Search

This letter presents an ultra-wideband crossover based on metallic-nanowire-filled membrane (MnM) from dc to 110 GHz. Two designs are proposed with reduced insertion loss and high isolation. Design Type 1 presents a 1.2 dB insertion loss and 19 dB isolation up to 80 GHz, with a phase imbalance of 14° at 80 GHz. This important phase imbalance is due to CPW that passes under the top microstrip (MS) line. To improve the device, a CPW was used in both paths. The improved design Type 2 shows a 1.5 dB insertion loss, 0.2 dB insertion loss imbalance, and 3.3° phase imbalance at 110 GHz. The latter presents a measured isolation of 38 dB up to 70 GHz and a simulated isolation better than 30 dB up to 110 GHz.

A switched‐line substrate integrated waveguide 1‐bit phase shifter is designed and measured at 28 GHz. Reconfigurability is achieved through a set of floating metallized vias whose connection to the waveguide top and bottom layers can be controlled using PIN diodes. The reconfigurable vias are used to dynamically create alternative paths having different phase delays. A three‐metal layer printed circuit board stack‐up is employed to fully integrate the diode biasing network and to ease the routing of the bias signal. The high integration of the proposed configuration makes it well suited for the implementation of reconfigurable Butler matrices. The phase shift offset between the two states of this digital 1‐bit phase shifter equals 262° at 28 GHz, leading to a measured figure of merit of 161°/dB, and input 1‐dB compression point over 20 dBm. The total area is 13.72 × 10.9 mm without feeding lines and bias.

In this paper, the design of a 77.3 GHz Standing-Wave oscillator (SWO) is presented. The proposed SWO relies on the distribution of varactors along an asymmetrical slow-wave coplanar stripline, which enables the improvement of the quality factor of the tunable resonator, resulting in superior performance in terms of phase noise and DC-to-RF efficiency. The design methodology, based on the use of analytical models and abaci, is presented in detail and applied to a design in a 55-nm CMOS technology. With a core consumption of 15.1 mW, the proposed SWO operates from 76.09 GHz to 78.60 GHz and presents a phase noise of −115.1 dBc/Hz at 10 MHz offset, leading to a Figure of Merit (FOM) of −181 dBc/Hz. The DC-to-RF efficiency obtained is 3.1%.

This paper presents an innovative Through-Load element aimed at characterization applications at mm-wave frequencies. The proposed structure can behave as a Through connection or as a 50- $\Omega $ load depending on a DC control voltage. Among other potential applications, this system can be used to implement a transfer switch or an attenuator. A demonstrator was fabricated and measured in the STM 55-nm BiCMOS technology. Over a wide bandwidth, from 55 GHz up to 170 GHz, experimental measurements demonstrate a maximum 1.6-dB of insertion loss when behaving as a Through connection and a minimum 14-dB of insertion loss when behaving as a 50- $\Omega $ load. In both cases, the return loss is better than 10 dB. The insertion loss at 90 GHz is 0.6 dB for the Through connection and 20 dB for the 50- $\Omega $ load connection.

ORAL session EuMIC03 Advanced Microwave Components; International audience; This paper presents a design perspective of 2 nd order patch-like grounded Complementary-Split-Ring-Resonator (CSRR) filter on BiCMOS 55-nm technology at 50 GHz. The advantage of using CSRR topology combined with grounded via allows a great reduction of the overall size to \boldsymbol{\lambda/7\times\lambda/13}\ \mathbf{mm}^{2} . General coupling matrix representation along with extracted external quality factor and resonators' pair coupling is conducted. The measured results show an insertion loss of 5 dB with a return loss better than 11 dB in the passband. The achieved fractional bandwidth is 23%.

The design of a compact substrate integrated waveguide (SIW) cavity-backed circular-polarized antenna using a slow wave structure is proposed in PCB technology. Based on a multilayer substrate, this topology includes internal metallized blind via holes connected to the bottom conductive plane, inducing the physical separation of electric and magnetic fields in the SIW cavity. Hence, a slow wave effect is obtained, allowing a 47% reduction of the antenna cavity in comparison with its classic SIW antenna counterpart. Moreover, by asymmetrically inserting an inductive via into the patch region, a degenerated mode allows both a circular polarization and an enlargement of impedance bandwidth. Measurements and simulations are in good agreement in terms of radiation pattern and circular polarization with a return loss of 15 dB and a gain of 4.8 dBic.

International audience; In this letter, 3-D transformers based on transmission lines (TLs) working at mm-wave frequencies are presented. They were realized in a low-cost technology based on metallic-filled nanoporous membranes. Several transformers were designed and measured with different numbers of turns, from 1 to 6 turns. They exhibit working frequencies from 14.5 up to 110 GHz. The 1-dB bandwidth (BW) of the realized transformers is better than 12 GHz, and the insertion loss (IL) is between 1.1 and 1.6 dB, thus demonstrating a high efficiency at mm-waves. Transformers could be further improved by better optimizing the TLs and their return current path, which is a key parameter to be considered, given the distributed nature of the proposed transformers.

This article introduces a description of the slow wave effect based on the analysis of spatial field separation. Considering an ideal parallel-plate framework, approximate analytical expressions are derived for the slow wave factor (SWF), as well as dielectric attenuation. In particular, it is shown that the SWF can be related to the spatial distribution of both electric and magnetic fields. It is also demonstrated that the dielectric attenuation increases by the same factor as the velocity reduces. The derived principles are applied to a study case consisting of a parallel-plate waveguide partially filled with vertically grown metallic nanowires.

MEMS-based phase shifters show the best performance in terms of figure of merit, but their footprints are usually large and it is difficult to achieve several bits. This paper demonstrates a miniaturized phase shifter based on slow-wave CPW and MEMS that occupy 0.47 mm2. A total phase shift of 152° was obtained with a maximum insertion loss of 3 dB, resulting in a figure of merit of 50°/dB at 60 GHz. The 3-bit device showed an insertion loss variation of 1.3 dB and return loss better than 13 dB. The pull-in and pull-out voltages were measured to be 17 V and 10 V, respectively. The presented device is well suited for mm-wave phased array applications. Thanks to the proposed concept, more bits could be easily achieved and much higher frequencies could be addressed.

In this paper, the patch concept is applied to the design of millimeter-wave band-pass filters in BiCMOS 55 nm technology. The operation frequencies are 120 GHz and 200 GHz, respectively. A via- and slot-based approach makes filters very compact, albeit patch-based, through a multi-mode approach. At 200 GHz, the side of the patch is only 194 μm long, or about a quarter wavelength, compared to half a wavelength for a conventional patch. The dependence of performance on the thickness of the Back-End-Of-Line is studied, and the design method is detailed. The performance is very good, with for example a filter operating at 200 GHz with a relative bandwidth of 23% and insertion loss of 3 dB. Finally, the prospect of using a thicker Back-End-Of-Line, offered as an option in 55-nm BiCMOS technology, makes it possible to show that even better performance can be achieved, with insertion loss below 3 dB.

International audience; The design and experimental results of millimeter-wave bandpass filters (BPFs) implemented in 55-nm BiCMOS technology and operating around 120 GHz are presented in this article. Slightly modified coupled line filters' structures are used in the designs. It allows generating the transmission zero at the upper stopband, leading to the selectivity of enhanced filters. The coupled line structure is implemented in two technologies, microstrip coupled lines and coupled slow-wave (SW) coplanar waveguides (CS-CPWs). The latter shows more design flexibility, allowing to reach a better filtering performance than the microstrip filters, i.e., better in-band flatness and higher selectivity. Good agreement is achieved between simulation, modeling, and measurement results. Also, the overall length of the filter based on CS-CPWs is smaller as compared to the filters based on the microstrip lines, thanks to the SW propagation.

The study presented in this article concerns germanium telluride (GeTe) phase-change material-based switches, actuated via direct heating and arranged through two configurations: series or shunt. It is concluded that direct heating provides a performing solution for GeTe amorphization, preventing heater aging. The two configurations are compared in terms of RF performance, power handling, and linearity. Some design rules are derived from empirical data, consolidated with thermal simulations. In either configuration, a large, thick, and short GeTe switch geometry is preferable. Higher isolation can be obtained in shunt configuration, while lower insertion loss can be reached in a series configuration. The Figure-of-Merit, as cutoff frequency, is 11 and 21 THz for shunt and series configurations, respectively. In terms of power handling, for amorphous GeTe, results confirm the existence of a threshold voltage leading to better handling for longer switches in both configurations. For crystalline GeTe, design rules that link the maximum current through the switch before failure to the material geometry are derived for the very first time. It is shown that current is proportional to the GeTe switch width, to the square root of its thickness, and inversely proportional to its length. The shunt configuration presented here holds 31 dBm at ON-state and more than 35 dBm at OFF-state while the series configuration holds 27 dBm at ON-state and 32 dBm at OFF-state. For power handling, a balance exists between series and shunt configurations with a ratio of 4 in the crystalline phase and of 0.25 in the amorphous phase.