Design of Small-size and Low-loss LTCC Filters on Capacitively Loaded Cavities

2015 ◽  
Vol 2015 (CICMT) ◽  
pp. 000172-000183
Author(s):  
Viacheslav Turgaliev ◽  
Dmitry Kholodnyak ◽  
Jens Müller ◽  
Matthias A. Hein

Design of microwave filters for portable electronics is complicated by conflicting requirements to be met simultaneously such as high selectivity, low insertion loss and compact size. Substrate integrated waveguide (SIW) technology allows designing low-profile high-Q resonators and low-loss bandpass filters based thereof. However, SIW filters are not well-suited for telecommunication applications because of remarkably large size in plane. The size of a SIW cavity can be dramatically reduced by a capacitive loading. Capacitively loaded cavities (CLCs) operating in the TM110 mode can be as small as 1/8 of the guided wavelength and even smaller, i.e. comparable in size with lumped-element resonators. Although the unloaded Q-factor decreases proportionally to cavity size, miniaturized CLCs can exhibit much higher Q-factor than that of lumped-element resonators. This paves the way for designing small-size and low-loss filters for wireless communications and different applications. Miniaturized capacitively loaded SIW cavities are favorably implemented by means of the low temperature co-fired ceramics (LTCC) technology. The goal of the paper is to demonstrate manifold possibilities and flexibility offered by the LTCC technology to the design of advanced microwave filters on CLCs. Different design and manufacturing aspects are considered. Various design examples of high-performance LTCC resonators and filters for single- and dual-band wireless applications are presented. The designed resonators and filters were manufactured using the commercial DuPont Green Tape 951 LTCC system. The LTCC filters on miniaturized CLCs are shown advantageous with regard to small size, low loss, and absence of spurious response over a wide frequency range.

2019 ◽  
Vol 11 (7) ◽  
pp. 694-702
Author(s):  
Murli Manohar ◽  
Rakhesh Singh Kshetrimayum ◽  
Anup Kumar Gogoi

AbstractA low profile super-wideband polarization diversity printed monopole antenna with dual band-notched characteristics is presented the first time. The designed antenna comprises two arched shaped radiating elements with two triangular tapered microstrip feed lines (TTMFL) and two arched shaped partial ground planes, which covers an enormously wide impedance bandwidth (BW) from 1.2 to 25 GHz (ratio BW of 20.8:3) for reflection coefficient |S11| < −10 dB. To ensure the high port isolation (better than − 30 dB) between two feeding ports over the whole bands, two analogous antennas have been kept perpendicular to each other at a distance of 1 mm. In addition, the dual band-notched performance in wireless local area network (5–6 GHz) and X-band (7.2–8.5 GHz) is generated by employing a pair of open-circuited stubs (L-shaped stub and horizontal stub) to the TTMFL. Envelop correlation coefficient has been computed to study the polarization diversity performance. Finally, the proposed antenna was fabricated and tested successfully. Measured results indicate that the proposed antenna is an appropriate candidate for the polarization diversity applications. The proposed antenna has a compact size of 40 × 70 × 0.787 mm3, high isolation, and occupies a small space compared with the existing antennas.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Mahdi Jalali ◽  
Tohid Sedghi ◽  
Shahin Shafei

A novel configuration of a printed monopole antenna with a very compact size for satisfying WLAN operations at the 5.2/5.8 GHz and also for X-band operations at the 10 GHz has been proposed. The antenna includes a simple square-shaped patch as the radiator, the rotated U-shaped conductor back plane element with embedded strip on it, and the partial rectangular ground surface. By using the rotated U-shaped conductor-backed plane with proper values, good impedance matching and improvement in bandwidth can be achieved, at the lower and upper bands. The impedance bandwidth forS11<-10 dB is about 1.15 GHz for 5 GHz band and 5.3 GHz for X-band. The measured peak gains are about 1.9 dBi at WLAN-band and 4.2 dBi at X-band. The experimental results represent that the realized antenna with good omnidirectional radiation characteristics, enough impedance bandwidth, and reasonable gains can be appropriate for various applications of the future developed technologies and handheld devices.


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 786
Author(s):  
Prannoy Agrawal ◽  
Daniel Kienemund ◽  
Dominik Walk ◽  
Stipo Matic ◽  
Nicole Bohn ◽  
...  

This work presents a method for reducing acoustic resonances in ferroelectric barium strontium titanate (BST)-based bulk ceramic varactors, which are capable of operation in high-power matching circuits. Two versions of parallel-plate varactors are manufactured here: one with pure BST and one with 10 vol-% magnesium borate, Mg3B2O6 (MBO). Each varactor includes a 0.85-mm-thick ferroelectric layer. Acoustic resonances that are present in the pure BST varactor are strongly suppressed in the BST-MBO varactor and, hence, the Q-factor is increased over a wide frequency range by the addition of small amounts of a low-dielectric-constant (LDK) MBO. Although the tunability is reduced due to the presence of non-tunable MBO, the increased Q-factor extends the varactor’s availability for low-loss and high-power applications.


Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1191
Author(s):  
Richard Syms ◽  
Adam Bouchaala

Micro-electromechanical systems (MEMS) bandpass filters based on arrays of electrostatically driven coupled beams have been demonstrated at MHz frequencies. High performance follows from the high Q-factor of mechanical resonators, and electrostatic transduction allows tuning, matching and actuation. For high-order filters, there is a conflict between the transduction mechanism and the coupling arrangement needed for dynamic synchronization: it is not possible to achieve synchronization and tuning simultaneously using a single voltage. Here we propose a general solution, based on the addition of mass-loaded beams at the ends of the array. These beams deflect for direct current (DC) voltages, and therefore allow electrostatic tuning, but do not respond to in-band alternating current (AC) voltages and hence do not interfere with synchronization. Spurious modes generated by these beams may be damped, leaving a good approximation to the desired response. The approach is introduced using a lumped element model and verified using stiffness matrix and finite element models for in-plane arrays with parallel plate drives and shown to be tolerant of the exact mass value. The principle may allow compensation of fabrication-induced variations in complex filters.


2019 ◽  
Vol 8 (2S11) ◽  
pp. 2111-2113

The present paper relates to an antenna with circular patch micro-strip for the applications of c band. The antenna has advantages like low profile and high selectivity, compact size, less weight. A circular type patch is chosen for the antenna over a rectangle type patch due to some advantages of circular type antenna. The size of the antenna is 60mm x 60mm x 0.8mm with an array of 3×2 size. The specification for the FR4 epoxy type substrate are: 0.8mm height and 4.4 value of permittivity. The implemented antenna designing carries characteristics of dual band and the two resonating frequencies are 5.7 GHz and 6.06 GHz which gives significant gain. The simulation is done by using a HFFS software.


2013 ◽  
Vol 397-400 ◽  
pp. 1967-1971
Author(s):  
Guo Xing Jiang

Antenna is all important part of GPS receivers,there is a great need for the design and production of new antennas which are fully compatible with modernized signals. Because of their advantages such as low cost, compact size, low profile,ability to support dual-frequency and circular polarization operation, microstrip patch antennas have become widely used in GPS antenna designs. A circular polarization patch antennas are proposed in the paper. The antenna designed to operate at L1(1575.42MHz) and L5(1176.45MHz)frequency bands. Initially, a comer-truncated patch antenna for GPS L1 operation was designed to validate simulation in Ansoft High Frequency Structure Simulator(HFSS), the results obtained for this antenna were used to design the two proposed antennas,and designed antennas are presented.


2019 ◽  
Vol 7 (2) ◽  
pp. 34-37
Author(s):  
Abbas Rezaei ◽  
Salah I. Yahya

This work presents a novel microstrip dual-band bandpass filter (BPF) using meandros spirals and patch cells, which is proposed for the first time by this work. It occupies a very compact size of 0.0017 λg2. The proposed filter is designed to operate at Fo1=0.85 GHz and Fo2=1.85 GHz for GSM-850/GSM-1900 applications. In addition to the small size, it has several advantages in terms of wide fractional bandwidths (FBW), low insertion losses and high return losses at both channels. The simulated insertion losses at the lower and upper passbands are 0.05 dB and 0.1 dB, respectively. Another advantage of the proposed BPF of this work is the attenuated harmonics, where it is able to suppress 1st, 2nd, 3rd and 4th harmonics (4.11 Fo1) with -20 dB maximum harmonic level.


2012 ◽  
Vol 424-425 ◽  
pp. 573-576
Author(s):  
Jin Ping Hu ◽  
Guo Hui Li ◽  
Wei Dong Fang ◽  
Wei Zhang ◽  
Hai Ping Hu

A narrowband dual-band bandpass filter based on step impedance resonator (SIR) is proposed in this paper to realize high performance with a compact size. The center frequencies of the designed filter are 2.4 and 5.8GHz, where it is suitable for wireless communication system. The absolute bandwidth approaches 200MHz with 8.3% fractional bandwidth at -3dB, and the simulations show that the return loss of the first and the second band is lower than -20dB. Between the two passbands, there is a transmission zero which can achieve a high out-band isolation. For demonstration, the filter has been fabricated and the measurement results show the excellent agreement with the theoretical simulation results


2017 ◽  
Vol 26 (10) ◽  
pp. 1750163 ◽  
Author(s):  
Mohammad Babajanzadeh ◽  
Massoud Dousti

Design, fabrication and measurement of a high-selectivity dual-mode dual-band bandpass filter are presented in this paper. The resonance frequencies of the filter are 1.8[Formula: see text]GHz and 2.4[Formula: see text]GHz which are generated by a meander-loop resonator and a square-loop resonator. The two dual-mode single-band-loop resonators are stacked on each other and create a dual-band bandpass filter. Some advantages of our design are compact size, high selectivity, low loss and also no dependence of two bands, resonance frequencies on each other. The measurement results exhibit that the minimum insertion losses are 0.19[Formula: see text]dB for 1.8[Formula: see text]GHz and 0.32[Formula: see text]dB for 2.4[Formula: see text]GHz. Moreover return losses are better than 43.2[Formula: see text]dB and 40.6[Formula: see text]dB for 1.8[Formula: see text]GHz and 2.4[Formula: see text]GHz, respectively. The proposed filter has a size of [Formula: see text][Formula: see text]mm2. This microstrip filter is fabricated on RT/Duroid6010 substrate with dielectric constant 10.8 and thickness 1.27[Formula: see text]mm and its equivalent circuit is also offered. The measured results exhibit good agreement with the simulated ones.


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