Showing papers by "Anthony Ghiotto published in 2018"

Substrate-Integrated Waveguide Filters Based on Dual-Mode Air-Filled Resonant Cavities

Abstract: This paper presents the design and implementation of a novel class of substrate-integrated waveguide (SIW) filters, based on partially air-filled cavity resonators. Removing the dielectric in a portion of the SIW cavity allows obtaining dual-mode cavities: such cavities represent a doublet, used as the building blocks in the design of filters. A thorough modal analysis of the air-filled resonant cavity based on transmission lines’ representation and a detailed study of the doublet permit to demonstrate a full control of the operation frequency, pass bandwidth, spurious-free region, and position of the transmission zeros of the filter. This paper presents the design, fabrication, and measurement of several two-pole filters based on this concept, with the aim to show the capabilities of the proposed structure and of the design technique. A five-pole filter is also presented, to describe the extension of the proposed approach to higher order filters.

A 12 Gb/s 64QAM and OFDM compatible millimeter-wave communication link using a novel plastic waveguide design

Abstract: In this paper, a 64QAM and OFDM capable CMOS transceiver designed for wireless communications in the 60 GHz band is used in combination of a plastic waveguide to realize a 4m link. The plastic waveguide is made of Teflon (PFTE) and features an innovative design enhancing confinement and propagation robustness compared to literature. The first QPSK communication over plastic waveguide is then demonstrated at a rate of 4 Gb/s. It was even possible to perform 64QAM (12 Gb/s) by using scope direct demodulation instead of the receiver chip. Preliminary results also indicate that OFDM communication is possible as well, further highlighting the versatility of plastic waveguides and paving the way to reconfigurable wireless / wireline use cases.

Self-Temperature-Compensated Air-Filled Substrate-Integrated Waveguide Cavities and Filters

Abstract: In this paper, patent pending self-temperature-compensated air-filled substrate-integrated waveguide (AFSIW) cavities and filters are proposed and demonstrated for high-performance and low-cost components, circuits, and systems on substrate. First, a theoretical multiphysics transmission line model is developed for the synthesis of self-temperature-compensated air-filled cavities. It is determined that temperature compensation can be achieved using an appropriate substrate material and dielectric sidewall slab width. Moreover, a postprocess temperature compensation technique is introduced to counterbalance potential fabrication errors. For demonstration purposes, a self-temperature-compensated first-order AFSIW filter (based on a single cavity) is fabricated and compared to its dielectric-less temperature-uncompensated counterpart. Then, a self-temperature-compensated fourth-order AFSIW filter centered at 21 GHz with 300-MHz bandwidth is designed and fabricated. It achieves a measured unloaded $Q$ -factor of 975 at ambient temperature and a measured central frequency thermal stability as low as 2.26 ppm/°C at −40 °C and 1.67 ppm/°C at 80 °C (without using any postprocess tuning), compared to −17.4 ppm/°C at −40 °C and −18.38 ppm/°C at 80 °C for its dielectric-less temperature-uncompensated counterpart.

Slab Air-Filled Substrate Integrated Waveguide

Abstract: The slab air-filled substrate integrated waveguide (SAFSIW) is presented as a compromise between the high performance air-filled substrate integrated waveguide (AFSIW) and low profile dielectric-filled substrate integrated waveguide (DFSIW). Both theoretical and experimental studies are presented in order to investigate SAFSIW structures. To the authors' best knowledge, this is the first time that an SAFSIW-to-DFSIW transition is reported. A 90° phase shifter based on SAFSIW and a patent pending mounting process is also introduced. Measured results show a very high figure of merit (FoM) over the Ka-band. A phase difference of $\mathbf{86}\pm \mathbf{5}.\mathbf{4}^{\pmb{\circ}}$ , an amplitude imbalance of $\mathbf{0}.\mathbf{05}\pm \mathbf{0}.\mathbf{15}\ \mathbf{dB}$ and a FoM of $\mathbf{457}^{\pmb{\circ}}/\mathbf{dB}$ are obtained.

Fabrication-Tolerant Reconfigurable AFSIW Filters Based on Through-Hole Mounted Metallic Posts for Versatile High Performance Systems

Abstract: A novel structure of air-filled substrate integrated waveguide (AFSIW) filters based on through-hole mounted metallic posts is presented. It is based on standard and low-cost printed circuit board (PCB) process, through-hole technology and FR-4 substrate. First, a theoretical study of coupling windows for the synthesis of the proposed filter topology is introduced. Then, for demonstration purposes, two four-order bandpass filters with center frequency of 20 and 21 GHz and −3 dB bandwidth of 500 and 400 MHz, respectively, are synthesized. A Monte Carlo analysis shows that the proposed structure is fabrication-tolerant while filters based on milled coupling iris windows require post-process tuning. For experimental validation, a single reconfigurable transmission line structure able to implement both synthesized filters is demonstrated. In its transmission line configuration, it achieves a −20 dB return loss with a 0.1 dB insertion loss in the 15 to 22 GHz frequency range. In its filter configurations, obtained mounting the appropriate metallic posts, both filters achieve insertion loss as low as 0.7 dB and 0.73 dB, respectively, with return loss of better than −19 dB and −20 dB, respectively, without any post-process tuning. This topology is of particular interest for versatile and high performance microwave and millimeter-wave circuits and systems based on the AFSIW technological platform.

A differential vertical hybrid coupler and low capacitance RF pads for millimeter-wave applications in 28 nm CMOS FDSOI

Abstract: As millimeter-wave applications mostly rely on differential topologies, a differential design for quadrature hybrid coupler is also desired. The proposed Differential Vertical Hybrid Coupler (DVHC) concept is presented and dimensions are given for a 75 GHz operating frequency using 28 nm CMOS FDSOI technology. Simulated insertion loss is only 0.5 dB while return loss and isolation are close to 30 dB exhibiting very weak frequency dependence on all ports. Measurements on test structures confirm wideband operation and low insertion loss. Additionally, a flip-chip compatible RF pad with ultra-low parasitic capacitance is designed here and characterized (11 fF reported at 75 GHz).

Fabrication-Tolerant AFSIW Filters Based on Quadruplet Through-Hole Mounted Inductive Posts

Abstract: In this paper, air-filled substrate integrated waveguide (AFSIW) bandpass filters based on quadruplet through-hole mounted inductive posts are proposed and demonstrated. First, a comparison between the conventional inductive iris coupling and the inductive post coupling is introduced. Both geometries are compared in terms of performances and fabrication tolerance. A Monte Carlo analysis shows that printed circuit board (PCB) drilling process is more accurate than machining process. Then, a study on the internal coupling based on single inductive post is compared with its counterpart based on quadruplet inductive posts. For demonstration purposes, a fourth-order bandpass filter centered at 21 GHz with 1.4 % relative bandwidth is synthesized and fabricated. It achieves a −19 dB return loss with a −0.73 dB insertion loss. The calculated unloaded quality factor of the prototyped bandpass filter is 1594. This fabrication-tolerant topology is of high interest for future systems on substrate. The proposed low-cost and manufacturing tolerant filter structure is believed by the authors to contribute to the democratization of the millimetre-wave spectrum earth resource.

A Comparison of Beamforming Schemes for 5G mm-Wave Small Cell Transmitters

Abstract: The combination of Massive MIMO (M-MIMO) and small cells has been selected for the fifth generation (5G) of mobile telecommunication system. But large-scale antenna arrays and extreme densification brings an important power consumption which is not compliant with the energy saving needs. Early studies have excluded fully-digital transmitters due to their high power consumption and complexity. However, the benefits of hybrid beamforming systems may not be so obvious. This paper presents an overview of 5G requirements and prospective solutions. It focuses on the base station transmitter topologies for small cells and compare their power consumption and complexity. As hybrid beamforming is suitable for small arrays covering few users, fully-digital transmitters seems compliant with larger systems to reach 5G targets.

Air-Filled SIW Filters for K- to E-Band Substrate Integrated Systems

Abstract: In this paper, air-filled substrate integrated waveguide (AFSIW) bandpass filters based on inductive iris coupling are proposed for K- to E-band applications in substrate integrated circuits and systems. Three filters, operating in the K-band, Q-band and E-band are designed and experimentally demonstrated. First, the theory of this type of bandpass filters is detailed. Then, for demonstration purposes, three fourth-order AFSIW bandpass filters centered at 21 GHz, 38 GHz and 78 GHz with 1.4 %, 2.63 % and 5.23 % bandwidth respectively are synthesized and fabricated. The filters operating in the K-band, Q-band and E-band achieves a 20 dB, 17 dB and 10 dB return loss and a 0.7 dB, 0.55 dB and 0.91 dB insertion loss, respectively, without time-consuming post process tuning. The calculated unloaded quality factors are 1607 and 1065 respectively for the K-band and Q-band. This technology is of particular interest for the design of low cost extremely high frequency integrated systems on substrate.

Low group delay variation 3-10 GHz 65 nm CMOS stacked power amplifier with 18.1 dBm peak 1 dB compression output power

Abstract: A 3-10 GHz stacked power amplifier (PA) with low group delay variation and 18.1 dBm peak 1 dB compression output power (P1dB) in 65 nm CMOS bulk technology is presented. It is intended for ultra-wideband or multiband telecommunication, sensing, and instrumentation systems operating in the 3-10 GHz frequency range situated in the S, C, and X bands. Its design, based on stacked transistors allowing a supply voltage as high as 4 V to achieve a high 1 dB compression output power, is detailed. In the 3–10 GHz band, the proposed PA provides measured gain, P1dB, and maximum power added efficiency (PAEmax) of 12.65 ± 1.25 dB, 16 ± 2.1 dBm, and 20.15 ± 7.55%, respectively. In addition, in its frequency range of operation, this PA achieves an excellent measured group delay variation of ±21.55 ps. To the authors’ knowledge, this wideband PA offers the lowest group delay variation in this frequency range of operation.

Ultra-Compact Low-Loss Integrated Transformer-Based Ku-Band Quadrature Hybrid Coupler

Abstract: In this paper, an ultra-compact transformer-based integrated quadrature hybrid coupler is presented. Its design, taking advantage of the transformer distributed parasitic capacitances to minimize lumped capacitors, achieves low insertion loss and high compactness. For demonstration purposes, a prototype, operating at Ku-band and based on the 130 nm BiCMOS technology from STMicroelectronics, has been fabricated. Theoretical, simulated and experimental results are reported. The demonstrated integrated coupler occupies an area as small as 0.0014 mm2. In the 17.3 to 20.2 GHz frequency range (15.5% relative bandwidth) used for SATCOM applications, an insertion loss and a phase imbalance of better than 0.4 dB and 2° are experimentally obtained, respectively, with an amplitude imbalance of less than 1 dB.

Design of a Butler Matrix for Switched Beam Application

Abstract: A 4×4 Butler Matrix with a linear aperture coupled antenna array was designed. The design was aimed for a 2.45 GHz resonance frequency and was done on a FR-4 substrate in order to obtain four differents beams. Simulation were done with Advanced Design System and ANSYS HFSS softwares. For one antenna a 3.7 dB radiation magnitude was achieved at 2.45 GHz and a −32 dB reflexion coefficient according to HFSS simulation. Moreover, the Butler matrix leads to steering four steering beams.

Microwave component and associated manufacturing process

Abstract: This microwave component (10) comprises a waveguide (12) comprising an upper layer, a lower layer, and a central layer (18) intermediate between the upper layer and the lower layer, said layers defining a zone (19) of propagation of an electromagnetic wave, the propagation zone (19) extending along a propagation axis, and comprising a cavity (32) bounded by the upper layer, the lower layer, and, laterally, by two opposite lateral edges (36) of the central layer (18). The waveguide (12) comprises at least one dielectric strip (28) placed in the propagation zone (19), the dielectric strip (28) being defined in one of the upper layer and the lower layer or being placed in the cavity (32) away from the lateral edges (36) of the cavity (32).

Implementation of inductive posts in an siw structure and production of a generic filter

Abstract: The upper layer (14) comprises at least an upper hole (30) passing through it; the lower layer (16) comprises at least one lower hole (46) passing through it An electrically conductive wire (22) is received through the upper hole (30), the propagation area (20) and the lower hole (46), the conductive wire (22) being electrically connected to the electrically conductive surface (26) of the upper layer (14) and the electrically conductive surface (44) of the lower layer (16)

Fully Integrated Reconfigurable MASMOS Power Amplifier for LTE Applications

Abstract: In this paper, a fully integrated reconfigurable power amplifier (PA) intended for long-term evolution (LTE) applications is introduced. Its reconfigurable design provides versatility to comply with various applicative conditions. The proposed design is based on MASMOS transistor providing up to 32.7 dBm of saturated output power (PSAT) in LTE-band VII, while allowing a good tradeoff between linearity and power consumption. An analysis of the output combining transformer dimensioning is presented to optimize performances. Small signal and large signal post-layout results are reported for three operating modes: high performance (mode 1), low consumption (mode 2) and high linearity (mode 3). In its high linearity mode, providing the best tradeoff between output power and quiescent consumption, the PA achieves 31.6 dBm of 1-dB compression point (P1dB), at only 0.9 dB back-off from the PSAT. The PA is presently in fabrication. It is believed by the authors to be used in applications requiring high performance and adaptability to varying conditions, especially for the internet of things (IoT).

Microwave component having an asymmetric propagation chamber

Abstract: A microwave component (10) having an upper layer (14), a lower layer (16), and a core layer (18) defining a propagation zone (19) of an electromagnetic wave extending along a propagation axis (X-X), the propagation zone (19) comprising at least one symmetrical propagation chamber (28). The propagation zone (19) further comprises an asymmetrical propagation chamber (32) defined by the upper layer (14), the lower layer (16) and two spaced-apart lateral boundaries (34, 36) suitable for preventing the passage of an electromagnetic wave having a wavelength greater than or equal to a predetermined minimum wavelength, the lateral boundaries (34, 36) of the asymmetric chamber (32) being non-symmetrical in relation to any plane parallel to the plane of symmetry.