mobile battery-operated devices. In this paper, we propose a modified approach for MIMO detection, which takes advantage of the quadratic-amplitude modulation (QAM) constellation structure to accelerate the detection procedure. This approach achieves low-power operation by extending the minimum number of paths and reducing the number of required computations for each path extension, which results in an order-of-magnitude reduction in computations in comparison with existing algorithms. This paper also describes the very-large-scale integration (VLSI) design of the low-power path metric computation unit. The approach is applied to a 4 $times$ 4, 64-QAM MIMO detector system. Results show negligible performance degradation compared with conventional algorithms while reducing the complexity by more than 50%.      

Plasmon-Waveguide Interband Cascade Lasers Near 7.5 $mu$ m

Broad-area plasmon-waveguide interband cascade lasers with emission wavelengths near 7.5 mu m were demonstrated at temperatures up to 121 K in continuous-wave mode. Their threshold current densities and voltages varied from 72 A/cm² and 2.1 V at 84 K to 400 A/cm² and 2.7 V at 121 K, showing very efficient use of bias voltage (e.g., voltage efficiency of about 90% at 84 K) at this long wavelength. These plasmon-waveguide lasers also operated in pulsed mode at temperatures up to 165 K with emission wavelengths near 7.6 mum and threshold current density of 1100 A/cm².