A high performance ultra-wideband low cost SMA-to-GCPW transition

This letter presents a novel low cost through-the-wall SMA connector and the transition structures from the SMA to a grounded coplanar waveguide (GCPW). The SMA connector has two short metal legs extended from the outer conductor used to reduce the discontinuity of the transition. The parameters of the GCPW are designed to match the geometry of the coaxial. A matching stub is introduced in the center conductor line to further improve the performance of the transition. A prototype device is developed and measured. The measurement results show the return loss of the proposed transition is better than 20dB up to 26.5GHz

PERANCANGAN POWER DIVIDER ULTRA WIDEBAND BERBASIS SUBSTRATE INTEGRATED WAVEGUIDE (SIW) UNTUK APLIKASI RADAR PENETRASI

Power divider telah banyak digunakan dalam perancangan sistem gelombang mikro dan gelombang milimeter. Power divider konvensional yang berbentuk waveguide memiliki rugi-rugi yang sangat rendah namun dimensinya masih tergolong yang besar dan non-planar sehingga sulit untuk diintegrasikan pada rangkaian gelombang mikro. Disisi lain, penerapan teknologi mikrostrip pada power divider lebih memungkinkan karena bentuknya yang compact dan low-cost namun rugi-rugi yang dihasilkan masih relatif tinggi. Sebuah teknologi bernama Substrate Integrated Waveguide (SIW) dipandang mampu untuk menyelesaikan masalah tersebut karena strukturnya yang compact, low-cost, planar serta rugi-rugi yang rendah dibanding mikrostrip. Pada penelitian ini, prototipe power divider berbasis SIW telah selesai dirancang, disimulasikan dan difabrikasi untuk memenuhi parameter-parameter yang ditentukan untuk memenuhi spesifikasi yang mengacu pada radar penetrasi. Optimasi juga telah dilakukan pada power divider untuk memperbaiki nilai return loss (S11), insertion loss (S21 dan S31) serta memperkecil nilai ripple pass-band pada power divider. Disamping itu, karakteristik dari SIW sebagai struktur dasar power divider juga turut diinvestigasi seperti pengaruh diameter via SIW, tebal substrat, tipe transisi dan mode propagasi. Power divider SIW dirancang menggunakan substrat berpermitivitas tinggi Rogers RO4360

Passive and active components development for broadband applications

Recently, GaN HEMTs have been proven to have numerous physical properties, resulting in transistors with greatly increased power densities when compared to the other well-established FET technologies. This advancement spurred research and product development towards power-band applications that require both high power and high efficiency over the wide band. Even though the use of multiple narrow band PAs covering the whole band has invariably led to better performance in terms of efficiency and noise, there is an associated increase in cost and in the insertion loss of the switches used to toggle between the different operating bands. The goal, now, of the new technology is to replace the multiple narrow band PAs with one broadband PA that has a comparable efficiency performance. In our study here, we have investigated a variety of wide band power amplifiers, including class AB PAs and their implementation in distributed and feedback PAs.Additionally, our investigation has included switching-mode PAs as they are well-known for achieving a relatively high efficiency. Besides having a higher efficiency, they are also less susceptible to parameter variations and could impose a lower thermal stress on the transistors than the conventional-mode PAs. With GaN HEMTs, we have demonstrated: a higher than 37 dBm output power and a more than 30% drain efficiency over 0.02 to 3 GHz for the distributed power amplifier; a higher than 30 dBm output power with more than a 22% drain efficiency over 0.1 to 5 GHz for the feedback amplifier; and at least a 43 dBm output power with a higher than 63% drain efficiency over 0.05 to 0.55 GHz for the class D PA. In many communication applications, however, achieving both high efficiency and linearity in the PA design is required. Therefore, in our research, we have evaluated several linearization and efficiency enhancement techniques.We selected the LInear amplification with Nonlinear Components (LINC) approach. Highly efficient combiner and novel efficiency enhancement techniques like the power recycling combiner and adaptive bias LINC schemes have been successfully developed and verified to achieve a combined high efficiency with a relatively high linearity

Design and analysis of ultra-wide band and millimeter-wave antennas

Ph.DDOCTOR OF PHILOSOPH

Design and Development of Ultra Wide-Band Microwave Components for Snow-Probing Radars

This thesis describes the design and development of two different ultra-wideband microwave circuits for snow-probing radars. First, a broadband, low-loss planar quadrature hybrid coupler for the 2-20 GHz range is presented. The coupler offers better performance than commercially available options in terms of phase/amplitude imbalance and form factor. Next, a broadband, high-power T/R module with fast switching and integrated LNA is demonstrated to enable high altitude and multi-channel modes of operations of the CReSIS airborne snow radar along with automated surface tracking ability. The modules include a custom medium-power switch with an overall order of magnitude performance increase compared to commercially available duplexers/SPDT switch solutions. Pulsed mode operations at peak power levels exceeding 100 Watts (conservatively) can be supported with these devices and a demonstrated switching speed of less than 400 ns

Reader Design for Chipless Millimeter-Wave Identification (MMID)TAG

RÉSUMÉ L’identification par radiofréquence (RFID) est une technologie d'identification qui a de nombreuses applications utiles telles que le suivi des marchandises et les contrôles d’accès. RFID est une technique de transmission et réception à courte distance « sans-contact » pour envoyer des données ID à un lecteur à partir d’un objet marqué. Un système RFID se compose d’une étiquette de support de données, un lecteur, un middleware et une application d'entreprise. Tout d'abord, le signal transmis est généré par le lecteur, après une certaine distance de transmission dans l'espace libre, l’étiquette reçoit le signal détecté et après le traitement de signal ou codage du signal sur l'étiquette, le signal codé est renvoyé au lecteur. La réception et le traitement du signal seront finalement faits au récepteur. Cependant, la technologie RFID est entravée en raison de son prix élevé. Les étiquettes RFID sans puce résolvent le problème de coût et ont le potentiel de pénétrer aux marchés en grand public pour l’étiquetage de l’article à faible coût. Pour les étiquettes sans puce il n'y a pas de traitement de signal. Le traitement du signal se fait uniquement au niveau du lecteur. Ainsi, un lecteur qui est utilisé pour communiquer avec l’étiquette est également important dans un système de communication. Le domaine de fréquence ou la signature spectrale en fonction des étiquettes sans puce est un type d’étiquette sans puce. D'autre part, l'émetteur et le récepteur se composent d'un lecteur. Basé sur le principe de fonctionnement des étiquettes sans puce dans le domaine de fréquence, un lecteur comprend un émetteur et un récepteur utilisés pour communiquer avec une étiquette de fréquence et est présenté dans cette thèse. Tout d'abord, le principe de fonctionnement détaillé du système MMID sans puce, dans le domaine fréquentiel est introduit. D'autre part, sur la base du principe de fonctionnement, les spécifications de la conception du lecteur sont proposées. Plusieurs topologies différentes de la conception du lecteur seront comparées et la meilleure topologie sera sélectionnée pour la conception du lecteur. En second lieu, sur la base des spécifications du système de lecture et de la topologie sélectionnée, les résultats de simulation de la structure sélectionnée de lecteur sont présentés. Après les simulations, la conception du chaque composant est montré. Dans cette conception de système des circuits, tous les circuits passifs sont conçus et simulés dans HFSS et mesurés sur VNA. Tous les circuits actifs sont des puces commerciale de différentes compagnies. Les résultats des simulations et mesures de chaque circuit passif sont affichés.----------ABSTRACT Radiofrequency identification (RFID) technology is an identification technology that has many useful applications such as tracking goods and access controls. RFID is a touchless, short distance transmission and reception technique for ID data that is sent from a labeled object to a reader. A data-carrying tag, a reader, middleware and an enterprise application would make up a RFID system. Firstly, the transmitted signal is generated by the reader, the tag receiver, after a certain distance of transmission in free space, a detected signal and after processing signal or encoding signal on the tag, the encoded signal is then sent back to the reader. Signal receiving and processing part will be finally processed in the receiver. However, the RFID technology is hindered because of its high price tag. Chipless RFID tags solve the cost issues and have the potential to penetrate into mass markets for low-cost item tagging. For chipless tags, there is no signal processing in tags, the signal processing is done only in the reader. So a reader, which is used to communicate with the tag, is also important in a communication system. Frequency domain or spectral signature-based chipless tags are some kinds of chipless tag. On the other hand, transmitter and receiver are the core parts of a reader, based on the working principle of frequency domain chipless tags, a reader that includes a transmitter and a receiver used to communicate with frequency tag is presented in this dissertation. First of all, the detailed working principle of a chipless MMID system in the frequency domain is introduced. Based on the working principle, the specifications of the reader design are proposed. Several different topologies of the reader design will be compared and the best topology will be selected for our reader design. Secondly, based on the specifications of the reader system and the selected topology, the simulation results of the selected structure of the reader are presented. After the simulations, the design of each component is shown. In this system design, all the passive circuits are designed and simulated in HFSS and tested on VNA. All the active circuits are commercial chips from different companies. Simulation and measurement results for each passive circuit are given. Finally, the whole circuits including designed passive circuits and active circuits are integrated into a system board to create a reader system. There are two system boards finally fabricated, one transmitter board and one completed reader board. The transmitter board is tested firstly. Upon achieving good results of the transmitter board, the whole transceiver board is tested finally

A Wideband Multilayer Substrate Integrated Waveguide Cavity-Backed Slot Antenna Array

© 2017 IEEE. In this paper, a wideband 2 × 2 multilayer substrate integrated waveguide (SIW)-based cavity-backed slot array is proposed. The array element is constructed by stacking five layers of SIW cavity-backed slots and has a wide impedance bandwidth from 18 to 30 GHz. Two different feed networks based on probe coupling and slot coupling are introduced to maintain the wideband characteristic of the proposed element when employed in an array. Two 2 × 2 arrays fed by the proposed feed networks are designed, fabricated, and tested. The measured results show that both the arrays employing probe coupling and slot coupling feed networks have a wide impedance bandwidth over 30%. Within the obtained operation bands, good radiation performance is achieved. Moreover, advantages and disadvantages of the proposed two feed networks are discussed

Partially filled half-mode substrate integrated waveguide leaky-wave antenna for 24 GHz automotive radar

A novel highly efficient leaky-wave antenna (LWA), based on a periodic set of holes created in a half-mode substrate integrated waveguide (SIW), is conceived for automotive radar. The computer-aided design of this partially filled SIW (PFSIW) LWA is carried out using a full-wave electromagnetic simulator. As a proof-of-concept, an LWA prototype having a plate size of 15 x 126 mm(2) is fabricated through a standard low-cost printed circuit board (PCB) manufacturing process. Our manufactured prototype yields more than 25% impedance bandwidth, targeting the 24 GHz automotive short-range-radar band. Moreover, the measured peak gain and total antenna efficiency reach up to 15.5 dBi and 85% at 24 GHz. Furthermore, themain radiating direction steers continuously from 38 degrees to 58 degrees with an average half-power beamwidth of 12. when the operating frequency changes from 22 to 26 GHz. In comparison, a 160 mm long dielectric-filled SIW (DFSIW) LWA yields ameasured scanning range of 49 degrees and a total antenna efficiency of 43.8%, whereas an 80.3 mm long air-filled SIW (AFSIW) LWA exhibits a measured scanning range of 9 degrees and a total antenna efficiency of 80%. Therefore, PFSIW technology provides an optimal tradeoff between DFSIW and AFSIW for the envisaged short-range automotive radar application