A very compact dual-band LTCC module supporting WiMAX IEEE 802.16e-2005 and Wi-Fi IEEE 802.11a/b/g standards is presented. The frontend module (FEM) integrates in less than 50mm² all required passive and active functions for 1x2 (1 Transmit, 2 receive paths) MIMO operability. The FEM package has SMT compatible footprint and is 1.4mm high. Full FEM measurements results show good performance and fully validate the passive integration approach.
This paper reports on a design of a balanced filter based on a new lumped LC type balun. The realization disadvantages of conventional LC baluns integrated in a frontend module have been discussed and a new low profile lumpedelement balun has been proposed. The balanced filter is realized as a combination of a second order band pass filter and the novel LC balun with an additional low-pass circuit. The proposed layout has been realized using multilayer low temperature co-fired ceramic (LTCC) technology. The resulting structure exhibits excellent electrical performance, immunity to manufacturing tolerances and compactness. The realized low profile balanced filter is placed between two ground planes ensuring high electromagnetic compatibility which allows using this balanced filter as a building block of highly integrated WiMAX front-end modules.
This paper describes a design of a surface acoustic wave (SAW) ladder-type bandpass filter (BPF) for 2.4-2.5GHz ISM-band, based on the low temperature co-fired ceramic (LTCC) substrate, which can be used in 802.11b/g wireless LAN and Bluetooth applications. It obtains an excellent state-of-the-art performance in the ultra small package. The proposed architecture is based on a combination of SAW and low temperature co-fired ceramic (LTCC) technologies, where the multilayer LTCC substrate is used for integration of matching and passband-driving elements and for obtaining additional transmission zeros. It is comprised of three series and two parallel SAW resonators, realized on the LiTaO 3 piezoelectric substrate and connected accordingly to a ladder-type T-topology circuit design, and an additional resonator to obtain an attenuation at 2.57-2.62 GHz IMT-E (TDD) band. Two input/output matching inductors and three additional inductors, permitting to obtain a sufficient suppression level at 2.11-2.17 GHz UMTS (DL) band and harmonics, are completely integrated within ceramic.The described bandpass filter has ultra small dimensions of 1.1 x 1.4 x 0.9 mm, very low insertion losses of -1.5 dB max in the passband. This fully matched SAW bandpass filter has achieved excellent selectivity performance with the up-to-date smallest package size.Index Terms -Bandpass filter (BPF), ladder-type, surface acoustic wave (SAW), coexistence, low temperature co-fired ceramic (LTCC), wireless local area network (WLAN), systemin-package (SIP).
in many wireless communication systems, and they have been reported already [8]. Figure 6 shows the circuit schematic of a lumped element Ttype balun which an additional LC resonator. The LC resonator is used to achieve attenuation in second harmonic band. Figure 7 shows the measured performance of the implemented balun. The balun has an insertion loss of less than 0.9 dB, a return loss of more than 16.8 dB, an amplitude imbalance of 0.2 dB, and a phase difference of 175. 1-171.6 in the frequency range of 2.4-2.5 GHz. The good agreement between measured and simulated results is observed, as shown in Figure 7. The fabricated balun has seven pattern layers and the physical size is 1.7 Â 1.7 Â 0.44 mm 3 . RF FRONT-END MODULEThe proposed single-band RF FEM is implemented by combining a novel selectable filter with balun, and two PIN diodes for Tx and Rx path selection. Also, DC block capacitors are placed on top substrate. Figure 8 illustrates three-dimensional view and photograph of the fabricated single-band RF FEM. The LTCC substrate, which used in manufacturing the proposed RF FEM had a dielectric constant of 9.0, a loss tangent of 0.005 and a thickness of 40 lm. After cofiring, the thickness of the sheet had been 22 lm. The number of pattern layer in the fabricated RF FEM is nine including two inner grounds, and its thickness is 440 lm. The overall size of the module is less than 2.3 Â 4.0 mm 2 . The measured result of the RF FEM is shown in Figure 9. In case of Tx path, 2-GHz band has an insertion loss of 2.3 dB, an amplitude imbalance of 0.6 dB, a return loss of more than 16.8 dB and a phase difference of 177-171.7 . The second harmonic suppression is more than 39.7 dB in the frequency range of 4.8-5.0 GHz. In case of Rx path, 2-GHz band has an insertion loss of less than 1.2 dB, and a return loss of more than 16.7 dB. CONCLUSIONSIn this article, the compact and novel integrated single-band RF FEM for wireless communication system has been designed and implemented using LTCC technology. All passive components in a novel selectable filter are fully embedded in the substrate. The fabricated filter has seven pattern layers and it occupies less than 2.3 Â 2.3 Â 0.44 mm 3 . The measured results of the implemented filter are in good agreement with the simulated results. The implemented filter has low insertion loss and high attenuation at other passband. The RF FEM was realized by the proposed selectable filter with two PIN diodes at each output port for selecting Tx or Rx mode, and balun. It provided relatively low loss and occupied only 2.3 Â 4.0 Â 0.44 mm 3 . The proposed RF FEM can be low-loss and low-cost solution by removing MMIC SPDT switch in series connection. ABSTRACT: The analysis and design of an omnidirectional antenna that functions over a very broad frequency band is presented. Design guidelines for this antenna have been derived using electromagnetic analysis software. Measured results of a prototype developed according to these guidelines are presented. These results are compared to simulation...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.