Differential Transmission Lines Research Articles

A high-sensitivity 135 GHz millimeter-wave imager by compact split-ring-resonator in 65-nm CMOS

A high-sensitivity 135GHz millimeter-wave imager is demonstrated in 65nm CMOS by on-chip metamaterial resonator: a differential transmission-line (T-line) loaded with split-ring-resonator (DTL-SRR). Due to sharp stop-band introduced by the metamaterial load, high-Q oscillatory amplification can be achieved with high sensitivity when utilizing DTL-SRR as quench-controlled oscillator to provide regenerative detection. The developed 135GHzmm-wave imager pixel has a compact core chip area of 0.0085mm2 with measured power consumption of 6.2mW, sensitivity of −76.8dBm, noise figure of 9.7dB, and noise equivalent power of 0.9fW/HZHz. Millimeter-wave images has been demonstrated with millimeter-wave imager integrated with antenna array.

Electrical Modeling and Characterization of Shield Differential Through-Silicon Vias

An equivalent-circuit model of shield differential through-silicon vias (SDTSVs) in 3-D integrated circuits (3-D ICs) is proposed in this paper. The proposed model is verified using the 3-D full-wave field solver High Frequency Simulator Structure, showing that it is highly accurate up to 100 GHz. Furthermore, a full-wave extraction method for the resistance–inductance–capacitance–conductance (RLCG) parameters of SDTSVs is also proposed in this paper, which can be applied to all of differential transmission lines. It is shown that the results of the RLCG parameters obtained from the full-wave extraction method agree well with that from the analytical calculation up to 100 GHz, further validating the accuracy of the proposed model. Finally, using the proposed model, a deep analysis of electrical characteristics of SDTSVs is carried out to provide helpful design guidelines for them in future 3-D ICs.

Improved Multimode TRL Calibration Method for Characterization of Homogeneous Differential Discontinuities

The multimode thru-reflect-line (TRL) calibration technique is widely applied to characterizing differential discontinuities. However, its accuracy is highly dependent on the inhomogeneity degree of differential transmission lines. In particular, in the case that the calibration structures are immersed in a homogeneous medium where different modes travel with the same propagation constant, the conventional multimode TRL is no longer applicable. To overcome this limitation, a new symmetrical reflect standard with distinct pure-mode reflection coefficients is proposed, and the conventional multimode TRL method is improved based on the assumptions applied to the reflect standard. A group of strip-line calibration kits are tested, and the proposed method is implemented to calculate the de-embedded S-parameters of a symmetrical device-under-test. The experimental results show that, from 20 MHz to 16 GHz, the calibrated pure-mode parameters agree well with the simulation, and the cross-mode parameters are mostly lower than −30 dB. Moreover, using the proposed method, the average measurement error achieves at least 14.8-dB reduction relative to that before calibration, and a maximum improvement of 21.2 dB compared with that of the conventional multimode TRL.

Differential- and common-mode radiofrequency interference filters based on complementary split ring resonators: a conduction and radiation impact analysis

This paper aims to analyse the design techniques of differential transmission lines loaded with metamaterials. Specifically, complementary split-ring resonators were etched on the ground plane of a microstrip transmission line in order to mitigate both differential- and common-mode propagation in differential signalling. Several prototypes were manufactured and characterised in printed circuit boards. The topologies under test were measured and compared as radiofrequency interference filters, taking into account frequency response, signal integrity, and near- and far-field radiation impact with regard to a reference (solid ground) board.

高速差動配線における低コモンモードノイズ設計手法

高速差動配線における低コモンモードノイズ設計手法

High-Sensitivity CMOS Super-Regenerative Receiver with Quench-Controlled High-<formula formulatype="inline"><tex Notation="TeX">$Q$</tex> </formula> Metamaterial Resonator for Millimeter-Wave Imaging at 96 and 135 GHz

High-sensitivity super-regenerative receivers (SRXs) are demonstrated at 96 and 135 GHz, respectively, in this paper. They are based on high-Q quench-controlled metamaterial resonators with a differential transmission line loaded with a split-ring resonator (DTL-SRR) and a differential transmission line loaded with a complementary split-ring resonator (DTL-CSRR) in 65-nm CMOS. High-Q oscillatory amplifications are established by the sharp stopband introduced by metamaterial resonators. As such, high detection sensitivity is achieved for SRXs at millimeter-wave regions. The fabricated 96-GHz DTL-CSRR-based SRX has a compact core chip area of 0.014 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> with measured power consumption of 2.8 mW, sensitivity of -79 dBm, noise figure (NF) of 8.5 dB, and noise equivalent power (NEP) of 0.67 fW/√(Hz). The fabricated 135-GHz DTL-SRR-based SRX has a compact core chip area of 0.0085 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> with measured power consumption of 6.2 mW, sensitivity of -76.8 dBm, NF of 9.7 dB, and NEP of 0.9 fW/√(Hz). Compared to the conventional SRX with an LC-tank-based resonator at similar frequencies, the proposed SRXs have 2.8~4 dB sensitivity improvement and 60% smaller area. The integrated SRXs are also demonstrated for the imaging applications.

UHD급 영상패턴 제어를 위한 전송선로의 신호 왜곡현상 분석

최근 초고화질(4K-UHD) 영상 시스템의 신호전송은 비압축 고속 데이터로 전송되며 고속 신호의 인터페이스 구간에 서로 다른 케이블 사이에서 나타나는 EMI, 스큐(skew) 문제로 인하여 영상신호의 왜곡, 지터 등으로 시스템 구현에 한계가 있다. 이와 같이 비압축 고속 데이터를 고속전송하기 위하여 V-by-One HS 인터페이스 기법을 적용하여 본 논문에서는 고속 영상신호에 대하여 HSD(High Speed Differential) 전송선로의 신호무결성을 분석하였다. UHD 영상패턴 제어 인터페이스의 PCB 설계 방법을 RF 전송기법으로 적용하였으며 구현된 4K-UHD급 영상패턴 제어 신호발생기의 V-by-One HS 영상신호를 측정한 결과, 전송품질이 고속전송신호규격에 만족함을 보였다. Recently signal transmission of ultra high-definition(4K-UHD) video system is transferred as uncompressed high speed data. However, this has a limit to compose the system because EMI between separate cables of high speed interface section and skew bring distortion of the video signal and jitter. In this paper we applied V-by-One HS interface technique to transfer uncompressed high speed data. We analyzed HSD(High Speed Differential) transmission line signal integrity. Also we applied RF transmission technique instead of UHD video pattern control interface PCB design. When we measured V-by-One HS video signal of designed 4K-UHD class signal generator, We found that the transmission performance has been signal standard.

Reducing glitches when reconstructing four‐port S‐parameters of differential transmission lines from two‐port measurements

ABSTRACTThe origin of the glitches observed in four‐port S‐parameters reconstructed from two‐port measured data is identified, allowing their direct minimization without any data post‐processing. Excellent correlation for the obtained four‐port and mixed‐mode S‐parameters is achieved when confronted with those directly measured using a four‐port network analyzer. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2257–2260, 2014

Common-Mode Noise Reduction Using Asymmetric Coupled Line With SMD Capacitor

In this paper, a bended differential transmission line using the asymmetric coupled line (ACL) with surface mount device (SMD) capacitor is proposed to suppress the common-mode noise. The bended differential transmission line using the ACL with SMD capacitor can greatly reduce the mode conversion from -6.91 to -13.29 dB and the Time-Domain-Through common-mode noise from 0.063 to 0.023 V as compared with the bended differential transmission line using the right-angle bend. Also, the differential-mode transmission is increased and the small differential-mode reflection is maintained. To verify the simulation results, measurement is done in the frequency and time domains where the measurement results are in good agreement with the simulation results.

Rotary Traveling-Wave Oscillator With Differential Nonlinear Transmission Lines

A methodology for the harmonic-balance analysis and design of rotary-traveling wave oscillator is presented. Two different implementations are compared. The first one is the standard configuration based on a distributed transmission lines. The second one is a new configuration based on a differential nonlinear transmission line (NLTL), which enables the generation of square waveforms with reduced number of stages, while still maintaining the capability to produce multiphase signals. The possible coexistence of oscillation modes is investigated with a detailed bifurcation analysis versus practical parameters such as the device bias voltage. The phase-noise spectrum is predicted from the variance of the common phase deviation. The parameters that determine this variance are identified with the conversion-matrix approach. The two prototypes, based on a distributed transmission line and a differential NLTL, have been manufactured and characterized experimentally, obtaining very good agreement between simulations and measurements.

Differential transmission lines with surface plasmon polaritons at low frequencies

A new kind of differential microstrip lines by introducing periodic subwavelength corrugation in the edge, which is able to support low-frequency spoof surface plasmon polaritions, is proposed. The surface current distribution of the subwavelength periodic corrugated microstrip is numerically analysed. A kind of differential to single-ended microstrip coupling circuit is designed to investigate the ability of suppressing the crosstalk of such a subwavelength periodic corrugated differential pair. Experimental results show that such a structure can be utilised to effectively suppress crosstalk, and to reduce the transformation between differential-mode and common-mode signals.

Reduction of common-mode excitation on a differential transmission line bend by imbalance control

Reduction of common-mode excitation on a differential transmission line bend by imbalance control

Signal Integrity Analysis of High-Speed Signal Connector USB3.0

High-speed signal connector has become a key factor of the signal transmission quality in telecommunications and data communications system. Signal integrity of connector is an inevitable problem. This paper based on the theory of differential transmission lines and Multimode S-Parameters, analyzed the USB3.0 connector signal integrity. And use 3D simulation software CST to build model and analyze the relationship of signal integrity and connectors geometry.

Frequency and Time-Domain Performance of LTCC Transmission Lines Fabricated Using Multiple Printing Techniques

The many advantages of low temperature co-fired ceramic (LTCC) materials are increasing their use in multi-layer systems containing multiple high-frequency / high-speed digital interconnects. Although construction of such interconnects is possible with current fabrication techniques, the loss exhibited by transmission lines at high frequencies limits their application by increasing system power consumption or requiring complex transceivers. Use of non-standard metal printing processes provides one possibility for realizing lower insertion loss desired for these interconnects. We have fabricated and evaluated representative single-ended and differential stripline transmission line structures using single, double, and mirror printing techniques for Ag metalization in DuPont 9K7 LTCC, to explore their suitability for high-frequency/high-speed applications. Discussion of analysis performed on cross-sections of these structures to determine post-firing geometry, as well as the level of fabrication control afforded over these parameters will be presented. To predict their performance for high-speed interconnects, 3D electromagnetic (3DEM) simulation models for characterizing the frequency performance of single-ended and differential structures have been also been developed. These 3DEM models have also been used in time domain simulations to verify digital signal capability by demonstrating structure performance at data rates exceeding 25 Gbps. Measurements of fabricated structures corresponding to the 3DEM models have also been performed in both the time and frequency domain and will be compared to the simulation results to confirm 3DEM model accuracy. The culmination of results from simulation and measurement will be used to present the differences, advantages, and disadvantages of each fabrication technique.

Hybrid differential transmission line bend to suppress common‐mode noise

A new type of differential transmission line with a bend is proposed to reduce differential-to-common-mode conversion noise for high-speed digital circuits. The hybrid structure consists of alternating edge-coupled and broadside-coupled transmission line sections which has the effect of reducing the mode conversion noise by at least 20 dB up to 10 GHz, whereas the differential insertion loss remains low. In addition, in the time domain, the common-mode noise is lower than the conventional edge-coupled differential transmission line bend. The performance of the proposed structure with a bend is demonstrated both numerically and experimentally. The measurement results agree very well with the simulation results from the three-dimensional full-wave solver.

A Two-Step Perturbation Technique for Nonuniform Single and Differential Lines

A novel two-step perturbation technique to analyze nonuniform single and differential transmission lines in the frequency domain is presented. Here, nonuniformities are considered as perturbations with respect to a nominal uniform line, allowing an interconnect designer to easily see what the effect of (unwanted) perturbations might be. Based on the Telegrapher's equations, the proposed approach yields second-order ordinary distributed differential equations with source terms. Solving these equations in conjunction with the pertinent boundary conditions leads to the sought-for currents and voltages along the lines. The accuracy and efficiency of the perturbation technique is demonstrated for a linearly tapered microstrip line and for a pair of coupled lines with random nonuniformities. Moreover, the necessity of adopting a two-step perturbation in order to get a good accuracy is also illustrated.

Design of High-Q Millimeter-Wave Oscillator by Differential Transmission Line Loaded With Metamaterial Resonator in 65-nm CMOS

In this paper, low phase-noise, low-power, and compact oscillators are demonstrated at the millimeter-wave region based on differential transmission lines (DTLs) loaded with metamaterial resonators. There are two types of metamaterial resonators explored: split-ring resonators (SRRs) and complementary split-ring resonators (CSRRs). By creating a sharp stopband at the resonance frequency from a loaded SRR or CSRR, the backward electrical-magnetic (EM) wave is reflected to couple with the forward EM wave to form a standing EM wave in the DTL host, which results in a high- $Q$ and low-loss millimeter-wave resonator with stable EM energy stored. The resulting DTL-SRR and DTL-CSRR resonators are deployed for designs of millimeter-wave oscillators in 65-nm CMOS. The measurement results show that one DTL-SRR-based oscillator works at 76 GHz with power consumption of 2.7 mW, phase noise of $-{\hbox{108.8 dBc/Hz}}$ at 10-MHz offset, and figure-of-merit (FOM) of $-{\hbox{182.1 dBc/Hz}}$ , which is 4 dB better than that of a 76-GHz standing-wave oscillator implemented on the same chip. Moreover, another DTL-CSRR-based oscillator works at 96 GHz with power consumption of 7.5 mW. Compared to the existing oscillators with an LC-tank-based resonator, the DTL-CSRR oscillator has much lower phase noise of $- {\hbox{111.5 dBc/Hz}}$ at 10-MHz offset and a FOM of $- {\hbox{182.4 dBc/Hz}}$ .

A 96-GHz Oscillator by High-$Q$ Differential Transmission Line loaded with Complementary Split-Ring Resonator in 65-nm CMOS

A 96-GHz CMOS oscillator is demonstrated in this brief with the use of a high-Q metamaterial resonator. The proposed metamaterial resonator is constructed by a differential transmission line (T-line) loaded with complementary split-ring resonator engraved on the T-line. A negative real part of permittivity, i.e., , is observed near the resonance frequency, which introduces a sharp stopband and, thus, leads to a high-Q resonance. This brief is the first in literature to explore CMOS on-chip metamaterial resonator for oscillator design at the millimeter-wave frequency region. Compared with the existing oscillators with a LC-tank-based resonator at around 100 GHz, the proposed 96-GHz oscillator with high- metamaterial resonator shows much lower phase noise of 111.5 dBc/Hz at 10-MHz offset and figure-of-merit of 182.4 dBc/Hz.

Design, implementation and measurement of a 120 GHz 10 Gb/s phase-modulating transmitter in 65 nm LP CMOS

A novel mm-wave phase modulating transmit architecture, capable of achieving data rates as high as 10 Gb/s is presented at 120 GHz. The circuit operates at a frequency of 120 GHz. The modulator consists of a differential branchline coupler and a high speed 4-to-1 analog multiplexer with direct digital input. Both a QPSK as well as a 8QAM constellation are supported. To achieve high output power, a 9-stage power amplifier is designed and connected to the multiplexer output. The complete chip is integrated in a 65 nm low power CMOS technology. Capacitive neutralization is used to achieve high gain and good stability for the MOS devices. Also, various differential transmission line topologies are investigated to achieve high performance in terms of loss and area consumption.

The Reliability Study of a High density Multi Chip Packaging with Folding Flexible Substrate

In this century, the IC packaging technology continues to make progress at astounding rate to meet the increasing requirements in many fields[1]. High density packaging is normally achieved by using various chip and/or package staking. Due to itsunique bending characteristics, flex substrate has become an ideal candidate for high density 3D packaging, especially applied for the packaging of medical products[2,3]. In this paper, we focus on the process development details of a flexible package, and investigate the main reliability problems through a series of reliability tests. There were three chips in the 3D flexible packaging structure used in our experiments. The center chip had a larger size of 5.95à —4.35mm2, while the edge ones were smaller and had the same size of 1.95à —1.95mm2. The thickness of all the three chips was the same, 200ÃŽ ¼m. All the chips had daisy chain testing structure. The ball diameter and pitch of the bumps were 250ÃŽ ¼m and 400ÃŽ ¼m, respectively. The substrate was a double-layer non-gel flexible substrate, which had polyimide as the core material (dielectric constantâ ‰ ˆ4). The substrate had a dimension of 16.9mmà —5.5mm2, and a total thickness of 80ÃŽ ¼m. Differential transmission line and DC test pads were designed in the testing circuit for high frequency signal and DC electric test. The dimension of the 3D package after folding was about 6à —6.6à —1.3mm3. The assembly process flow is as follows: All the chips were connected to a flexible substrate by using flip-chip bonding process. After underfilling was applied and cured, the two edge chips were folded and stacked onto the center chip. Then encapsulation and BGA ball dropping were followed. By flexible folding and chip stacking, the overall package size was reduced. We chose an epoxy based material as underfilling and encapsulation. X-ray check and c-scan test showed that the encapsulation had no voids in most samples. Autoclave (RH 95%, 125Ã’ °C, 96 hours) and multireflow (260â „ ƒ for 5 times) test were designed to assess the flexible structure and check the package reliability. Electrical measurements were performed to monitor and check the REL output. Some of the important electrical test results are summarized below: (1) After the multireflow test, some of the 2D unfolding samples showed open circuit in DC test, especially around the vicinity of the larger chip in the center. The DC test results of 3D samples showed no significant change after multireflow, while cross-section image showed no delamination in these area. (2) After the autoclave test, open circuit could be observed in most 2D unfolding samples near the region of the larger chip in the center, while open circuit could be seen in some smaller chip region too. For the other good parts, resistance showed an increase of 150–200% than before. The DC test results of 3D samples showed no significant change after autoclave, and the cross-section image showed no delamination in these area. (3) It could be presumed that the center region of the large chip was the weakest link of this package. 3D folding and encapsulation had reinforcement action on the flexible substrate.