With the rapid expansion of wireless communication services, ultra-miniature, low cost RF microsystems operating at higher carrier frequencies (e.g. 5-6 GHz) are in demand for various applications. Such applications include networked wireless sensor nodes and wireless local area data networks (WLANs). Integrated microstrip antennas coupled directly to the RF electronics, offer potential advantages of low cost, reduced parasitics, simplified assembly and design flexibility compared to systems based on discrete antennas. However, the size of such antennas is governed by physical laws, and cannot be arbitrarily reduced. The critical patch antenna dimension at resonance needs to be ~ λ_g/2 (where λ_g is the guided wavelength given by λ_g=λ₀/√(𝜖_r) . Several methods are available to reduce the physical size of the antenna to enable on-chip integration. A high dielectric constant substrate reduces the guided wavelength. Grounding one edge of the microstrip patch enables the resonant antenna length to be further reduced to ~ λ_g/4. However, these techniques result in degraded antenna efficiency and bandwidth. Nonetheless, such antennas still have potential for use in low power/short range applications. In this work, "electrically small" (small with respect to λ₀) square-shaped microstrip patch antennas, grounded on one edge by shorting posts, have been investigated. The antenna input impedance depends on the feed position; by adjusting the feed point, the antenna can be tuned to match a 50 Ω or other system impedance. The antennas were designed on a GaAs substrate, with a high dielectric constant of 12.9. The size of the patch antenna is further reduced by utilizing shorted through substrate vias along one edge. The size of the antenna is about 4.2mm × 4.2mm, which is ~1/13 of λ₀ at ~5.6GHz. The antennas are practical for integration on chip. Due to the size reduction, the simulated peak gain of the antenna is only −10.2 dB (~3.2% radiation efficiency). However, this may be acceptable for short-range wireless communications and distributed sensor network applications. Based on the above approach, integrated GaAs "chip-scale" antennas with matching power amplifiers have been designed and fabricated. Class A tuned MESFET power amplifiers (PAs) were designed with outputs directly matched to the antenna feed point. The antenna is fabricated on the backside of the chip through backside patterning; the PA feeds the antenna through a backside via. The structure is then mounted such that the antenna faces up, and is compatible with flip-chip technology. The measurement of a 50 Ω passive (no PA) antenna indicates a gain of -12.7dB on boresight at 5.64 GHz, consistent with the antenna size reduction. The measurement of one active antenna (50 Ω system) shows a gain of -4.3dB on boresight at 5.80 GHz. The other version of active antenna (22.5 Ω system) shows a gain of −2.9 dBi on boresight at 5.725 GHz. The active circuitry (PA) contributes an average of ~9 dB gain in the active antenna, reasonable close to the designed PA gain of 12.7dB. The feasibility of direct integration of a PA with an on-chip antenna in a commercial GaAs process at RF frequencies was successfully demonstrated. / Master of Science

This paper proposes two innovative designs for the broadband and high-gain circularly polarized operation, a corner-truncated inverted -L patch antenna and a cylindrical-probe-fed circularly polarized patch antenna using a single probe feed. Next, the broad circularly polarized printed spiral strip antenna for 5 GHz WLAN operation is studied; we also proporse a compact dual-band circularly polarized antenna for GPS/ETC operation on vechicles. In addition, an experimental study of the nearly square circularly polarized microstrip antenna with a rectangular ground plane is presented. The CP antennas are greatly affected by the different side lengths of the rectangular ground plane. To compensate for this effect, the aspect ratio of the nearly square radiating patch should be increased with the increasing aspect ratio of the rectangular ground plane.

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The objectives of this research work are to investigate, design and implement active integrated antennas comprising active devices connected directly to the patch radiators, for various applications in high efficiency RF front-ends, integrated oscillator antennas, design and optimization of harmonic suppression antennas using a genetic algorithm (GA). A computer-aided design approach to obtain a class F operation to optimizing the optimal fundamental load impedance and designing the input matching circuits for an active integrated antenna of the transmitting type is proposed and a case study of a design for 1.6 GHz is used to confirm the design principle. A study of active integrated oscillator antennas with a series feed back using a pseudomorphic high electronmobility transistor (PHEMT) confirms the design procedure in simulation and measurement for the oscillator circuit connected directly to the active antenna. Subsequently, another design of active oscillator antenna using bipolar junction transistor (BJT) improves the phase noise of the oscillation and in addition to achieve amplitude shift keying (ASK) and amplitude modulation (AM) modulation using the proposed design circuit. Moreover, the possibility of using a sensor patch technique to find the power accepted by the antenna at harmonic frequencies is studied. A novel numerical solution, for designing and optimizing active patch antennas for harmonic suppression using GA in collaboration with numerical electromagnetic computation (NEC), is presented. A new FORTRAN program is developed and used for adaptively meshing any planar antenna structure in terms of wire grid surface structures. The program is subsequently implemented in harmonic suppression antenna design and optimization using GA. The simulation and measurement results for several surface structures show a good agreement.

yes / The objectives of this research work are to investigate, design and implement active integrated antennas comprising active devices connected directly to the patch radiators, for various applications in high efficiency RF front-ends, integrated oscillator antennas, design and optimization of harmonic suppression antennas using a genetic algorithm (GA). A computer-aided design approach to obtain a class F operation to optimizing the optimal fundamental load impedance and designing the input matching circuits for an active integrated antenna of the transmitting type is proposed and a case study of a design for 1.6 GHz is used to confirm the design principle. A study of active integrated oscillator antennas with a series feed back using a pseudomorphic high electronmobility transistor (PHEMT) confirms the design procedure in simulation and measurement for the oscillator circuit connected directly to the active antenna. Subsequently, another design of active oscillator antenna using bipolar junction transistor (BJT) improves the phase noise of the oscillation and in addition to achieve amplitude shift keying (ASK) and amplitude modulation (AM) modulation using the proposed design circuit. Moreover, the possibility of using a sensor patch technique to find the power accepted by the antenna at harmonic frequencies is studied. A novel numerical solution, for designing and optimizing active patch antennas for harmonic suppression using GA in collaboration with numerical electromagnetic computation (NEC), is presented. A new FORTRAN program is developed and used for adaptively meshing any planar antenna structure in terms of wire grid surface structures. The program is subsequently implemented in harmonic suppression antenna design and optimization using GA. The simulation and measurement results for several surface structures show a good agreement.

Avec l’explosion du trafic de données mobiles, des débits supérieurs au Gb/s deviennent nécessaires pour l’utilisateur. Ainsi, le réseau de communication est en cour d’amélioration afin de promouvoir le déploiement de la 5G, notamment grâce au développement et à l’installation de systèmes sans fil d’onde millimétrique (mmW) à 10 Gb/s. Néanmoins, pour délivrer de tels débits, les liens fronthaul/backhaul sans fil connectés au cœur de réseau devront supporter des flux de données supérieurs à 40 Gb/s. Cet enjeu suscite un intérêt croissant pour les fréquences sub-mmW et THz (0.1 THz – 1 THz) autour desquelles des bandes passantes (BPs) de 100 GHz sont accessibles. Il serait en effet possible d’atteindre un débit de 100 Gb/s, tout en utilisant des formats de modulation simples et ainsi réduire la consommation d’énergie du système. Visant le marché de masse des applications haut-débits, la technologie Photonique sur Silicium est particulièrement attractive pour générer des BPs naturellement larges et pour sa capacité à forts niveaux d’intégration et faible cout de fabrication. Dans cette thèse, une technologie Photonique sur Silicium industrielle a donc été évaluée durant le développement d’un émetteur intégré THz fonctionnant sur la base d’une photodiode et pouvant délivrer 100 Gb/s. Le développement d’une antenne THz faible cout et compacte est également un aspect majeur de cette thèse afin de permettre la transmission point-à-point du signal THz. En effet, une antenne intégrée sur substrat organique faible cout et à faibles pertes et une lentille fabriquée par impression 3D ont été développées afin d’évaluer ces technologies de prototypage industriel au-delà de 200 GHz. / With the booming of mobile data traffic, the need for higher data-rates is clearly felt. To cope with this strong demand and support the 5G roll-out, the capacity of the mobile communication network is being improved every day with many solutions, among which the development and installation of millimeterwave (mmW) wireless systems operating at up to 10 Gb/s. However, in order to deliver such high speeds to the user, the fronthaul/backhaul network sending data back to the core network would require above 40 Gb/s data-rate wireless links. This challenge generates a growing interest for sub-mmW and THz frequencies (0.1 THz – 1 THz) at which up-to 100 GHz bandwidth (BW) is accessible. In such BW, it would be possible to achieve up to 100 Gb/s data-rates while using simple modulation schemes to reduce the wireless system’s power consumption. Targeting mass-market high data-rates applications, Silicon Photonics technology seems very promising as it benefits from wide intrinsic BW and powerefficient components, as well as high integration levels and low manufacturing costs. In this context, a main aspect of this PhD project is the evaluation of an industrial Silicon Photonics technology for the development of a THz system-on-chip transmitter capable of reaching up to 100 Gb/s using a photodiode. Since THz antennas are also a hot topic for THz point-to-point transmission, a second aspect of this PhD study is the design of a low-cost and compact THz antenna-system. Hence, a planar antenna using low-loss organic packaging technology and a 3D-printed plastic lens were developed in order to assess those industrial prototyping techniques above 200 GHz.