Millimeter and Sub-Millimeter Wave Integrated Active Frequency Down-Converters

In recent years, the increasing amount of data transmission, the need for automotive radars, and standoff imaging for security applications are the main factors that accelerate research in the millimeter and sub-millimeter wave frequency ranges. The semiconductor industries have continuously developed their processes, which have opened up opportunities for manufacturing monolithically integrated circuits up to a few hundred GHz, based on transistor technologies. In this thesis, a 100 nm GaAs mHEMT technology, a 250 nm InP DHBT technology, and a 130 nm SiGe BiCMOS technology, which show a typical ft / fmax of 200/300 GHz, 375/650 GHz, and 250/400 GHz, respectively, are verified for analog circuit design. In the above mentioned applications, the frequency mixer is one of the most important components. Consequently, a study of millimeter/submillimeter wave mixers is important for the choice of technology and topology. Aiming for either the next generation of high-speed communication or standoff imaging applications, different mixer topologies are studied, designed and fabricated as candidates for further integration in receivers. The presented mixer topologies include the self-oscillating mixer, the resistive FET mixer, the Gilbert mixer, and the transconductance mixer. All these topologies have been realized in given technologies, and cover the frequencies around ~145 GHz, ~220 GHz, and ~340 GHz. The designed 340 GHz Gilbert mixer with IF buffer amplifier and on-chip patch array antenna demonstrated the first fully integrated receiver in HBT technology at such high frequencies as well as a reasonable noise figure of 17 dB. A novel 110~170 GHz transconductance mixer is characterized in ×1, ×2, ×3, and ×4 harmonic mixing modes, which allows for flexibility in the overall system design. Apart from the mixer designs, a transceiver, which operates as an amplifier for transmitting and simultaneously as a down-converting mixer for receiving, is designed for the frequency range of 110~170 GHz, aiming for sub-cm resolution in multipixel standoff imaging systems. It is successfully demonstrated in a FMCW radar setup for distance measurements

0.42 THz Transmitter with Dielectric Resonator Array Antenna

Off chip antennas do not occupy the expensive die area, as there is no limitation on their building material, and can be built in any size and shape to match the system requirements, which are all in contrast to on-chip antenna solutions. However, integration of off-chip antennas with Monolithic-Microwave-Integrated Chips (MMIC) and designing a low loss signal transmission from the signal source inside the MMIC to the antenna module is a major challenge and trade off. High resistivity silicon (HRS), is a low cost and extremely low loss material at sub-THz. It has become a prevailing material in fabrication of passive components for THz applications. This work makes use of HRS to build an off-chip Dielectric Resonator Antenna Array Module (DRAAM) to realize a highly efficient transmitter at 420 GHz. This work proposes novel techniques and solutions for design and integration of DRRAM with MMIC as the signal source. A proposed scalable 4×4 antenna structure aligns DRRAM on top of MMIC within 2 μm accuracy through an effortless assembly procedure. DRAAM shows 15.8 dB broadside gain and 0.85 efficiency. DRAs in the DRAAM are differentially excited through aperture coupling. Differential excitation not only inherently provides a mechanism to deliver more power to the antenna, it also removes the additional loss of extra balluns when outputs are differential inside MMIC. In addition, this work proposes a technique to double the radiation power from each DRA. Same radiating mode at 0.42 THz inside every DRA is excited through two separate differential sources. This approach provides an almost loss-less power combining mechanism inside DRA. Two 140_GHz oscillators followed by triplers drive each DRA in the demonstrated 4×4 antenna array. Each oscillator generates 7.2 dBm output power at 140 GHz with -83 dBc/Hz phase noise at 100 KHz and consumes 25 mW of power. An oscillator is followed by a tripler that generates -8 dBm output power at 420 GHz. Oscillator and tripler circuits use a smart layer stack up arrangement for their passive elements where the top metal layer of the die is grounded to comply with the planned integration arrangement. This work shows a novel circuit topology for exciting the antenna element which creates the feed element part of the tuned load for the tripler circuit, therefore eliminates the loss of the transition component, and maximizes the output power delivered to the antenna. The final structure is composed of 32 injection locked oscillators and drives a 4×4 DRAAM achieves 22.8 dBm EIRP

Silicon-Based Terahertz Circuits and Systems

The Terahertz frequency range, often referred to as the `Terahertz' gap, lies wedged between microwave at the lower end and infrared at the higher end of the spectrum, occupying frequencies between 0.3-3.0 THz. For a long time, applications in THz frequencies had been limited to astronomy and chemical sciences, but with advancement in THz technology in recent years, it has shown great promise in a wide range of applications ranging from disease diagnostics, non-invasive early skin cancer detection, label-free DNA sequencing to security screening for concealed weapons and contraband detection, global environmental monitoring, nondestructive quality control and ultra-fast wireless communication. Up until recently, the terahertz frequency range has been mostly addressed by high mobility compound III-V processes, expensive nonlinear optics, or cryogenically cooled quantum cascade lasers. A low cost, room temperature alternative can enable the development of such a wide array of applications, not currently accessible due to cost and size limitations. In this thesis, we will discuss our approach towards development of integrated terahertz technology in silicon-based processes. In the spirit of academic research, we will address frequencies close to 0.3 THz as 'Terahertz'. In this thesis, we address both fronts of integrated THz systems in silicon: THz power generation, radiation and transmitter systems, and THz signal detection and receiver systems. THz power generation in silicon-based integrated circuit technology is challenging due to lower carrier mobility, lower cut-o frequencies compared to compound III-V processes, lower breakdown voltages and lossy passives. Radiation from silicon chip is also challenging due to lossy substrates and high dielectric constant of silicon. In this work, we propose novel ways of combining circuit and electromagnetic techniques in a holistic design approach, which can overcome limitations of conventional block-by-block or partitioned design methodology, in order to generate high-frequency signals above the classical definition of cut-off frequencies (ƒt/ƒmax). We demonstrate this design philosophy in an active electromagnetic structure, which we call Distributed Active Radiator. It is inspired by an Inverse Maxwellian approach, where instead of using classical circuit and electromagnetic blocks to generate and radiate THz frequencies, we formulate surface (metal) currents in silicon chip for a desired THz field prole and develop active means of controlling different harmonic currents to perform signal generation, frequency multiplication, radiation and lossless filtering, simultaneously in a compact footprint. By removing the articial boundaries between circuits, electromagnetics and antenna, we open ourselves to a broader design space. This enabled us to demonstrate the rst 1 mW Eective-isotropic-radiated-power(EIRP) THz (0.29 THz) source in CMOS with total radiated power being three orders of magnitude more than previously demonstrated. We also proposed a near-field synchronization mechanism, which is a scalable method of realizing large arrays of synchronized autonomous radiating sources in silicon. We also demonstrate the first THz CMOS array with digitally controlled beam-scanning in 2D space with radiated output EIRP of nearly 10 mW at 0.28 THz. On the receiver side, we use a similar electronics and electromagnetics co-design approach to realize a 4x4 pixel integrated silicon Terahertz camera demonstrating to the best of our knowledge, the most sensitive silicon THz detector array without using post-processing, silicon lens or high-resistivity substrate options (NEP &lt; 10 pW &#8730; Hz at 0.26 THz). We put the 16 pixel silicon THz camera together with the CMOS DAR THz power generation arrays and demonstrated, for the first time, an all silicon THz imaging system with a CMOS source.</p

RF-MEMS Switch Module in a 0.25 µm SiGe:C BiCMOS Process

Drahtlose Kommunikationstechnologien im Frequenzbereich bis 6 GHz wurden in der Vergangenheit in Bezug auf Leistungsfaehigkeit und Frequenzbereich kontinuierlich verbessert. Aufgrund der Skalierung nach dem Mooreschen Gesetz koennen heutzutage mm-Wellen Schaltkreise in CMOS-Technologien hergestellt werden. Durch die Einfuehrung von SiGe zur Realisierung einer leistungsfaehigen BiCMOS-Technologie wurde ebenfalls eine Verbesserung der Frequenzeigenschaften und Ausgangsleistungen erreicht, wodurch aktive CMOS- oder BiCMOS-Bauelemente vergleichbare Leistungsparameter zu III-V Technologien bei geringeren Kosten bereitstellen koennen. Bedingt durch das niederohmige Silizium-Substrat der BiCMOS-Technologie weisen vor allem passive Komponenten hoehere Verluste auf und weder III-V- noch BiCMOS-Technologien bieten hochlineare Schaltkomponenten mit geringen Verlusten und geringen Leistungsaufnahmen im mm-Wellen Bereich. RF-MEMS Schalter sind bekannt fuer ihre ausgezeichneten HF-Eigenschaften. Die Leistungsaufnahme von elektrostatisch angetriebenen RF-MEMS Schaltern ist vernachlaessigbar und es koennen im Vergleich zu halbleiter-basierten Schaltern hoehere Leistungen verarbeitet werden. Nichtsdestotrotz wurden RF-MEMS Schalter hauptsaechlich als eigenstaendige Komponenten entwickelt. Zur Systemintegration wird meist ein System-in-Package (SiP) Ansatz angewandt, der fuer niedrige Frequenzen geeignet ist, aber bei mm-Wellenanwendungen durch parasitaere Verluste an seine Grenzen stoesst. In dieser Arbeit wird ein in eine BiCMOS-Technologie integrierter RF-MEMS Schalter fuer mm-Wellen Anwendungen gezeigt. Das Design, die Integration und die experimentellen Ergebnisse sowie verschiedene Packaging-Konzepte werden beschrieben Zur Bereitstellung der hohen Auslenkungs-Spannungen wurde eine Ladungspumpe auf dem Chip integriert. Zum Schluss werden verschiedene, rekonfigurierbare mm-Wellen Schaltkreise zur Demonstration der Leistungsfaehigkeit des Schalters gezeigt.Wireless communication technologies have continuously advanced for both performance and frequency aspects, mainly for the frequencies up to 6 GHz. The results of Moore’s law now also give the opportunity to design mm-wave circuits using advanced CMOS technologies. The introduction of SiGe into CMOS, providing high performance BiCMOS, has also enhanced both the frequency and the power performance figures. The current situation is that the active devices of both CMOS and BiCMOS technologies can provide performance figures competitive with III-V technologies while having still the advantage of low cost. However, similar competition cannot be pronounced for the passive components considering the low-resistive substrates of BiCMOS technologies. Moreover, both III-V and BiCMOS technologies have the lack of low-loss and low-power consumption, as well as highly linear switching and tuning components at mm-wave frequencies. RF-MEMS switch technologies have been well-known with excellent RF- performance figures. The power consumption of electrostatic RF-MEMS switches is negligible and they can handle higher power levels compared to their semiconductor counterparts. However, RF-MEMS switches have been mostly demonstrated as standalone processes and have started to be used as commercial off-the-shelf (COTS) devices recently. The full system integration is typically done by a System-in-Package (SiP) approach. Although SiP is suitable for lower frequencies, the packaging parasitics limit the use of this approach for the mm-wave frequencies. In this thesis, a fully BiCMOS embedded RF-MEMS switch for mm-wave applications is proposed. The design, the implementation and the experimental results of the switch are provided. The developed RF-MEMS switch is packaged using different packaging approaches. To actuate the RF-MEMS switch, an on-chip high voltage generation circuit is designed and characterized. The robustness and the reliability performance of the switch are also presented. Finally, the developed RF-MEMS switch is successfully demonstrated in re-configurable mm-wave circuits