A 10-way power divider based on a transducer and a radial junction operating in the circular TM01 mode

This work presents a 10-way Ku-band power divider using a mode transducer and a radial junction connected by an overmoded circular waveguide operating in the TM 01 mode. The circular symmetry of this mode has been exploited to obtain a power divider with the rectangular output ports radially distributed along the broad wall of the waveguides in H-plane configuration. This topology provides the same amplitude and phase for all the output ports. At the same time, a compact profile has been obtained, introducing a simple manufacturing for the two components of the divider. The first component is a mode transducer converting the TE 10 mode in the rectangular waveguide to the TM 01 mode in the circular waveguide. It is based on a novel topology providing a very high purity in the mode conversion with an attenuation for the other propagating mode, the TE 11c , higher than 60 dB. The second component is a 10-way radial junction that must work under the excitation of the TM 01 , whose special features, since this mode is not the fundamental one of the circular waveguide, will be highlighted. The final design has been validated with an experimental prototype, proposing a manufacturing based on four simple parts. This has been the key to obtain an experimental prototype with specifications in the state-of-the-art. The measured efficiency is better than 96.5% in a 16.7% relative frequency bandwidth from 11 GHz to 13 GHz, with return losses better than 25 dB in the common port. The measured difference between the signals at the output ports of the prototype is ±0.3 dB for the amplitudes and ±0.45° for the phases. A comparison of the obtained results with another divider based on the TE 01 mode shows the potential of the presented design for becoming an alternative to the more extended TE 01 -based power dividersThis work was supported by the Spanish Government through the Agencia Estatal de Investigacion, Fondo Europeo de Desarrollo Regional (AEI/FEDER, UE), under Grant TEC2016-76070-C3-1/2-R (ADDMATE

Full-band oversized turnstile-based waveguide four-way power divider/combiner for high-power applications

Very high-power and high-efficiency microwave applications require waveguide structures to combine/divide the power from/to a variable number of high-power solid-state devices. In the literature, among the different waveguide configurations, those capable of providing the maximum output power show a limited relative bandwidth. To overcome this limitation, in this paper a full-band (40%) waveguide power divider/combiner specifically designed for high-power applications (up to several kW) is presented. The proposed structure uses an evolved turnstile junction with a standard rectangular waveguide common port, rotated 45°, with respect to its central axis, to divide/combine the signal to/from the four output/input rectangular ports. The inclusion of an oversized central cavity together with circular and rectangular waveguide impedance transformers at the common port allows the achievement of a full-band operation with excellent electrical performance, while maintaining a very simple and compact configuration. Only two layers of metal are required for the physical implementation of this structure in platelet configuration. A prototype has been designed covering the full Ka-band (26.5-40 GHz), showing an excellent measured performance with around 30 dB of return loss, 0.18 dB of insertion loss, and less than 1.5° of phase imbalance

Towards an Advanced Automotive Radar Front-end Based on Gap Waveguide Technology

This thesis presents the early works on dual circularly polarized array antenna based on gap waveguide, also microstrip-to-waveguide transitions for integration of automotive radar front-end. Being the most widely used radar antenna, PCB antenna suffers from dielectric loss and design flexibility. Next generation automotive radars demand sophisticated antenna systems with high efficiency, which makes waveguide antenna become a better candidate. Over the last few years, gap waveguide has shown advantages for implementation of complicated antenna systems. Ridge gap waveguides have been widely used in passive gap waveguide components design including slot arrays. In this regard, two transitions between ridge gap waveguides and microstrip lines are presented for the integration with gap waveguide antennas. The transitions are verified in both passive and active configuration. Another work on packaging techniques is presented for integration with inverted microstrip gap waveguide antennas.Systems utilizing individual linear polarization (LP) that lack polarimetric capabilities are not capable of measuring the full scattering matrix, thus losing information about the scenery. To develop a more advanced radar system with better detectability, dual circularly polarized gap waveguide slot arrays for polarimetric radar sensing are investigated. An 8 78 planar array using double grooved circular waveguide polarizer is presented. The polarizers are compact in size and have excellent polarization properties. Multi-layer design of the array antenna benefits from the gap waveguide technology and features better performance. The works presented in this thesis laid the foundation of future works regarding integration of the radar front end. More works on prototyping radar systems using gap waveguide technology will be presented in future publications

A 32-GHz solid-state power amplifier for deep space communications

A 1.5-W solid-state power amplifier (SSPA) has been demonstrated as part of an effort to develop and evaluate state-of-the-art transmitter and receiver components at 32 and 35 GHz for future deep space missions. Output power and efficiency measurements for a monolithic millimeter-wave integrated circuit (MMIC)-based SSPA are reported. Technical design details for the various modules and a thermal analysis are discussed, as well as future plans

Design of Tunable Beamforming Networks Using Metallic Ridge Gap Waveguide Technology

Wireless communication is a leap of development in the history of humanity. For the past 100 years, a considerable effort has been spent to develop better standards, and technologies for a higher speed wireless communication with high system capacity for different applications. This requires the design of a high-frequency, point-to-multipoint antenna array system to achieve the mentioned goals. In addition, the reconfigurability of this antenna system is essential to change the system characteristics to achieve acceptable performance in different situations. The main goal of this thesis is to design a reconfigurable beamforming network to work on the Ka-band for waveguide applications. Among different beamforming networks in the literature, the Butler matrix is chosen due to its higher efficiency and the smaller number of components required than other beamforming networks. The Butler matrix is designed using a dual-plane topology to avoid using crossovers. Ridge gap waveguide technology is chosen among different transmission lines to implement the Butler matrix for several reasons: It does not need dielectrics to operate, so its power handling capacity is defined by the gap height, and it has no dielectric losses. Its zero-field region represents the operating principle for some tunable devices introduced here and its contactless nature, which eases the assembly of waveguide parts at the millimeter-wave frequencies. The reconfigurability of the Butler matrix is implemented such that beamwidth, maximum gain, and beam direction may be all tuned for optimum system performance. To that end, several components are designed to achieve the required target, and strict requirements are placed on several components to achieve an acceptable cascaded-system performance. These components include a ridge gap waveguide 90o-hybrid working over a more than 30% bandwidth, which can provide several coupling levels ranging from 3 dB to 33 dB and a return loss and isolation better than 30 dB. Another component is a wideband reconfigurable power splitter that has a 40% bandwidth, a return loss better than 20 dB in the worst case and the ability to achieve all power splitting ratios including switching between the two guides. In addition, a wideband reconfigurable phase shifter is designed to have 33% bandwidth and phase shift tuning range from 0o to 200o. Two coaxial-to-ridge gap waveguide transitions are designed to work over a more than 100% bandwidth to facilitate testing different ridge gap waveguide components. Analysis of the asymmetric double ridge waveguide is introduced where its impedance is deduced and may be used to design a single to double ridge waveguide transition useful for the dual-plane Butler matrix introduced here. In addition, this concept is used to develop a wideband unequal power divider in the single ridge waveguide technology. At the end, the whole system is assembled to show its performance in different tuning states. The ability of the system to produce radiation patterns of different characteristics is demonstrated. The presented Butler matrix design is a promising beamforming network for several applications like radar, base stations for mobile communications, and satellite applications

Miniaturization Techniques of Substrate Integrated Waveguide Based on Multilayered Printed Circuit Board Platform

RESUMÉ Le guide d'ondes intégrées au substrat (GIS) est une structure à ondes guidées qui présente des avantages avec un facteur de qualité Q élevé et une excellente isolation ligne à ligne. La technique GIS a été largement utilisé dans la construction de composants passifs, tels que coupleurs, diviseurs, filtres, et déphaseurs. Certains dispositifs actifs ont également été développés avec facteur Q élevé et résonateurs en technologie GIS. En comparant à d'autres types de lignes de transmission planaire, le facteur de qualité Q important du GIS est une embouchure pour son intégration avec d'autres circuits classiques. Les techniques de miniaturisation du SIW sont donc devenues une urgence. Le travail dans cette thèse commence par l'examen et la discussion des techniques de miniaturisation existantes pour GIS, y compris les (ridge substrate integrated waveguide, RSIW), intégrés sur substrat à demi-mode (HMSIW) et les (folded substrata integrated waveguide, FSIW). L'impédance et la constante de propagation des lignes basées sur ces techniques de miniaturisation sont calculées en utilisant la méthode de résonance transversale (transverse resonant method, CRT). Bien que ces paramètres puissent être obtenus par des méthodes de simulation EM, un calcul rapide sera utile pour l’optimisation de la conception en utilisant l'analyse paramétrique. Une préoccupation particulière est axée sur la relation entre la constant d’atténuation et les paramètres géométriques. Les dimensions optimisées de chaque GIS miniaturisés sont proposés en se basant sur l'analyse paramétrique. Les paramètres de transmission de ces lignes de SIW miniaturisés peuvent être extraire en utilisant la méthode à double ligne. Sauf HMSIW, toutes les autres techniques de miniaturisation mentionnées ci-dessus pour la mise en œuvre de la plateforme multicouche. Parmi les techniques de fabrication diverses qui sont en mesure de fournir des substrats multicouches, le circuit imprimé multicouche est utilisé dans la conception des circuits rapportés dans cette thèse.---------- ABSTRACT Substrate integrated waveguide (SIW) is a guided-wave structure that enjoys the benefits of a high Q-factor and an excellent line-to-line isolation. SIW technique has been widely used in building passive components, such as couplers, dividers, filters, and phase shifters. Some active devices have also been developed with high Q-factor SIW resonators. Comparing to other types of planar transmission lines, the big form factor of SIW is a bottleneck for its integration with other conventional integrated circuits. Miniaturization techniques for SIW therefore become very urgent. The work in this dissertation starts with the review and discussion of existing miniaturization techniques for SIW, including ridge substrate integrated waveguide (RSIW), half-mode substrate integrated waveguide (HMSIW) and folded substrata integrated waveguide (FSIW). The impedance and propagation constant of the transmission lines based on these miniaturization techniques are calculated using transverse resonant method (TRM). Although these parameters can be extracted from full wave EM simulations, a fast computation be helpful in design optimization by using parametric analysis. One particular concern focuses on the relationship between attenuation constant and geometric parameters. Optimized dimensions of each miniaturized SIW are suggested based on the parametric analysis. The transmission line parameters of these miniaturized SIW transmission lines can be extracted using dual-line method. Except HMSIW, all other miniaturized techniques mentioned above need multilayer platform for implementation. Among various fabrication techniques which are able to provide multilayered substrate, multilayer printed circuit board is used in the design of the circuits reported in this dissertation. It is believed that the advantages of SIW circuit are important in millimeter wave applications, although the design might limit the operating frequency. Specifically, Rogers substrate R6002 is used in all our designs for proving the concepts investigated in this work. One principal step for using the SIW technology is to develop high-performance transitions and interconnects between substrate integrated circuits (SICs) and other types of transmission lines or circuits embedded in or surface mounted on the multilayer substrates. In this work, a novel transition between a microstrip line and an SIW in a multilayer substrate design environment is presented