DOCSLIB.ORG

Microwave Resonators

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Microwave Resonators Master Degree (LM) in Electronic Engineering MICROWAVES MICROWAVE RESONATORS Prof. Luca Perregrini Università di Pavia, Facoltà di Ingegneria [email protected] http://microwave.unipv.it/perregrini/ Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 1 SUMMARY Chapter 6 Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 2 SUMMARY • Series and Parallel Resonant Circuits • Loaded and Unloaded quality factor Q • Transmission Line Resonators • Rectangular Waveguide Cavity Resonators • Circular Waveguide Cavity Resonators • Dielectric Resonators • Excitation of Resonators • Cavity Perturbations Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 3 MOTIVATION Microwave resonators are used in a variety of applications, including filters, oscillators, frequency meters, and tuned amplifiers. The operation of microwave resonators is very similar to that of lumped- element resonators of circuit theory, therefore the basic characteristics of series and parallel RLC resonant circuits will be revised. Different implementations of resonators at microwave frequencies will be discussed, using distributed elements such as transmission lines, rectangular and circular waveguides, and dielectric cavities. Finally, the excitation of resonators using apertures and current sheets will be addressed. Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 4 SERIES RESONANT CIRCUIT The input impedance is and the complex power delivered to the load is Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 5 SERIES RESONANT CIRCUIT The active power lost in the RLC and the reactive powers of the inductor (magnetic) and of the capacitor (electric) are Therefore, the complex power and the input impedance can be written as Resonator losses represented by R may be due to conductor loss, dielectric loss, or radiation loss. Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 6 SERIES RESONANT CIRCUIT Resonance occurs when the average stored magnetic and electric energies are equal ( = ), and the input impedance at resonance become (purely real) From = , the resonant angular frequency = 2 results 0 0 Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 7 SERIES RESONANT CIRCUIT Another important parameter of a resonant circuit is the quality factor Q, defined as The quality factor is a measure of the loss of a resonant circuit (lower loss implies higher Q). If there is no interaction with an external network, this is called the unloaded Q. For the series resonant circuit the unloaded Q can be evaluated as Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 8 SERIES RESONANT CIRCUIT Since = 1/ , the input impedance can be written as 2 0 Near the resonant frequency, i.e. for = + with , we have 0 Δ Δ ≪ 0 and Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 9 SERIES RESONANT CIRCUIT The last formula for can also be used to infer how to model a lossy high-Q resonator by perturbation of his lossless counterpart. in The input impedance of a lossless series LC circuit is = = ( ) By substituting in 푗Δ 푗 − 0 1 + 2 0 0 0 → and remembering = / it results 0 0 = = 1 + = + ( ) = + ( ) 2 0 in 0 0 0 푗Δ 푗 − 0 0 푗 − 푗 − This procedure is general and applies to all the low-losses resonators. Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 10 SERIES RESONANT CIRCUIT The half-power fractional bandwidth BW of the resonator is defined as the percentage frequency bandwidth across with the active power delivered not less that one half of the maximum 0 Since the active power delivered to the resonator is = = 2 2 a in 2 the maximum active power resultsin in = , 2 / = BWa /max2 2 Therefore, since , the power is one half when Δ 0 = + (BW) = 2 2 2 2 from which in 0 1 BW = Microwaves, a.a. 2019/20 Prof. Luca0 Perregrini Microwave resonators, pag. 11 PARALLEL RESONANT CIRCUIT In the case of a parallel RLC circuit the results are similar. In particular, the quality factor is and the input impedance close to the resonance results Also in this case the half-power fractional bandwidth BW is 1 BW = See the Pozar’s book for more details and for the derivation. Microwaves, a.a. 2019/20 0 Prof. Luca Perregrini Microwave resonators, pag. 12 LOADED AND UNLOADED Q An external connecting network may introduce additional loss. Each of these loss mechanisms will have the effect of lowering the . For a series RLC, the effective resistance become + . For a parallel RLC, the effective resistance become /( + ). If we defineanexternal quality factor as then the loaded can be expressed as Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 13 LOADED AND UNLOADED Q In summary Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 14 TRANSMISSION LINE RESONATORS Open/short transmission lines of special length (half wavelength or quarter wavelength) can be used as resonators when lumped element circuits are unfeasible due to the high frequency. To study the quality factor, lossy transmission lines will be considered. Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 15 TRANSMISSION LINE RESONATORS Short-circuited / line At the resonant frequency = , the length of the line is = /2. 0 The input impedanceℓ is If we are interested in a small frequency band across , we can set = + ( ). 0 0 Δ Moreover,0 if the mode propagating is TEM ( = = ) and 1, we have Δ ≪ + ℓ 2 0 αℓ ≪ tan = tan = tan + tanh 0 Δ Δ Δ ℓ ℓ 0 ≈ 0 αℓ ≈ αℓ Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 16 TRANSMISSION LINE RESONATORS Short-circuited / line By substituting and observing that / 1, the approximated input impedance results Δℓ 0 ≪ It can be cast in the form, which is the same expression of the series RLC circuit. The lumped element values are The quality factor is Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 17 TRANSMISSION LINE RESONATORS Short-circuited / line At the resonant frequency = , the length of the line is = /4. 0 The input impedanceℓ is We are interested in a small frequency band across : = + ( ). Moreover, if the0 mode propagating0 is TEM0 ( = = ) and 1, we have Δ Δ ≪ ℓ 4 20 αℓ ≪ cot = cot + = tan tanh 2 2 2 2 Δ Δ Δ ℓ 0 − 0 ≈ − 0 αℓ ≈ αℓ Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 18 TRANSMISSION LINE RESONATORS Short-circuited / line By substituting and observing that /(2 ) 1, the approximated input impedance results Δℓ 0 ≪ It can be cast in the form, which is the same expression of the parallel RLC circuit. The lumped element values are The quality factor is Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 19 TRANSMISSION LINE RESONATORS Open-circuited / line At the resonant frequency = , the length of the line is = /2. 0 The input impedanceℓ is We are interested in a small frequency band across : = + ( ). 0 0 Δ Δ ≪ 0 Moreover, if the mode propagating is TEM ( = = ) and 1, we have ℓ 2 0 αℓ ≪ tan = tan + tanh Δ Δ ℓ 0 ≈ 0 αℓ ≈ αℓ Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 20 TRANSMISSION LINE RESONATORS Open-circuited / line By substituting and observing that / 1, the approximated input impedance results Δℓ 0 ≪ It can be cast in the form, which is the same expression of the parallel RLC circuit. The lumped element values are The quality factor is Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 21 TRANSMISSION LINE RESONATORS Let’s consider a resonator comprising many sections of transmission lines with different characteristic impedances , , …, , loaded at the extremes with arbitrary reactive impedances and : 1 2 1 2 The characteristic equationtodetermine the resonant frequencies can be obtained by cutting the structure in any section and imposing the condition = ∗ Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 22 RECTANGULAR WAVEGUIDE CAVITY RESONATORS Waveguide cavities can be made without dielectrics, and therefore they are preferred when high-Q is required. A cavity based on a rectangular waveguide is usually obtained by short circuiting the waveguide at both ends. An infinite number of modes resonate in the cavity, and they can be derived from propagating TE and TM modes in the waveguide. The resonant frequencies and field expressions will be derived under the hypothesis of a lossless resonator. The Q factor will be derived by using a perturbation technique. Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 23 RECTANGULAR WAVEGUIDE CAVITY RESONATORS It is sufficient to impose the perfect electric wall condition at = 0, to the field of the TE or TM propagating modes to determine the resonant frequency and the resonant modal field. Enforcing , , 0 = , , = 0 leads to � � and, therefore where Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 24 RECTANGULAR WAVEGUIDE CAVITY RESONATORS The resonance wavenumber is therefore and the resonance frequency results If < < the dominant resonant mode (lowest resonant frequency) will be the TE101 mode, corresponding to the TE10 dominant waveguide mode in a shorted guide of length /2. The dominant TM resonant mode is the TM mode. 110 Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 25 RECTANGULAR WAVEGUIDE CAVITY RESONATORS Unloaded Q of the TE mode To evaluate the Q, we10needℓ to determine the electric and magnetic stored energies, as well as the dissipated power. Taking into account the expression of the field of the propagating TE10 mode, and using the conditions deriving from the enforcement of the resonance, the resonant field results Microwaves, a.a. 2019/20 Prof. Luca Perregrini Microwave resonators, pag. 26 RECTANGULAR WAVEGUIDE CAVITY RESONATORS Unloaded Q of the TE mode The stored energies are10ℓderived with some simple calculations: Since and , we have and, therefore, Microwaves, a.a.
Load more

Recommended publications
  • High Q Tunable Filters
    High Q Tunable Filters by Fengxi Huang A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Doctor of Philosophy in Electrical and Computer Engineering Waterloo, Ontario, Canada, 2012 ©Fengxi Huang 2012 AUTHOR'S DECLARATION I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii Abstract Microwave tunable filters are key components in radar, satellite, wireless, and various dynamic communication systems. Compared to a traditional filter, a tunable filter is able to dynamically pass the required signal and suppress the interference from adjacent channels. In reconfigurable systems, tunable filters are able to adapt to dynamic frequency selection and spectrum access. They can also adapt to bandwidth variations to maximize data transmission, and can minimize interferences from or to other users. Tunable filters can be also used to reduce size and cost in multi-band receivers replacing filter banks. However, the tunable filter often suffers limited application due to its relatively low Q, noticeable return loss degradation, and bandwidth changing during the filter tuning. The research objectives of this thesis are to investigate the feasibility of designing high Q tunable filters based on dielectric resonators (DR) and coaxial resonators. Various structures and tuning methods that yield relatively high unloaded Q tunable filters are explored and developed. Furthermore, the method of designing high Q tunable filters with a constant bandwidth and less degradation during the tuning process has been also investigated.
    [Show full text]
  • Tailoring Dielectric Resonator Geometries for Directional Scattering and Huygens’ Metasurfaces
    Tailoring dielectric resonator geometries for directional scattering and Huygens’ metasurfaces Salvatore Campione,1,2,* Lorena I. Basilio,2 Larry K. Warne,2 and Michael B. Sinclair2 1Center for Integrated Nanotechnologies (CINT), Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185, USA 2Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185, USA * [email protected] Abstract: In this paper we describe a methodology for tailoring the design of metamaterial dielectric resonators, which represent a promising path toward low-loss metamaterials at optical frequencies. We first describe a procedure to decompose the far field scattered by subwavelength resonators in terms of multipolar field components, providing explicit expressions for the multipolar far fields. We apply this formulation to confirm that an isolated high-permittivity dielectric cube resonator possesses frequency separated electric and magnetic dipole resonances, as well as a magnetic quadrupole resonance in close proximity to the electric dipole resonance. We then introduce multiple dielectric gaps to the resonator geometry in a manner suggested by perturbation theory, and demonstrate the ability to overlap the electric and magnetic dipole resonances, thereby enabling directional scattering by satisfying the first Kerker condition. We further demonstrate the ability to push the quadrupole resonance away from the degenerate dipole resonances to achieve local behavior. These properties are confirmed through the multipolar expansion and show that the use of geometries suggested by perturbation theory is a viable route to achieve purely dipole resonances for metamaterial applications such as wave-front manipulation with Huygens’ metasurfaces. Our results are fully scalable across any frequency bands where high-permittivity dielectric materials are available, including microwave, THz, and infrared frequencies.
    [Show full text]
  • Dielectric Resonator Oscillator Design and Realization at 4.25 Ghz
    ELECO 2011 7th International Conference on Electrical and Electronics Engineering, 1-4 December, Bursa, TURKEY Dielectric Resonator Oscillator Design and Realization at 4.25 GHz Şebnem SEÇKİN UĞURLU Department of Electrical and Electronics Engineering Dokuz Eylül University, Izmir, TURKEY [email protected] Abstract device in our circuit. The negative resistance oscillator model is chosen for the design. In the following sections, the design In this paper design and realization of dielectric resonator procedure of the DRO will be considered. oscillator operating 4.25 GHz is explained. The oscillator is designed as a negative resistance oscillator where chip- 2.1 DRO Simulation amplifier is used as the negative resistance by adding feedback. The dielectric resonator is simulated using High The placement of the resonator is an important parameter. Frequency Structure Simulator. The simulation and The width and the length of the microstrip line, as well as the realization results are discussed. distance of the resonator to the microstrip line must be thoroughly analyzed. The resonator is modeled as parallel RLC 1. Introduction resonant circuit and RLC parameters as well as quality factors are calculated from the simulated S-parameter values. It was first presented by R.D. Richtymer [1] that cylindrical For the microstrip substrate, Taconic TLY 3 CH is used. The dielectric structure would act like a resonator. Many years after substrate has a relative dielectric constant of the 2.33 ±.02 and that discovery, such circuits containing dielectric resonators are substrate height of 0.76 mm. As the dielectric resonator, Trans- realized. Tech 8300 series dielectric resonator is used.
    [Show full text]
  • Geometry Perturbation of Dielectric Resonator for Same Frequency Operation As Radiator and Filter
    32nd URSI GASS, Montreal, 19–26 August 2017 Geometry Perturbation of Dielectric Resonator for Same Frequency Operation as Radiator and Filter Taomia T. Pramiti*(1), Mohamed A. Moharram(1), and Ahmed A. Kishk(1) (1) Electrical and Computer Engineering Department, Concordia University, Montréal, Québec, Canada Abstract using the TM01d mode that provide omnidirectional radia- tion pattern at 2.45GHz. However, having the DR sits on A single dielectric resonator is used for a dual functional a ground plane suppress the TE01d mode. Therefore, it application using the geometry perturbation method at the has to be lifted up using the dielectric substrate. On the desired frequency. The high Q TE01d mode for a filter oper- other hand the resonance frequency of TE01d mode and ation and the low Q TM01d mode for radiation at the same TM01d mode are different. Therefore, geometry perturba- frequency. To operate both modes at the same frequency tion is used to tune the resonance frequency of both modes a circular metallic disk is used to control the energy con- to operate within their bandwidths. In addition, a metallic centrations of the modes inside the dielectric resonator. In disk is placed on the top of the resonator to provide par- addition,a metal disk is used to provide partial shielding for tial shielding for the TE01d mode to enhance its Q-factor. the TE01d mode and allow the TM01d mode radiation and In the design, the metallic disc is also used to improve the at the same time enhance the insertion loss and matching. filter insertion loss without significant effect on the radiat- The design is made for Wi-Fi applications at 2.45 GHz.
    [Show full text]
  • High Dielectric Permittivity Materials in the Development of Resonators Suitable for Metamaterial and Passive Filter Devices at Microwave Frequencies
    ADVERTIMENT. Lʼaccés als continguts dʼaquesta tesi queda condicionat a lʼacceptació de les condicions dʼús establertes per la següent llicència Creative Commons: http://cat.creativecommons.org/?page_id=184 ADVERTENCIA. El acceso a los contenidos de esta tesis queda condicionado a la aceptación de las condiciones de uso establecidas por la siguiente licencia Creative Commons: http://es.creativecommons.org/blog/licencias/ WARNING. The access to the contents of this doctoral thesis it is limited to the acceptance of the use conditions set by the following Creative Commons license: https://creativecommons.org/licenses/?lang=en High dielectric permittivity materials in the development of resonators suitable for metamaterial and passive filter devices at microwave frequencies Ph.D. Thesis written by Bahareh Moradi Under the supervision of Dr. Juan Jose Garcia Garcia Bellaterra (Cerdanyola del Vallès), February 2016 Abstract Metamaterials (MTMs) represent an exciting emerging research area that promises to bring about important technological and scientific advancement in various areas such as telecommunication, radar, microelectronic, and medical imaging. The amount of research on this MTMs area has grown extremely quickly in this time. MTM structure are able to sustain strong sub-wavelength electromagnetic resonance and thus potentially applicable for component miniaturization. Miniaturization, optimization of device performance through elimination of spurious frequencies, and possibility to control filter bandwidth over wide margins are challenges of present and future communication devices. This thesis is focused on the study of both interesting subject (MTMs and miniaturization) which is new miniaturization strategies for MTMs component. Since, the dielectric resonators (DR) are new type of MTMs distinguished by small dissipative losses as well as convenient conjugation with external structures; they are suitable choice for development process.
    [Show full text]
  • Dielectric Resonators
    DIELECTRIC RESONATORS MDR24 SERIES – Ultra High Q Temperature Stable Dielectric Resonators - TE Mode INTRODUCTION MDR24 Series is a specially formulated dielectric material that exhibits Ultra High Q at frequencies between 1.5 and 18 GHz with Qf > 300,000 at 10 GHz. Dielectric Constant is 24 with very tight tolerance. It is ideally suited for high frequency applications where extreme low loss and excellent temperature stability is required. MDR24 Series resonators are available in both disk and cylinder type with or with supports to minimize losses. We recommend alumina and forsterite supports to maintain high Qu factor. Material Characteristics Dielectric Constant ------------------------------------------------------------------------- 24 ± 1 (+/-0.5 Special) o Temperature Coefficient of Resonant Frequency ( τƒ) (ppm/ C) ---------------- 1 to 3 ± 1 Qf (1/tan δ x frequency in GHz) ---------------------------------------------------------- >300,000 @ 10 GHz Thermal Expansion (ppm/ oC) (20 oC) ---------------------------------------------------- >10 Thermal Conductivity (cal/cm-sec oC) @ 25 oC ---------------------------------------- ~ 0.006 Specific Heat (Cal/g oC) -------------------------------------------------------------------- 0.07 Density (g/cc) -------------------------------------------------------------------------------- 7.5 Composition --------------------------------------------------------------------------------- Tantalum Based Color -------------------------------------------------------------------------------------------
    [Show full text]
  • High Performance Microwave Integrated Filters for 5G Applications
    High Performance Microwave Integrated Filters for 5G Applications by Jiacheng Zhang A thesis submitted to the Faculty of Graduate and Postdoctoral Affairs in partial fulfillment of the requirements for the degree of Master of Applied Science in Electrical and Computer Engineering Carleton University Ottawa, Ontario © 2019 Jiacheng Zhang Abstract A 71-76GHz millimeter-wave filter is designed and implemented in a multilayer LTCC module to help attenuate the side spur signal level. The filter is aimed to be embedded in a novel E-band architecture designed at Huawei for millimeter-wave signal communication application. The goal of the filter is to help reduce the third harmonic and fourth harmonic leakage of the LO signal from tripler into the RF channel. Through measurement, for -15dBm received signal power, the 3rd and 4th harmonic leakage levels sof the LO signal is around -25dBc, and both of their frequency range are very close to the transmission band. The designed bandpass filter attenuates the 3rd and 4th harmonic signal power down to -50dBc with a low filter order and small physical size. Unfortunately, access to the fabricated filter was not possible due to existing political tension between the US government and Huawei. The fabricated filter was not shipped to Ottawa, and as a result, it was not measured. A second bandpass filter operating at 10GHz is fabricated using Rogers4360 substrate for measurement and validation. The measurement results show some deviations with simulation results. The center frequency shifts from 10GHz to 11.25GHz. Through analysis, the milling depth of the fabrication process affects the measurement result.
    [Show full text]
  • Appendix. Analysis of Resonator Properties Using General-Purpose Microwave Simulator
    Appendix. Analysis of Resonator Properties Using General-Purpose Microwave Simulator A.I Design Parameters of Direct-Coupled Resonator BPF As previously described, bandpass filters in the RF and microwave regions are generally realized by the cascaded connection of plural resonators with uni­ form structure using appropriate coupling circuits. Starting with given filter specifications (e.g., center frequency, pass-band bandwidth, VSWR, insertion loss, attenuation at specified frequency, etc.), the first step in a filter synthe­ sis procedure is to obtain the filter design parameters, such as the required stage number n, element values 9j, and unloaded-Q, after choosing the filter response type of Chebyschev or Butterworth. In accordance with these fun­ damental parameters, the next step is to calculate the electrical parameters and/or structural parameters based on the applied resonator structure. Filter design based on lumped-element LC resonators and lumped-element coupling circuits allow direct calculation of the electrical parameters. Con­ trarily, in the high frequency regions such as RF and microwave bands, distributed-element circuits are often applied to filtering devices, and thus both electrical and structural parameters are required for filter design. Since filter design theories have been generalized and systematized based on lumped-element circuit theory, the electrical parameters are first calculated by approximating distributed circuits into lumped-element circuits, which are in turn converted into the structural parameters determining resonator design. Filter design can easily be obtained when the conversion between electrical and structural parameters is analytically derived and expressed in the form of a mathematical equation. Yet for complicated geometrical structures, gener­ alized conversion equations become difficult to derive, and thus experimental results are often combined with analytical expressions in order to obtain the structural parameters.
    [Show full text]
  • Microwave and Millimeter-Wave High-Q Micromachined Resonators
    Microwave and Millimeter-Wave High-Q Micromachined Resonators Andrew R. Brown,1 Pierre Blondy,2 Gabriel M. Rebeiz1 1 Radiation Laboratory, Department of Electrical Engineering, University of Michigan, Ann Arbor, Michigan 48109; e-mail: [email protected] and [email protected] 2 IRCOM, University of Limoges, Limoges, France; e-mail: [email protected] Recei¨ed 29 June 1998; re¨ised 19 December 1998 ABSTRACT: Alternative techniques for integrating high-quality factor resonators using micromachining techniques have been investigated. Two methods are presented which include suspending microstrip lines on thin dielectric membranes, resulting in an effective dielectric constant of near unity, and integrating three-dimensional micromachined wave- guide cavity resonators with planar feedlines. These resonators show large improvements in quality factor over conventional techniques, and more importantly, allow for planar integra- tion in complex systems. Resonators were fabricated in suspended microstrip at 29, 37, and 62 GHz with quality factors of over 450 with very close agreement between simulated and measured results. An integrated micromachined cavity resonator was also fabricated with a TE011 resonance quality factor of 1117 at 24 GHz and a TE021 resonance quality factor of 1163 at 38 GHz. To the authors' knowledge, these are the highest quality factor planar resonators without the use of superconductive materials, and can be used in microwave and millimeter-wave low-loss ®lters and low-phase-noise oscillators. ᮊ 1999 John Wiley & Sons, Inc. Int J RF and Microwave CAE 9: 326᎐337, 1999. Keywords: millimeter wave; high-Q resonators; micromachining; packaging techniques I. INTRODUCTION Current millimeter-wave wireless front-end transceivers use a hybrid approach with a combi- Microwave and millimeter-wave communication nation of waveguide components, solid-state de- systems are expanding rapidly as they offer many vices, and dielectric resonatorsŽ.
    [Show full text]
  • Design of Dielectric Resonator Antenna Using Dielectric Paste
    sensors Article Design of Dielectric Resonator Antenna Using Dielectric Paste Hauke Ingolf Kremer 1, Kwok Wa Leung 1,*, Wai Cheung Wong 1, Kenneth Kam-Wing Lo 2 and Mike W. K. Lee 1 1 Department of Electrical Engineering, City University of Hong Kong, Hong Kong 999077, China; [email protected] (H.I.K.); [email protected] (W.C.W.); [email protected] (M.W.K.L.) 2 Department of Chemistry, City University of Hong Kong, Hong Kong 999077, China; [email protected] * Correspondence: [email protected] Abstract: In this publication, the use of a dielectric paste for dielectric resonator antenna (DRA) design is investigated. The dielectric paste can serve as an alternative approach of manufacturing a dielectric resonator antenna by subsequently filling a mold with the dielectric paste. The dielectric paste is obtained by mixing nanoparticle sized barium strontium titanate (BST) powder with a silicone rubber. The dielectric constant of the paste can be adjusted by varying the BST powder content with respect to the silicone rubber content. The tuning range of the dielectric constant of the paste was found to be from 3.67 to 18.45 with the loss tangent of the mixture being smaller than 0.044. To demonstrate the idea of the dielectric paste approach, a circularly polarized DRA with wide bandwidth, which is based on a fractal geometry, is designed. The antenna is realized by filling a 3D-printed mold with the dielectric paste material, and the prototype was found to have an axial ratio bandwidth of 16.7% with an impedance bandwidth of 21.6% with stable broadside radiation.
    [Show full text]
  • Dielectric Resonator Antennas Using High Permittivity Ceramics
    Ceramics International 30 (2004) 1211–1214 Dielectric resonator antennas using high permittivity ceramics Zhen Peng∗, Hong Wang, Xi Yao Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, Xi’an Jiaotong University, Xi’an 710049, China Received 28 November 2003; received in revised form 20 December 2003; accepted 22 December 2003 Available online 19 July 2004 Abstract The dielectric resonator (DR) antennas with probe-feed in both cylindrical and rectangular shape using high permittivity ceramics were investigated. The bismuth-based low-firing ceramics with the dielectric constants of 97, 71 and 37 were adopted as dielectric materials, respectively. The result of theoretical calculation and experimental measurement are presented and analyzed. © 2004 Elsevier Ltd and Techna Group S.r.l. All rights reserved. Keywords: Dielectric resonator antenna; High permittivity; Bismuth-based ceramic 1. Introduction 2. Experimental Dielectric resonators (DRs) have been widely used in 2.1. Dielectric ceramics shielded microwave circuits, such as cavity resonator, filters and oscillators. In recent years, application of these com- The ceramics used in this paper are bismuth-based ponents as antennas in microwave and millimeter band has low-firing ceramics Bi3xZn2−3x−yAy(ZnxNb2−x−zBz)O7 been extensively studied [1–4], as they had the advantages (A = Ca2+,B= Sb5+,Ti4+, x = 0.5–0.67, y = 0.2–0.3, such as light weight, low cost, small size, low profile, high z = 0.2–1.4) with the dielectric constants of 97, 71 and radiation efficiency, large bandwidth and ease of integration 37, respectively [17]. These ceramics with permittiviy in with other active or passive microwave integrated circuit series were synthesized by the conventional solid-state re- (MIC) components.
    [Show full text]
  • Design of a 5.305 Ghz Dielectric Resonator Oscillator with Simulation and Optimization
    342 JOURNAL OF ELECTRONIC SCIENCE AND TECHNOLOGY OF CHINA, VOL. 6, NO. 3, SEPTEMBER 2008 Design of a 5.305 GHz Dielectric Resonator Oscillator with Simulation and Optimization Jina Wan Abstract⎯The design of a 5.305 GHz series feedback It is made of ceramic material with high dielectric constant, free running dielectric resonator oscillator (DRO) is high Q factor (typically 9000 at 10 GHz), and low presented. Its simulation and optimization are realized temperature coefficient (typically ±6 ppm/°C). The most by obtaining the unloaded Q factor of the cavity frequently used DR shapes are disc and puck since they can dielectric resonator (DR) and analyzing the linear and be easily manufactured than other shapes. nonlinear models of the DRO. CAD packages of A DR puck with diameter of 7.05 mm, thickness of DR_Rez and Agilent Advance Design System (ADS) are 2.65 mm, and dielectric constant of 88 is used in current used and the best tradeoff among the output power, design. It is housed in a copper cavity. The unloaded Q phase noise, and frequency stability is achieved. With factor with cavity effect is simulated by DR_Rez package, the result of simulation, a physical oscillator prototype is which can provide better uncertainty than traditional CARD constructed. The measured results show the good package. The simulation result shows that the unloaded Q agreement with those of simulation. factor for the cavity resonator Q is 6406. u Index Terms⎯ Agilent advance design system (ADS), The DR puck is closely positioned to a 50Ω-straight- dielectric resonator oscillator (DRO), negative resistance, microstrip line which is terminated with a 50 Ω resistor to unloaded Q factor .
    [Show full text]